Cogprints: No conditions. Results ordered -Date, Title. 2018-01-17T14:26:22ZEPrintshttp://cogprints.org/images/sitelogo.gifhttp://cogprints.org/2016-03-24T19:12:24Z2016-03-24T19:12:24Zhttp://cogprints.org/id/eprint/10088This item is in the repository with the URL: http://cogprints.org/id/eprint/100882016-03-24T19:12:24ZA Precise Measure of Working Memory Reveals Subjects
Difficulties Managing Limited CapacityFree recall consists of two separate stages: the emptying of working memory and reactivation [1]. The Tarnow Unchunkable Test (TUT, [2]) uses double integer items to separate out only the first stage by making it difficult to reactivate items due to the lack of intra-item relationships.
193 Russian college students were tested via the internet version of the TUT. The average number of items remembered in the 3 item test was 2.54 items. In the 4 item test, the average number of items decreased to 2.38. This, and a number of other qualitative distribution differences between the 3 and 4 item tests, indicates that the average capacity limit of working memory has been reached at 3 items. This provides the first direct measurement of the unchunkable capacity limit of language based items.
That the average number of items remembered decreased as the number of items increased from 3 to 4 indicates that most subjects were unable to manage their working memories as the number of items increased just beyond the average capacity. Further evidence for the difficulty in managing the capacity limit is that 25% of subjects could not remember any items correctly at least in one of three 4 item tests and that the Pearson correlation between the 3 item and 4 item subject recalls was a relatively small 38%.
This failure of managing a basic memory resource should have important consequences for pedagogy including instruction, text book design and test design. Because working memory scores are important for academic achievement, it also suggests that an individual can gain academically by learning how to manage her or his capacity limit.
Regina Ershovaerchovareg@mail.ruEugen Tarnowetarnow@avabiz.com2016-03-24T19:13:57Z2016-03-24T19:13:57Zhttp://cogprints.org/id/eprint/10089This item is in the repository with the URL: http://cogprints.org/id/eprint/100892016-03-24T19:13:57ZPreliminary Evidence: Diagnosed Alzheimer’s Disease But Not MCI Affects Working Memory Capacity: 0.7 of 2.7 Memory Slots is LostRecently it was shown explicitly that free recall consists of two stages: the first few recalls empty working memory (narrowly defined) and a second stage, a reactivation stage, concludes the recall (Tarnow, 2015; for a review of the theoretical predictions see Murdock, 1974). It was also shown that the serial position curve changes in mild Alzheimer’s disease – lowered total recall and lessened primacy - are similar to second stage recall and different from recall from working memory.
The Tarnow Unchunkable Test (TUT, Tarnow, 2013) uses double integer items to separate out only the first stage, the emptying of working memory, by making it difficult to reactivate items due to the lack of intra-item relationships.
Here it is shown that subject TUT selects out diagnosed Alzheimer’s Disease but not MCI. On average, diagnosed Alzheimer’s Disease is correlated with a loss of 0.7 memory slots (out of an average of 2.7 slots).
The identification of a lost memory slot may have implications for improved stage definitions of Alzheimer’s disease and for remediation therapy via working memory capacity management. In conjunction with the Alzheimer’s disease process map, it may also be useful to identify the exact location of working memory.
Eugen Tarnowetarnow@avabiz.com2014-08-24T21:07:30Z2015-04-20T11:40:47Zhttp://cogprints.org/id/eprint/9756This item is in the repository with the URL: http://cogprints.org/id/eprint/97562014-08-24T21:07:30ZCo-Variations among Cognition, Cerebellar
Disorders and Cortical Areas With
Regional Glucose-Metabolic Activities in a
Homogeneous Sample with Uner Tan Syndrome:
Holistic Functioning of the Human BrainPatients with Uner Tan syndrome (UTS) exhibit habitual quadrupedal locomotion (QL), intellectual disability, dysarthric speech and truncal ataxia. Examination of cognitive ability in this syndrome has not yet been demonstrated in the scientific literature. Aims: (i) To analyze the cognitive abilities of the siblings with UTS; (ii) to assess the grade of their ataxia in relation to cerebellar disorders; (iii) to measure the metabolic activities of various cerebral regions in comparison with healthy individuals; (iv) to detect the interrelationships among all of the measured variables (IQ test scores, ataxia scores, cerebro-cerebellar areas and their metabolic activity levels) to reveal the holistic activity of the
brain. The Minimental State Examination (MMSE) and Wechsler Adult Intelligence Scale (WAIS-R) were applied to the affected cases and healthy subjects. Cerebellar disorders were assessed by the International Cooperative Ataxia Rating Scale (ICARS). Brain MRI scans were performed and cerebro-cerebellar areas were measured on MRI scans, including their metabolic activities (SUV), measured by positron emission tomography (PET) scanning. MMSE and WAIS-R scores both correlated with cerebro-cerebellar areas. Cerebello-vermial areas and their metabolic activities were significantly smaller in patients than in normal controls; areas of the remaining structures were not significantly different between patients and healthy subjects. Brain areas significantly inter-correlated: ICARS negatively correlated with WAIS-R,MMSE scores, SUV, and cerebro-cerebellar areas, which significantly correlated with each other. The results suggested (i) ICARS may not only be a test for cerebellar disorders, but also may be related to global functioning of all of the
cerebro-cerebellar regions; (ii) ICARS, WAIS-R and MMSE may be measures of emergent properties of the holistic
activity of the brain; (iii) the psychomotor disorders in UTS may be related to decreased brain metabolism.Prof. Dr. Uner Tanunertan37@yahoo.com2017-02-18T20:31:39Z2017-02-18T20:31:39Zhttp://cogprints.org/id/eprint/9819This item is in the repository with the URL: http://cogprints.org/id/eprint/98192017-02-18T20:31:39ZAbilità linguistiche, extralinguistiche e paralinguistiche in pazienti con lesioni focali all’emisfero destroPazienti con lesioni focali all’emisfero destro (RHD), pur mostrando abilità linguistiche complessivamente preservate, riportano frequentemente una compromissione delle abilità comunicative (Cummings, 2009), che interessa in modo particolare la sfera pragmatica: deficit nelle abilità conversazionali (Lehman, 2006), nella comprensione di espressioni non letterali (Papagno et al., 2006), nel riconoscimento della prosodia (Pell, 2007) e delle espressioni facciali (Kucharska-Pietura et al., 2003).
La maggior parte degli studi (e.g Cheang & Pell, 2006; McDonald, 2000) ha valutato le competenze pragmatiche dei pazienti RHD attraverso il canale linguistico, mentre è stata meno studiata la componente gestuale (Brownell, 1999). La Teoria della Pragmatica Cognitiva (Bara, 2010), propone un modello unitario della comunicazione, in cui la competenza comunicativa è indipendente dal mezzo, linguistico o extralinguistico, utilizzato per veicolare significati; conferme a tale modello si ritrovano in studi su popolazioni cliniche (Gabbatore et al., 2014, Angeleri et al., 2008).
Cutica et al. (2006), in particolare, hanno studiato le abilità pragmatiche in comprensione con un campione di pazienti con lesioni all’emisfero destro e sinistro (LHD), evidenziando come i pazienti RHD, rispetto a quelli LHD, mostrassero deficit più gravi nella componente extralinguistica, a conferma di una specializzazione dell’emisfero destro nelle componenti extralinguistiche e paralinguistiche. Data la grande variabilità di profili associati ai deficit comunicativi nei pazienti RHD (Myers, 2005), è fondamentale l’utilizzo di strumenti di assessment che permettano una valutazione globale ed approfondita (Angeleri et al., 2012). Un assessment puntuale è inoltre necessario per impostare trattamenti riabilitativi mirati (e.g. Bosco et al., 2013).Alberto Parolaa.parola@unito.itDr Ilaria GabbatoreFederico CossaPatrizia GindriBruno G. BaraFrancesca M. BoscoKatiuscia Sacco2013-09-17T14:26:28Z2013-09-17T14:26:28Zhttp://cogprints.org/id/eprint/8982This item is in the repository with the URL: http://cogprints.org/id/eprint/89822013-09-17T14:26:28ZHuman quadrupedalism is not an epiphenomenon caused
by neurodevelopmental malformation and ataxiaTwo cases with quadrupedal locomotion (QL) were presented. In both cases, cognitive and psychiatric functions were normal and, no neurological deficits were observed, except for a sequel paralysis of left leg in Case 2. It was suggested that human QL (1) should not be considered as an epiphenomenon caused by neurodevelopmental malformation and
ataxia, but (2) may be considered as a re-emergence of the ancestral diagonal QL, and (3) it may spontaneously emerge in humans with entirely normal brains, by taking advantage
of neural networks such as central pattern generators that have been preserved for about 400 million years.Prof. Dr. Uner Tanunertan37@yahoo.com2013-05-04T23:25:03Z2013-05-04T23:25:03Zhttp://cogprints.org/id/eprint/8968This item is in the repository with the URL: http://cogprints.org/id/eprint/89682013-05-04T23:25:03ZDevelopment of bipedal and quadrupedal locomotion in humans from a dynamical systems perspective The first phase in the development 0f locomotion, pr,öary variability would occur in normal fetuses and infants, and those with Uner Tan syndrome. The neural networks for quadrupedal locomotion have apparently been transmitted epigenetically through many species since about 400 MYA.
The second phase is the neuronal selection process. During infancy, the most effective motor pattern(s) and their associated neuronal group(s) are selected through experience.
The third phase, secondary or adaptive variability, starts to bloom at two to three years of age and matures in adolescence. This third phase may last much longer in some patients with Uner Tan syndrome, with a considerably delay in selection of the well-balanced quadrupedal locomotion, which may emerge very late in adolescence in these cases. Prof. Dr. Uner Tanunertan37@yahoo.com2013-05-04T23:24:57Z2013-05-04T23:24:57Zhttp://cogprints.org/id/eprint/8967This item is in the repository with the URL: http://cogprints.org/id/eprint/89672013-05-04T23:24:57ZÜner Tan Syndrome: Review and Emergence of Human Quadrupedalism in Self-Organization,
Attractors and Evolutionary Perspectives
The first man reported in the world literature exhibiting habitual quadrupedal locomotion was discovered by a British traveler and writer on the famous Baghdat road near Havsa/Samsun on the middle Black-Sea coast of Turkey (Childs, 1917). Interestingly, no single case with human quadrupedalism was reported in the scientific literature after Child's first description in 1917 until the first report on the Uner Tan syndrome (UTS: quadrupedalism, mental retardation, and impaired speech or no speech)in 2005 (Tan, 2005, 2006). Between 2005 and 2010, 10 families exhibiting the syndrome were discovered in Turkey with 33 cases: 14 women (42.4%) and 19 men (57.6%). Including a few cases from other countries, there were 25 men (64.1%)and 14 women (35.9%). The number of men significantly exceeded the number of women (p < .05). Genetics alone did not seem to be informative for the origins of many syndromes, including the Uner Tan syndrome. From the viewpoint of dynamical systems theory, there may not be a single factor including the neural and/or genetic codes that predetermines the emergence of the human quadrupedalism.Rather, it may involve a self-organization process, consisting of many decentralized and local interactions among neuronal, genetic, and environmental subsystems. The most remarkable characteristic of the UTS, the diagonal-sequence quadrupedalism is well developed in primates. The evolutionarily advantage of this gait is not known. However, there seems to be an evolutionarily advantage of this type of locomotion for primate evolution, with regard to the emergence of complex neural circuits with related highly complex structures. Namely, only primates with diagonal-sequence quadrupedal locomotion followed an evolution favoring larger brains, highly developed cognitive abilities with hand skills, and language, with erect posture and bipedal locomotion, creating the unity of human being. It was suggested that UTS may be considered a further example for Darwinian diseases, which may be associated with an evolutionary understanding of the disorders using evolutionary principles, such as the natural selection. On the other hand, the human quadrupedalism was proposed to be a phenotypic example of evolution of reverse, i.e., the reacquisition by derived populations of the same character states as those of ancestor populations. It was also suggested that the emergence of the human quadrupedalism may be related to self-organizing processes occurring in complex systems, which select or attract one preferred behavioral state or locomotor trait out of many possible attractor states. Concerning the locomotor patterns, the dynamical systems in brain and body of the developing child may prefer some kind of locomotion, according to interactions of the internal components and the environmental conditions, without a direct role of any causative factor(s), such as genetic or neural codes, consistent with the concept of self-organization, suggesting no single element may have a causal priority. Prof. Dr. Uner Tanunertan37@yahoo.comProf. Dr. Yusuf TamamDr. Sibel Karacasibelemre2003@yahoo.comProf. Dr. Meliha TanMeliha_Tan@yahoo.com2011-10-27T01:35:28Z2011-10-27T01:35:28Zhttp://cogprints.org/id/eprint/7660This item is in the repository with the URL: http://cogprints.org/id/eprint/76602011-10-27T01:35:28ZInitial Free Recall Data Characterized and Explained By Activation Theory of Short Term MemoryThe initial recall distribution in a free recall experiment is shown to be predictably different from the overall free recall distribution including an offset which can cause the least remembered items to be almost completely absent from the first recall. Using the overall free recall distribution as input and a single parameter describing the probability of simultaneous reactivated items per number of items in the presented list, activation theory not only qualitatively but quantitatively describes the initial recall distributions of data by Murdock (1962) and Kahana et al (2002). That the initial free recall can be simply explained in terms of the overall recall suggests that theories of memory based on interference or other context sensitive information are false since knowledge of the future would have to be incorporated to predict the initial recall.Dr Eugen Tarnowetarnow@avabiz.com2011-05-02T15:54:46Z2011-05-02T15:54:46Zhttp://cogprints.org/id/eprint/7298This item is in the repository with the URL: http://cogprints.org/id/eprint/72982011-05-02T15:54:46ZThe very same thing: Extending the object token concept to incorporate causal constraints on individual identityThe contributions of feature recognition, object categorization, and recollection of episodic memories to the re-identification of a perceived object as the very same thing encountered in a previous perceptual episode are well understood in terms of both cognitive-behavioral phenomenology and neurofunctional implementation. Human beings do not, however, rely solely on features and context to re-identify individuals; in the presence of featural change and similarly-featured distractors, people routinely employ causal constraints to establish object identities. Based on available cognitive and neurofunctional data, the standard object-token based model of individual re-identification is extended to incorporate the construction of unobserved and hence fictive causal histories (FCHs) of observed objects by the pre-motor action planning system. Cognitive-behavioral and implementation-level predictions of this extended model and methods for testing them are outlined. It is suggested that functional deficits in the construction of FCHs are associated with clinical outcomes in both Autism Spectrum Disorders and later-stage stage Alzheimer's disease.
Chris Fieldsfieldsres@gmail.com2013-11-18T21:00:21Z2013-11-18T21:00:21Zhttp://cogprints.org/id/eprint/9124This item is in the repository with the URL: http://cogprints.org/id/eprint/91242013-11-18T21:00:21ZAutism’s direct cause? Failure of infant-mother eye contact in a complex adaptive system This paper shows that an experimental hypothesis is plausible and merits testing. In brief the hypothesis is that autism begins with a failure in early learning and that changing the environment of early learning would dramatically change its incidence. Strong statistical evidence supporting this hypothesis was published by Waldman et al. (2008) but this evidence has largely been ignored, perhaps because it challenges prevalent beliefs about autism.
This paper also suggests that the current epidemic of autism is serious enough, and intellectually mysterious enough, to merit attention from a wider community of cognitive scientists: new ideas are needed. A confirmation of this paper’s hypothesis would have interesting implications for cognitive science. Doctor Maxson J McDowellmaxmcdowell@jungny.com2011-09-17T17:45:46Z2012-05-18T14:25:37Zhttp://cogprints.org/id/eprint/7619This item is in the repository with the URL: http://cogprints.org/id/eprint/76192011-09-17T17:45:46ZDoes Visual Spatial Awareness Require the Visual Awareness of Space?Many philosophers have held that it is not possible to experience a spatial object, property, or relation except against the background of an intact awareness of a space that is somehow ‘absolute’. This paper challenges that claim, by analyzing in detail the case of a brain-damaged subject whose visual experiences seem to have violated this condition: spatial objects and properties were present in his visual experience, but space itself was not. I go on to suggest that phenomenological argumentation can give us a kind of evidence about the nature of the mind even if this evidence is not absolutely incorrigible.Dr. John Schwenklerschwenkler@msmary.edu2011-02-16T19:36:41Z2011-03-11T08:57:52Zhttp://cogprints.org/id/eprint/7220This item is in the repository with the URL: http://cogprints.org/id/eprint/72202011-02-16T19:36:41ZFrom “Oh, OK” to “Ah, yes” to “Aha!”: Hyper-systemizing and the rewards of insight
Hyper-systemizers are individuals displaying an unusually strong bias toward systemizing, i.e. toward explaining events and solving problems by appeal to mechanisms that do not involve intentions or agency. Hyper-systemizing in combination with deficit mentalizing ability typically presents clinically as an autistic spectrum disorder; however, the development of hyper-systemizing in combination with normal-range mentalizing ability is not well characterized. Based on a review and synthesis of clinical, observational, experimental, and neurofunctional studies, it is hypothesized that repeated episodes of insightful problem solving by systemizing result in attentional and motivational sensitization toward further systemizing via progressive and chronic deactivation of the default network. This hypothesis is distinguished from alternatives, and its correlational and causal implications are discussed. Predictions of the default-deactivation model accessible to survey-based instruments, standard cognitive measures and neurofunctional methods are outlined, and evidence pertaining to them considered.Chris Fieldsfieldsres@gmail.com2010-09-13T03:50:13Z2011-03-11T08:57:44Zhttp://cogprints.org/id/eprint/7022This item is in the repository with the URL: http://cogprints.org/id/eprint/70222010-09-13T03:50:13ZA New Theory of Consciousness: The Missing Link - OrganizationWhat is consciousness and what is the missing link between the sensory input and the cortical centre in the brain for consciousness? In the literature there are more than a million pages written about consciousness. The perspectives range from the field of metaphysics to those of quantum mechanics. However, no one today has produced a theory which is universally accepted. Consciousness is “something” which the majority of humans know that they posses, they use it when they want to understand their environment. However, no individual human knows whether other humans also posses consciousness. unless some tests such as she is looking at me, he is talking etc., are performed. We are caught in an intellectual sort of recursive carousel – we need consciousness to understand consciousness. To understand consciousness we have to understand the mechanism of its function, which is to effectively organize sensory inputs from our environment. Consciousness is the outcome of the process of organizing these sensory inputs. This implies that organization is an act which precedes consciousness. Since every activity in nature is to organize/disorganize, what is the element which compels this action? I am proposing that just like energy is the physical element that causes action, there is another physical element I have called it NASCIUM which has the capacity to cause organization. This is the missing link. Understanding the nature of organization, i.e. nascium, will enhance our capability to understand consciousness. A Tony De Lucatdeluca@inbox.comNewman L Stephensnstephe@ms.umanitoba.ca2010-09-13T03:57:52Z2011-03-11T08:57:40Zhttp://cogprints.org/id/eprint/6944This item is in the repository with the URL: http://cogprints.org/id/eprint/69442010-09-13T03:57:52ZTrajectory recognition as the basis for object individuation: A functional model of object file instantiation and object token encodingThe perception of persisting visual objects is mediated by transient intermediate representations, object files, that are instantiated in response to some, but not all, visual trajectories. The standard object file concept does not, however, provide a mechanism sufficient to account for all experimental data on visual object persistence, object tracking, and the ability to perceive spatially-disconnected stimuli as coherent objects. Based on relevant anatomical, functional, and developmental data, a functional model is developed that bases object individuation on the specific recognition of visual trajectories. This model is shown to account for a wide range of data, and to generate a variety of testable predictions. Individual variations of the model parameters are expected to generate distinct trajectory and object recognition abilities. Over-encoding of trajectory information in stored object tokens in early infancy, in particular, is expected to disrupt the ability to re-identify individuals across perceptual episodes, and lead to developmental outcomes with characteristics of autism spectrum disorders. Chris Fieldsfieldsres@gmail.com2010-10-18T11:00:45Z2011-03-11T08:57:45Zhttp://cogprints.org/id/eprint/7048This item is in the repository with the URL: http://cogprints.org/id/eprint/70482010-10-18T11:00:45ZOctologyThe manuscript describes a new sciencific discipline called Octology, which should unify morphogenetic linguistics and neurobiology to investigate the development of the words, cognition and behavior.Dr. Andrej Poleevandrejpoleev@yahoo.com2010-07-29T01:52:18Z2011-03-11T08:57:38Zhttp://cogprints.org/id/eprint/6876This item is in the repository with the URL: http://cogprints.org/id/eprint/68762010-07-29T01:52:18ZCognitive scienceThis is an encyclopedia entry and does not include an abstract.Valeria ManeraMaurizio Tirassamaurizio.tirassa@unito.it2010-09-13T03:59:01Z2011-03-11T08:57:40Zhttp://cogprints.org/id/eprint/6939This item is in the repository with the URL: http://cogprints.org/id/eprint/69392010-09-13T03:59:01ZUner Tan Syndrome: History, Clinical Evaluations, Genetics, and the
Dynamics of Human QuadrupedalismAbstract: This review includes for the first time a dynamical systems analysis of human quadrupedalism in Uner Tan syndrome, which is characterized by habitual quadrupedalism, impaired intelligence, and rudimentary speech. The first family was discovered in a small village near Iskenderun, and families were later found in Adana and two other small villages near Gaziantep and Canakkale. In all the affected individuals dynamic balance was impaired during upright walking,and they habitually preferred walking on all four extremities. MRI scans showed inferior cerebellovermian hypoplasia with slightly simplified cerebral gyri in three of the families, but appeared normal in the fourth. PET scans showed a decreased glucose metabolic activity in the cerebellum, vermis and, to a lesser extent the cerebral cortex, except for one patient,
whose MRI scan also appeared to be normal. All four families had consanguineous marriages in their pedigrees,
suggesting autosomal recessive transmission. The syndrome was genetically heterogeneous. Since the initial discoveries
more cases have been found, and these exhibit facultative quadrupedal locomotion, and in one case, late childhood onset. It has been suggested that the human quadrupedalism may, at least, be a phenotypic example of reverse evolution. From the viewpoint of dynamic systems theory, it was concluded there may not be a single factor that predetermines human quadrupedalism in Uner Tan syndrome, but that it may involve self-organization, brain plasticity, and rewiring, from the many decentralized and local interactions among neuronal, genetic, and environmental subsystems.Prof. Dr. Uner Tanunertan37@yahoo.com2009-12-22T00:41:00Z2011-03-11T08:57:33Zhttp://cogprints.org/id/eprint/6731This item is in the repository with the URL: http://cogprints.org/id/eprint/67312009-12-22T00:41:00ZMurdock free recall data: The initial recall search identifies the context by the location of the least remembered item and produces only better remembered items in proportion to the total recall difference.The curious free recall data of Murdock (1962) shows an additional surprise that seems to have gone undetected until now: the probability of guessing an item in the initial recall is not identical to the overall free recall curve. Initial recall of an item is well correlated with the total recall of that item using a straight line but with an unexpected offset. The offset varies with the presentation rate and the total number of list items but in each case it is the same as the total recall probability of the least recalled item. Thus for the initial “freest” of recalls the location of the least remembered item is identified, in effect identifying the context, and from there the items recalled are those better remembered items, in proportion to the probability of total recall. Within the tagging/retagging model (Tarnow, 2008, 2009) the free recall starts by an identification of a discontinuity in the activity level and produces an item with a probability according to the relative activity level.
I speculate that the activation level and its discontinuity is detected by glial cells assisting in rebuilding post-activation empty presynaptic neurotransmitter vesicles.Dr. Eugen Tarnowetarnow@avabiz.com2009-10-15T22:55:28Z2011-03-11T08:57:25Zhttp://cogprints.org/id/eprint/6629This item is in the repository with the URL: http://cogprints.org/id/eprint/66292009-10-15T22:55:28ZReentrant emergenceEmergent properties (EPs) are not causally reducible to the properties of a complex system’s elements. If a system’s properties cannot be reduced to those of any of its components, then that system is effectively a singular entity (SE). EPs are thus not properties of known complexes, but of SEs. A precise description of the parameters necessary to observe a physical system as an SE is thus necessary to establish under what conditions properties are understood as emergent. That description is provided in terms of the temporal dynamics of systems and their internal/external interactions. Dr. Steven Ravett Browndigiravett@mac.com2010-04-01T11:36:18Z2011-03-11T08:57:36Zhttp://cogprints.org/id/eprint/6817This item is in the repository with the URL: http://cogprints.org/id/eprint/68172010-04-01T11:36:18ZThe complexity of theory of mindThere is no abstract for this paper.Livia ColleFrancesca M. BoscoMaurizio Tirassamaurizio.tirassa@unito.it2010-04-01T11:36:29Z2011-03-11T08:57:36Zhttp://cogprints.org/id/eprint/6816This item is in the repository with the URL: http://cogprints.org/id/eprint/68162010-04-01T11:36:29ZTh.o.m.a.s.: An exploratory assessment of Theory of Mind in schizophrenic subjectsA large body of literature agrees that persons with schizophrenia suffer from a Theory of Mind (ToM) deficit. However, most empirical studies have focused on third-person, egocentric ToM, underestimating other facets of this complex cognitive skill. Aim of this research is to examine the ToM of schizophrenic persons considering its various aspects (first vs. second order, first vs. third person, egocentric vs. allocentric, beliefs vs. desires vs. positive emotions vs. negative emotions and how each of these mental state types may be dealt with), to determine whether some components are more impaired than others. We developed a Theory of Mind Assessment Scale (Th.o.m.a.s.) and administered it to 22 persons with a DSM-IV diagnosis of schizophrenia and a matching control group. Th.o.m.a.s. is a semi-structured interview which allows a multi-component measurement of ToM. Both groups were also administered a few existing ToM tasks and the schizophrenic subjects were administered the Positive and Negative Symptoms Scale and the WAIS-R. The schizophrenic persons performed worse than control at all the ToM measurements; however, these deficits appeared to be differently distributed among different components of ToM. Our conclusion is that ToM deficits are not unitary in schizophrenia, which also testifies to the importance of a complete and articulated investigation of ToM.Francesca M. BoscoLivia ColleSilvia De FazioAdele BonoSaverio RubertiMaurizio Tirassa2009-01-12T17:17:44Z2011-03-11T08:57:18Zhttp://cogprints.org/id/eprint/6317This item is in the repository with the URL: http://cogprints.org/id/eprint/63172009-01-12T17:17:44ZShort Term Memory May Be the Depletion of the Readily
Releasable Pool of Presynaptic Neurotransmitter VesiclesThe Tagging/Retagging model of short term memory was introduced earlier (1) to explain the linear relationship that exists between response time and correct response probability for word recall and recognition: At the initial stimulus presentation words tag the corresponding long term memory locations. The tagging process is linear in time and takes about one second to reach a tagging level of 100%. After stimulus presentation the tagging level decays logarithmically with time to 50% after 14 seconds and to 20% after 220 seconds. If a probe word is reintroduced the tagging level has to go back to 100% for the word to be properly identified, which leads to a delay in response time. This delay is proportional to the tagging loss which is in turn directly related to the decrease in probability of correct word recall and recognition.
Evidence suggests that the tagging level is the level of depletion of the Readily Releasable Pool (RRP) of neurotransmitter vesicles at presynaptic terminals. The evidence includes the initial linear relationship between tagging level and time as well as the subsequent logarithmic decay of the tagging level. The activation of a short term memory may thus be the depletion of RRP (exocytosis) and short term memory decay may be the ensuing recycling of the neurotransmitter vesicles (endocytosis).
Dr Eugen Tarnowetarnow@avabiz.com2009-01-05T23:59:36Z2011-03-11T08:57:17Zhttp://cogprints.org/id/eprint/6307This item is in the repository with the URL: http://cogprints.org/id/eprint/63072009-01-05T23:59:36ZShort Term Memory May Be the Depletion of the Readily Releasable Pool of Presynaptic Neurotransmitter Vesicles The Tagging/Retagging model of short term memory was introduced earlier (1) to explain the linear relationship that exists between response time and correct response probability for word recall and recognition: At the initial stimulus presentation words tag the corresponding long term memory locations. The tagging process is linear in time and takes about one second to reach a tagging level of 100%. After stimulus presentation the tagging level decays logarithmically with time to 50% after 14 seconds and to 20% after 220 seconds. If a probe word is reintroduced the tagging level has to go back to 100% for the word to be properly identified, which leads to a delay in response time. This delay is proportional to the tagging loss which is in turn directly related to the decrease in probability of correct word recall and recognition.
Evidence suggests that the tagging level is the level of depletion of the Readily Releasable Pool (RRP) of neurotransmitter vesicles at presynaptic terminals. The evidence includes the initial linear relationship between tagging level and time as well as the subsequent logarithmic decay of the tagging level. The activation of a short term memory may thus be the depletion of RRP (exocytosis) and short term memory decay may be the ensuing recycling of the neurotransmitter vesicles (endocytosis).
Dr Eugen Tarnowetarnow@avabiz.com2008-10-16T13:45:55Z2011-03-11T08:57:12Zhttp://cogprints.org/id/eprint/6232This item is in the repository with the URL: http://cogprints.org/id/eprint/62322008-10-16T13:45:55ZExperimental philosophy and the MBI
Various facets of the MBI are discussed, and how it can be used in connection with experimental philosophy, experimental psychology and neuroscience. Brief historical references are given. The large implications of the MBI with regards to McTaggart's paradox and the resolution of the difficulties with quantum mechanics is mentioned. Later sections deal with the mereological fallacy, multiple universes, teletransportation, mind cloning and mind splitting. Dreamwork is chosen as a prime example of the use of the MBI and recent work by Tononi and Baars is referred to.
Dr. John Yatesuvscience@gmail.com2008-08-30T23:20:48Z2011-03-11T08:57:10Zhttp://cogprints.org/id/eprint/6176This item is in the repository with the URL: http://cogprints.org/id/eprint/61762008-08-30T23:20:48ZCategory theory applied to a radically new but logically essential description of time and spaceMcTaggart's ideas on the unreality of time as expressed in "The Nature of Existence" have retained great interest for many years for scholars, academics and other philosophers. In this essay, there is a brief discussion which mentions some of the high points of this philosophical interest, and goes on to apply his ideas to modern physics and neuroscience. It does not discuss McTaggart's C and D series, but does emphasise how the use of derived versions of both his A and B series can be of great virtue in discussing both the abstract physics of time, and the present and future importance of McTaggart's ideas to the subject of time. Indeed an experiment using human volunteers and dynamic systems modelling which was carried out is described, which illustrates this fact. The Many Bubble Interpretation, which also derives from McTaggart's ideas, is discussed and various examples of its use and effectiveness are referred to. The Schrodinger Cat paradox is essentially resolved in principle, the quantum Zeno effect interpretable, Kwiat's recent result referred to, and the newly discovered reverse Stickgold effect described.
Dr. John Yatesuvcorr@gmail.com2007-10-22T10:40:15Z2011-03-11T08:56:59Zhttp://cogprints.org/id/eprint/5780This item is in the repository with the URL: http://cogprints.org/id/eprint/57802007-10-22T10:40:15ZEgocentric Spatial Representation in Action and PerceptionNeuropsychological findings used to motivate the “two visual systems” hypothesis have been taken to endanger a pair of widely accepted claims about spatial representation in visual experience. The first is the claim that visual experience represents 3-D space around the perceiver using an egocentric frame of reference. The second is the claim that there is a constitutive link between the spatial contents of visual experience and the perceiver’s bodily actions. In this paper, I carefully assess three main sources of evidence for the two visual systems hypothesis and argue that the best interpretation of the evidence is in fact consistent with both claims. I conclude with some brief remarks on the relation between visual consciousness and rational agency.Professor Robert Briscoerbriscoe@gmail.com2008-08-10T08:56:48Z2011-03-11T08:57:10Zhttp://cogprints.org/id/eprint/6159This item is in the repository with the URL: http://cogprints.org/id/eprint/61592008-08-10T08:56:48ZOn the nature and role of intersubjectivity in communicationWe outline a theory of human agency and communication and discuss the role that the capability to share (that is, intersubjectivity) plays in it. All the notions discussed are cast in a mentalistic and radically constructivist framework. We also introduce and discuss the relevant literature.Maurizio Tirassatirassa@psych.unito.itFrancesca M. Boscobosco@psych.unito.it2007-10-22T10:39:47Z2011-03-11T08:56:59Zhttp://cogprints.org/id/eprint/5781This item is in the repository with the URL: http://cogprints.org/id/eprint/57812007-10-22T10:39:47ZVision, Action, and Make-PerceiveIn this paper, I critically assess the enactive account of visual perception recently defended by Alva Noë (2004). I argue inter alia that the enactive account falsely identifies an object’s apparent shape with its 2D perspectival shape; that it mistakenly assimilates visual shape perception and volumetric object recognition; and that it seriously misrepresents the constitutive role of bodily action in visual awareness. I argue further that noticing an object’s perspectival shape involves a hybrid experience combining both perceptual and imaginative elements – an act of what I call ‘make-perceive.’Professor Robert Briscoerbriscoe@gmail.com2007-08-02Z2011-03-11T08:56:53Zhttp://cogprints.org/id/eprint/5607This item is in the repository with the URL: http://cogprints.org/id/eprint/56072007-08-02ZTHE PSYCHOMOTOR THEORY OF HUMAN MINDThis study presents a new theory to explain the neural origins of human mind. This is the psychomotor theory. The author briefly analyzed the historical development of the mind-brain theories. The close relations between psychological and motor systems were subjected to a rather detailed analysis, using psychiatric and neurological examples. The feedback circuits between mind, brain, and
body were shown to occur within the mind-brain-body triad, in normal states, and psycho-neural diseases. It was stated that psychiatric signs and symptoms are coupled with motor disturbances; neurological diseases are coupled with
psychological disturbances; changes in cortico-spinal motor-system activity may influence mind-brain-body triad, and vice versa. Accordingly, a psychomotor theory was created to explain the psychomotor coupling in health and disease, stating that, not themind-brain duality or unity, but themind-brain-body triad as a functional unit may be essential in health and disease, because mind does not end in the brain, but further controls movements, in a reciprocal manner; mental and motor events share the same neural substrate, cortical, and spinalmotoneurons;mental events emerging from the motoneuronal system expressed by the human language may be closely coupled with the unity of the mind-brain-body triad. So, the psychomotor theory
rejects the mind-brain duality and instead advances the unity of the psychomotor system, which will have important consequences in understanding and improving the human mind, brain, and body in health and disease.Prof. Dr. Uner TAN2007-07-28Z2011-03-11T08:56:55Zhttp://cogprints.org/id/eprint/5623This item is in the repository with the URL: http://cogprints.org/id/eprint/56232007-07-28ZDecision-Making: A Neuroeconomic PerspectiveThis article introduces and discusses from a philosophical point of view the nascent field of neuroeconomics, which is the study of neural mechanisms involved in decision-making and their economic significance. Following a survey of the ways in which decision-making is usually construed in philosophy, economics and psychology, I review many important findings in neuroeconomics to show that they suggest a revised picture of decision-making and ourselves as choosing agents. Finally, I outline a neuroeconomic account of irrationality. Benoit Hardy-Vallee2007-02-19Z2011-03-11T08:56:46Zhttp://cogprints.org/id/eprint/5395This item is in the repository with the URL: http://cogprints.org/id/eprint/53952007-02-19ZFlussi di coscienza di consapevolezza di inconsapevolezzaIn questo saggio si ipotizza una funzione cognitiva ai numerosi circuiti cortico/corticali e cortico/subcorticali, compresi i circuiti motori.
La funzione cognitiva è la seguente: Se…allora – ipotesi → movimento → verifica.
Tramite questa funzione la mente impara dall’esperienza.
La funzione cognitiva di tali circuiti è di natura attenzionale ripartita nelle componenti di passaggio, focalizzazione, mantenimento in presenza,.
Nel saggio si parla anche di flussi di informazione che corrono lungo i vari circuiti. Si distinguono tre tipologie di flussi: flussi di coscienza, flussi di consapevolezza, flussi di inconsapevolezza.
Questi ultimi si differenziano dagli altri due per il fatto che le informazioni trasmesse rimangono inconsce.
I primi due, al contrario, trasmettono informazioni di cui ci rendiamo conto.
Concetti e categorie sono flussi di inconsapevolezza.
Nel testo si dà anche una interpretazione delle correlazioni linguistiche, si mette in evidenza la differenza tra congiunzioni coordinative e subordinative. Inoltre si ipotizza l’origine attenzionale delle principali parti del discorso: sostantivi (aggettivi), verbi, preposizioni e congiunzioni.
Salvatore Leonardi2007-01-31Z2011-03-11T08:56:45Zhttp://cogprints.org/id/eprint/5380This item is in the repository with the URL: http://cogprints.org/id/eprint/53802007-01-31ZHOW TO SEPARATE CONCEPTUAL ISSUES FROM EMPIRICAL ONES IN THE STUDY OF CONSCIOUSNESSModern consciousness studies are in a healthy state, with many progressive empirical programmes in cognitive science, neuroscience and related sciences, using relatively conventional third-person research methods. However not all the problems of consciousness can be resolved in this way. These problems may be grouped into problems that require empirical advance, those that require theoretical advance, and those that require a re-examination of some of our pre-theoretical assumptions. I give examples of these, and focus on two problems—what consciousness is, and what consciousness does—that require all three. In this, careful attention to conscious phenomenology and finding an appropriate way to relate first-person evidence to third-person evidence appears to be central to progress. But we may also need to re-examine what we take to be “natural facts” about the world, and how we can know them. The same appears to be true for a trans-cultural understanding of consciousness that combines classical Indian phenomenological methods with the third-person methods of Western science.Prof Max Velmans2009-09-07T10:17:54Z2011-03-11T08:57:24Zhttp://cogprints.org/id/eprint/6606This item is in the repository with the URL: http://cogprints.org/id/eprint/66062009-09-07T10:17:54ZATTENTION SCORES AND ERP COMPONENTS IN
SENSOMOTOR TASKAttention as a psychological characteristic could be described with additional behavioural and electrophysiological parameters. The purpose of this work was to investigate the relationship between attention parameters (Attention test – Brickenkamp d2) – concentration performance, processing speed, rule compliance (accuracy) and the changes in various ERP components (indicating sensory and cognitive information processing) in healthy volunteers. EEG (Fz, Cz, Pz, C3’ and C4’) was recorded in two series. In the first series, without any task, the persons had to listen to low frequency (800 Hz) and higher frequency (1000 Hz) tones presented in randomized order. In the second task condition, they had to react to a low tone by pressing a button with the right hand and react to a high tone in the audio sequence by pressing a button with the left hand. ERPs were averaged for each series,
tone and electrode position. In the sensory-motor task series, we observed a relationship between parameters of the P3 component and the concentration performance attention parameter. We found a significantly shorter P3 latency and higher P3 amplitude in persons with higher concentration performance. As a whole, the obtained data showed that the attention processes concerning concentration performance could be related predominantly to the main cognitive and modality independent P3 component.Stiliyan Georgievstilliyan@gmail.comYordanka LalovaIvanka IvanovaDolja Philipovadolja@bio.bas.bg2006-12-03Z2011-03-11T08:56:42Zhttp://cogprints.org/id/eprint/5267This item is in the repository with the URL: http://cogprints.org/id/eprint/52672006-12-03ZNeuropsychological Generation of Source Amnesia: An Episodic Memory Disorder of the Frontal BrainSource amnesia is an explicit memory (declarative) disorder, particularly episodic, where source or contextual information concerning facts is severely distorted and/or unable to be recalled. This paper reviews the literature on source amnesia, including memory distrust syndrome, and its accepted correlation with the medial diencephalic system and the temporal lobes, and the suggested linkage between the frontal lobes, including special interest with the prefrontal cortex. Posthypnotic induction was the first presentation of source amnesia identified in the literature. The Wisconsin Cart Sorting Test (WCST), Positron Emission Topography (PET), Phonemic Verbal Fluency Test, Stroop Color Word Interference Test, and explicit and implicit memory tests are defined and linked to empirical research on amnesiacs.Shaheen Emmanuel Lakhanslakhan2006-10-05Z2011-03-11T08:56:35Zhttp://cogprints.org/id/eprint/5125This item is in the repository with the URL: http://cogprints.org/id/eprint/51252006-10-05ZThe primary function of REM sleepIn this paper, the physiological features associated with the different stages of REM sleep and with what information processing researchers have called “effort” and “arousal” are compared. It is suggested that tonic REM sleep and effort involve an increase in the metabolism of cerebral glycogen, and phasic REM sleep and arousal involve the transfer of glucose from the body to the brain. Both stages of REM sleep seem to elevate cerebral glucose levels and likely result in increased ATP generation in some part(s) of the brain. It is noted that the functioning of the hippocampus depends heavily on ATP, and that this part of the brain becomes especially active during REM sleep. From this, although many details remain to be clarified, it seems clear that the primary function of REM sleep is to re-energize the brain.Mr. Andrew E. Bernhard2006-07-23Z2011-03-11T08:56:32Zhttp://cogprints.org/id/eprint/5011This item is in the repository with the URL: http://cogprints.org/id/eprint/50112006-07-23ZEVIDENCE FOR "UNERTAN SYNDROME" AND THE EVOLUTION OF THE HUMAN MINDA new family exhibiting “Unertan Sydnrome” was discovered. The pedigree analysis showed marriages between relatives. This family was similar to the first one (see Tan, 2006a), providing a firm evidence for the new syndrome. The affected children showed habitual quadrupedal walking gait, that is, they walked on wrists and feet with straight legs and arms. Their heads and bodies were mildly flexed; they exhibited mild cerebellar signs, and severe mental retardation. The pedigree demonstrated a typical autosomal-recessive inheritance. The genetic nature of
this syndrome suggests a backward stage in human evolution (devolution), which would be consistent with theories of punctuated evolution. The results reflected a
new theory on the evolution of human beings. That is, the evolution of humans would in fact be the evolution of the extensor motor system, responsible for upright posture, against the gravitational forces. This would be coupled with the emergence of the human mind, which can be considered a reflexion of the human motor system, in accord with the psychomotor theory (see Tan, 2005a). The
most important characteristic of the newly emerged human mind was the resistance against gravitational forces. This was the resistive mind, the origins of human creativity.Prof. Dr. Uner Tan2006-04-08Z2011-03-11T08:56:23Zhttp://cogprints.org/id/eprint/4826This item is in the repository with the URL: http://cogprints.org/id/eprint/48262006-04-08ZI processi cognitiviIn questo saggio si ipotizza che i processi cognitivi della mente avvengono grazie ad un meccanismo di anticipazione temporale.
Questo meccanismo agisce sia a livello delle informazioni modali (forma, caldo/freddo, colore, amaro…) che dalle aree percettive primarie giungono nella corteccia temporale, sia a livello delle informazioni spaziali (posizione, stasi/movimento, grandezza) che dalle aree percettive giungono nella corteccia parietale.
Data una percezione, sulla base dell’esperienza pregressa la mente anticipa la “percezione” immediatamente successiva attivando movimenti adeguati a questa ipotesi.
L’anticipazione costituisce l’ipotesi, la percezione forma la verifica.
Attraverso il processo istante per istante di ipotesi/verifica, la mente impara a muovere il corpo, ad immaginare, a recuperare in memoria le conoscenze.
Anche i processi attenzionali di tipo cognitivo utilizzano questo meccanismo temporale di ipotesi/verifica
prof Salvatore Leonardi2008-03-10T14:56:39Z2011-03-11T08:57:05Zhttp://cogprints.org/id/eprint/5966This item is in the repository with the URL: http://cogprints.org/id/eprint/59662008-03-10T14:56:39ZBeing-in-the-world-with: Presence Meets Social And Cognitive Neuroscience In this chapter we will discuss the concepts of “presence” (Inner Presence) and “social presence” (Co-presence) within a cognitive and ecological perspective. Specifically, we claim that the concepts of “presence” and “social presence” are the possible links between self, action, communication and culture. In the first section we will provide a capsule view of Heidegger’s work by examining the two main features of the Heideggerian concept of “being”: spatiality and “being with”. We argue that different visions from social and cognitive sciences – Situated Cognition, Embodied Cognition, Enactive Approach, Situated Simulation, Covert Imitation - and discoveries from neuroscience – Mirror and Canonical Neurons - have many contact points with this view. In particular, these data suggest that our conceptual system dynamically produces contextualized representations (simulations) that support grounded action in different situations. This is allowed by a common coding – the motor code – shared by perception, action and concepts. This common coding also allows the subject for natively recognizing actions done by other selves within the phenomenological contents. In this picture we argue that the role of presence and social presence is to allow the process of self-identification through the separation between “self” and “other,” and between “internal” and “external”. Finally, implications of this position for communication and media studies are discussed by way of conclusion.Prof. G. Riva2006-10-09Z2011-03-11T08:56:39Zhttp://cogprints.org/id/eprint/5214This item is in the repository with the URL: http://cogprints.org/id/eprint/52142006-10-09ZRethinking the ontogeny of mindreading
We propose a mentalistic and nativist view of human early mental and social life and of the ontogeny of mindreading. We define the mental state of sharedness as the primitive, one-sided capability to take one's own mental states as mutually known to an i nteractant. We argue that this capability is an innate feature of the human mind, which the child uses to make a subjective sense of the world and of her actions. We argue that the child takes all of her mental states as shared with her caregivers. This a llows her to interact with her caregivers in a mentalistic way from the very beginning and provides the grounds on which the later maturation of mindreading will build. As the latter process occurs, the child begins to understand the mental world in terms of differences between the mental states of different agents; subjectively, this also corresponds to the birth of privateness.
ˇMaurizio TirassaFrancesca M. BoscoLivia Colle2006-10-09Z2011-03-11T08:56:39Zhttp://cogprints.org/id/eprint/5215This item is in the repository with the URL: http://cogprints.org/id/eprint/52152006-10-09ZSharedness and privateness in human early social life
This research is concerned with the innate predispositions underlying human intentional communication. Human communication is currently defined as a circular and overt attempt to modify a partner's mental states. This requires each party involved to posse ss the ability to represent and understand the other's mental states, a capability which is commonly referred to as mindreading, or theory of mind (ToM). The relevant experimental literature agrees that no such capability is to be found in the human speci es at least during the first year of life, and possibly later. This paper aims at advancing a solution to this theoretical problem. We propose to consider sharedness as the basis for intentional communication in the infant and to view it as a primitive, i nnate component of her cognitive architecture. Communication can then build upon the mental grounds that the infant takes as shared with her caregivers. We view this capability as a theory of mind in a weak sense.›Maurizio TirassaFrancesca M. BoscoLivia Colle2008-11-23T09:22:59Z2011-03-11T08:57:14Zhttp://cogprints.org/id/eprint/6267This item is in the repository with the URL: http://cogprints.org/id/eprint/62672008-11-23T09:22:59ZFrom deep dyslexia to agrammatic comprehension on silent readingWe report on a case of a French-speaking patient whose performance on reading aloud single words was characteristically deep dyslexic (in spite of preserved ability to identify letters), and whose comprehension on silent sentence reading was agrammatic and strikingly poorer than on oral reading. The first part of the study is mainly informative as regards (i) the relationship between letter identification, semantic paralexias and the ability to read nonwords, (ii) the differential character of silent and oral reading tasks, and (iii) the potential modality-dependent character of the deficits in comprehension encountered. In the second part of the study we examine the patient's sensitivity to verb-noun ambiguity and probe her skills in the comprehension of indexical structures by exploring her ability to cope with number agreement and temporal and prepositional relations. The results indicate the patient's sensitivity to certain dimensions of these linguistic categories, reveal a partly correct basis for certain incorrect responses, and, on the whole, favor a definition of the patient's disorders in terms of a deficit in integrating indexical information in language comprehension. More generally, the present study substantiates a microgenetic approach to neuropsychology, where the pathological behavior due to brain damage is described as an arrest of microgenesis at an early stage of development, so that patient's responses take the form of unfinished "products" which would normally undergo further development.Victor Rosenthalvictor.rosenthal@ehess.frMartine Dési2005-11-12Z2011-03-11T08:56:12Zhttp://cogprints.org/id/eprint/4589This item is in the repository with the URL: http://cogprints.org/id/eprint/45892005-11-12ZLe funzioni attenzionali e preattenzionaliIn questo scritto si ripartisce l’attività mentale in due funzioni di base. Si tratta della funzione preattenzionale e della funzione attenzionale.
La funzione preattenzionale è realizzata in modo involontario e non giunge alla coscienza. Essa riguarda le elaborazioni delle informazioni sensoriali che dai recettori sensoriali, passando attraverso le aree primarie, giungono nelle due aree associative: la corteccia parietale e la corteccia temporale.
La funzione attenzionale ha origine frontale e si espleta attraverso l’organizzazione spaziale (corteccia parietale) e temporale (corteccia temporale) della conoscenza.
prof Salvatore Leonardi2005-10-20Z2011-03-11T08:56:12Zhttp://cogprints.org/id/eprint/4586This item is in the repository with the URL: http://cogprints.org/id/eprint/45862005-10-20ZPercezione e movimentoIn questo saggio si propone una ipotesi di funzionamento mentale relativa ai sistemi percettivi ed al movimento. Si suppone che due circuiti attenzionali agiscono in sincronia per organizzare a livello spazio – temporale la conoscenza e gli atti motori.
Il primo di questi circuiti agisce sulle informazioni provenienti dai recettori sensoriali e si attiva con un processo botton-up; il secondo agisce sulla base delle informazioni depositate in memoria e si attiva secondo un processo top-down.
Il primo è di natura percettiva; il secondo di natura rappresentativa.
Il circuito rappresentativo anticipa, formulando ipotesi, quanto giungerà alla coscienza proveniente dall’esterno; il circuito percettivo conferma o smentisce l’ipotesi rappresentativa.
Il circuito rappresentativo elabora ciò che è in potenza, quello percettivo elabora ciò che è in atto.
prof Salvatore Leonardi2007-12-10T21:46:19Z2011-03-11T08:57:01Zhttp://cogprints.org/id/eprint/5857This item is in the repository with the URL: http://cogprints.org/id/eprint/58572007-12-10T21:46:19ZEnvironmental Sensitivity: A Neurobiological Phenomenon?Researchers often use the term “sensitivity ” when theorizing that certain persons may be more readily affected by various influences than others. Through a review of the literature, it is argued that some individuals are disposed toward a range of sensitivities that, in novelty as well as intensity, distinguish them from the general population. The author cites evidence indicating that such persons exhibit greater susceptibility to a range of environmental factors including allergies, migraine headache, chronic pain, and chronic fatigue. Their immediate family members appear to be similarly affected. Additionally, these “sensitive” individuals report a high degree of anomalous perception. While no single factor in a person’s background is likely to distinguish him/her as sensitive, eight demographic or personality factors are found to be significant. Michael Jawer2005-11-12Z2011-03-11T08:56:13Zhttp://cogprints.org/id/eprint/4601This item is in the repository with the URL: http://cogprints.org/id/eprint/46012005-11-12ZThe face, beauty, and symmetry: Perceiving asymmetry in beautiful facesThe relationship between bilateral facial symmetry and beauty remains to be clarified. Here, straight head-on photographs of “beautiful” faces from the collections of professional modeling agencies were selected. First, beauty ratings were obtained for these faces. Then, the authors created symmetrical left-left and right-right composites of the beautiful faces and asked a new group of subjects to choose the most attractive pair member. “Same” responses were allowed. No difference between the left-left and right-right composites was revealed but significant differences were obtained between “same” and the left-left or right-right. These results show that subjects detected asymmetry in beauty and suggest that very beautiful faces can be functionally asymmetrical.
Dr. Dahlia W. ZaidelJennifer A. Cohen2005-11-12Z2011-03-11T08:56:12Zhttp://cogprints.org/id/eprint/4590This item is in the repository with the URL: http://cogprints.org/id/eprint/45902005-11-12ZSeeing words that are not there: Detection biases in schizotypyObjective. The present studies introduced a novel word-detection paradigm to examine detection biases as a function of different schizotypy dimensions in a sample of undergraduate students.
Method. The participants (N = 80) were asked to detect fast moving (8 frames/sec) words among simultaneously moving non-words.
Results. Positive schizotypy was associated with a tendency to report words that never appeared in the trials. This effect was independent of task order, impulsivity and social desirability. None of the schizotypy measures was associated with correct words (detection accuracy).
Conclusions. It is inferred that a bias to report events in the absence of corresponding events may constitute a cross-modal mechanism responsible for translating internally generated experiences into perceptual experiences.
Tsakanikos EliasReed Phil2008-07-24T09:55:13Z2011-03-11T08:57:09Zhttp://cogprints.org/id/eprint/6146This item is in the repository with the URL: http://cogprints.org/id/eprint/61462008-07-24T09:55:13ZMicrowave Bioeffect Congruence with Schizophrenia The substantiation for microwave voice transmission development, which can be isolated to an individual, prompts review of the correlation between microwave bioeffects and schizophrenia. These correlations are extensive. Studies of both conditions report short-term and spatial memory deficit, time estimation changes, deficits in sequencing, coordination deficit, numerous electrophysiologic changes, startle decrease, neurotransmitter changes, hormone alterations, immune alterations, mitochondria deficits, lipid phosphorylation decrease, lipid peroxidation, deleterious histologic change in disease reduced brain areas, activation of hallucination involved brain areas, and ocular disease. Schizophrenia findings correlate with microwave bioeffects so extensively as to indicate a congruence, and appear to implicate a microwave involvement with enough patients to be remarkable in study results. The development of methods to exclude microwave means in psychosis is imperative, and research is proposed.
Mr. John J. McMurtrey2005-05-14Z2011-03-11T08:56:03Zhttp://cogprints.org/id/eprint/4349This item is in the repository with the URL: http://cogprints.org/id/eprint/43492005-05-14ZAppearance of symmetry, beauty, and health in human facesSymmetry is an important concept in biology, being related to mate selection strategies, health, and survival of species. In human faces, the relevance of left-right symmetry to attractiveness and health is not well understood. We compared the appearance of facial attractiveness, health, and symmetry in three separate experiments. Participants inspected front views of faces on the computer screen and judged them on a 5-point scale according to their attractiveness in Experiment 1, health in Experiment 2, and symmetry in Experiment 3. We found that symmetry and attractiveness were not strongly related in faces of women or men while health and symmetry were related. There was a significant difference between attractiveness and symmetry judgments but not between health and symmetry judgments. Moreover, there was a significant difference between attractiveness and health. Facial symmetry may be critical for the appearance of health but it does not seem to be critical for the appearance of attractiveness, not surprisingly perhaps because human faces together with the human brain have been shaped by adaptive evolution to be naturally asymmetrical.D. W. ZaidelS. M. AardeK. Baig2006-09-01Z2011-03-11T08:56:35Zhttp://cogprints.org/id/eprint/5104This item is in the repository with the URL: http://cogprints.org/id/eprint/51042006-09-01ZCategory deficits and paradoxical dissociations in Alzheimer's disease and Herpes Simplex HencephalitisMost studies examining category specificity are single-case studies of patients with living or non living deficits. Nevertheless, no explicit or agreed criteria exist for establishing category-specific deficits in single-cases regarding the type of analyses, whether to compare with healthy controls, the number of tasks, or the type of tasks. We examined to groups of patients with neurological pathology frequently accompained with impaired semantic memory (19 patients with Alzheimer disease and 15 with Herpes Simplex Encephalitis). Category knowledge was examined using three tasks (picture naming, naming-to-description and features verification). Both patients groups were compared with aged- and education- matched healthy controls. The profile of each patients was examined for consistency across tasks and across different analyses; however both prove to be inconsistent. One striking findings was the presence of a paradoxical dissociation ( i.e., patients who were impaired on living things on one task and non living things on another task). The findings have significant implication for how we determine category effects and, more generall for the methods use to document double dissociation across individual cases in this literature.Dr. Keith LawsProf. Giuseppe Sartori2005-06-19Z2011-03-11T08:56:04Zhttp://cogprints.org/id/eprint/4387This item is in the repository with the URL: http://cogprints.org/id/eprint/43872005-06-19ZCognitive Performance and Liver Function among Recently Abstinent Alcohol AbusersIt has frequently been suggested that some of the enduring subtle cognitive impairments seen in sober alcohol-dependent persons may be a result of sub-clinical liver dysfunction. Cognitive performance and liver function among 85 recently abstinent alcohol-dependent persons were assessed by means of a neuropsychological examination and the GGT test of liver function. Unlike some previous studies, no relationships were found between the two areas of functioning. It is argued that lack of statistical power did not account for the failure to find an association between the two domains. The proposition that residual cognitive impairment in abstinent alcoholic persons is (partly) mediated by earlier liver dysfunction rests on slight empirical foundations and remains speculative.Dr John F O'Mahony2005-12-19Z2011-03-11T08:56:14Zhttp://cogprints.org/id/eprint/4652This item is in the repository with the URL: http://cogprints.org/id/eprint/46522005-12-19ZEpilepsy – A Brief OverviewEpilepsy is a neurological condition in which an individual experiences chronic abnormal bursts of electrical discharge in the brain. These seizures can cause a variety symptoms depending on the areas of the brain affected. Symptoms can vary from mild to severe and can include complete or partial loss of consciousness, loss of speech, uncontrollable motor behavior, and/or unusual sensory experiences. From various studies worldwide6, approximately 0.5% of the population is reported to be affected by active epilepsy.Alain Koyama2006-09-25Z2011-03-11T08:56:36Zhttp://cogprints.org/id/eprint/5164This item is in the repository with the URL: http://cogprints.org/id/eprint/51642006-09-25ZEpilepsy – A Brief OverviewEpilepsy is a neurological condition in which an individual experiences chronic abnormal bursts of electrical discharge in the brain. These seizures can cause a variety symptoms depending on the areas of the brain affected. Symptoms can vary from mild to severe and can include complete or partial loss of consciousness, loss of speech, uncontrollable motor behavior, and/or unusual sensory experiences. From various studies worldwide6, approximately 0.5% of the population is reported to be affected by active epilepsy.Alain Koyama2005-12-19Z2011-03-11T08:56:14Zhttp://cogprints.org/id/eprint/4653This item is in the repository with the URL: http://cogprints.org/id/eprint/46532005-12-19ZA Review on the Cognitive Neuroscience of AutismWith increased recognition in the media, heightened prevalence, and advances in research technologies, investigation into the causes of autism has broadened in recent years. Studies at the molecular, structural, and behavioral levels have resulted in significant findings, linking autism to qualitative differences in neurological function and an alteration of early development. Familial aggregation of autism demonstrate a strong genetic factor, although genetics can not completely account for its pathogenesis. Studies show autism having one of the most complex pathologies among neurodevelopmental disorders. Future studies applying sophisticated methodologies in new areas may shed light on current mysteries surrounding the disorder.Alain Koyama2006-10-05Z2011-03-11T08:56:38Zhttp://cogprints.org/id/eprint/5208This item is in the repository with the URL: http://cogprints.org/id/eprint/52082006-10-05ZA Review on the Cognitive Neuroscience of AutismWith increased recognition in the media, heightened prevalence, and advances in research technologies, investigation into the causes of autism has broadened in recent years. Studies at the molecular, structural, and behavioral levels have resulted in significant findings, linking autism to qualitative differences in neurological function and an alteration of early development. Familial aggregation of autism demonstrate a strong genetic factor, although genetics can not completely account for its pathogenesis. Studies show autism having one of the most complex pathologies among neurodevelopmental disorders. Future studies applying sophisticated methodologies in new areas may shed light on current mysteries surrounding the disorder.Alain Koyama2006-10-09Z2011-03-11T08:56:39Zhttp://cogprints.org/id/eprint/5216This item is in the repository with the URL: http://cogprints.org/id/eprint/52162006-10-09ZA situated cognition perspective on presence
During interaction with computer-based 3-D simulations like virtual reality, users may experience a sense of involvement called presence. Presence is commonly defined as the subjective feeling of "being there". We discuss the state of the art in this inno vative research area and introduce a situated cognition perspective on presence. We argue that presence depends on the proper integration of aspects relevant to an agent's movement and perception, to her actions, and to her conception of the overall situ a tion in which she finds herself, as well as on how these aspects mesh with the possibilities for action afforded in the interaction with the artifact. We also aim at showing that studies of presence offer a test-bed for different theories of situated co gnition.›Antonella CarassaFrancesca MorgantiMaurizio Tirassa2004-01-13Z2011-03-11T08:55:27Zhttp://cogprints.org/id/eprint/3381This item is in the repository with the URL: http://cogprints.org/id/eprint/33812004-01-13ZVisuo-vestibular interaction in the reconstruction of travelled trajectoriesWe recently published a study of the reconstruction of passively travelled trajectories from optic flow. Perception was prone to illusions in a number of conditions, and not always veridical in the others. Part of the illusionary reconstructed trajectories could be explained by assuming that subjects base their reconstruction on the ego-motion percept built during the stimulus' initial moments
. In the current paper, we test this hypothesis using a novel paradigm: if the final reconstruction is governed by the initial percept, providing additional, extra-retinal information that modifies the initial percept should predictably alter the final reconstruction. The extra-retinal stimulus was tuned to supplement the information that was under-represented or ambiguous in the optic flow: the subjects were physically displaced or rotated at the onset of the visual stimulus. A highly asymmetric velocity profile (high acceleration, very low deceleration) was used. Subjects were required to guide an input device (in the form of a model vehicle; we measured position and orientation) along the perceived trajectory. We show for the first time that a vestibular stimulus of short duration can influence the perception of a much longer lasting visual stimulus. Perception of the ego-motion translation component in the visual stimulus was improved by a linear physical displacement: perception of the ego-motion rotation component by a physical rotation. This led to a more veridical reconstruction in some conditions, but to a less veridical reconstruction in other conditions.R.J.V. BertinA. Berthoz2006-04-29Z2011-03-11T08:55:00Zhttp://cogprints.org/id/eprint/2446This item is in the repository with the URL: http://cogprints.org/id/eprint/24462006-04-29ZBlending the Erotic and the Divine in Mystical LiteratureTHE BEGINNINGS OF SYMBOLIC-RELIGIOUS COGNITION -
Cognitive Archeology and Cognitive Fluidity: About 30,000 years ago (70,000 years after the fossil records of the anatomically modern human), religious thought and symbolic conceptual activity arose from the capacity of integrating specific-domain a process called "cognitive fluidity" (Mithen 1996).
Metaphor, Anthropomorphism and Cognitive Science: Metaphor is a basic mental capacity by which people understand themselves and the world around them through conceptual mappings of knowledge between mental spaces, using everyday knowledge to reason about more abstract concepts. Of all the templates for supernatural concepts, the ones that seriously matter to people are invariably person-like, because people are the most complex type of object that people know (Boyer 2001).
WHY GOD AS AN EROTIC LOVER? -
Diffusion and elaboration of religious memes: To reason about the ties between divine and human, man looks at his repertoire of human relationships, and the more significant ones are used to explain and speak of re-ligio. There are many metaphors used to represent the relationship between the divinity and the devotee (father/child, doctor/patient, teacher/pupil, etc.) The most significant relationship chosen by the mystic in terms of balance is Lover-Beloved.
Blending between God and Lover: The idealized conceptual models of the Divinity/beloved and of a devotee/lover began to blend through composition, completion and elaboration. The concept of human love relationship of these ancient cultures probably needs to be re-evaluated by modern students if it had become such an entrenched concept to be used as a source for a cognitive input space.
BLENDING THE EROTIC AND THE RELIGIOUS -
Examples of erotic religious texts and emergent structure: Sir hassirim, or Song of Songs (Judeo-Christian); Jayadeva’s Gita Govinda (Hindu); Rumi’s Mathanawi (Islam). Strongly erotic in content, these are part of the canons of the respective religious traditions, and so have deeply influenced subsequent elaboration of the erotic symbolism The lover (the faithful) and the Beloved (the Divinity) are usually on a par, and the domination of one is hardly ever present. Poetic descriptions include psychological states of jealousy, passion, separation and reunion, and ultimate union. The time of reunion is spring and the place is nature. What emerges is a relationship that not only unilaterally satisfies the material and spiritual needs of the religious person, but is reciprocal. In other words, the needs of both parties are fulfilled (devotee: food, explanations; god: praise, sacrifice). Moreover, due to the blend, an emotional need is also fulfilled. The dignity of the woman is finding her place in society, like the devotee finds his/her place in his/her creator’s creation, and so their relationship must be lived in the same natural setting. Because of the fusion between counterpart input spaces, there is a completion that humanizes the divinity so it becomes a he, the Man, motivated by the dominating role. However the elaboration of the blend tends to eliminate any domination in the relationship, as the needs of both sides are equal, and only when they are united do they feel completely realized. Their place is in nature, at
it’s most energetic and vibrant moment of springtime (ideally the time of life), and the time is eternal. Vito Evola2004-10-06Z2011-03-11T08:55:41Zhttp://cogprints.org/id/eprint/3817This item is in the repository with the URL: http://cogprints.org/id/eprint/38172004-10-06ZLess words, more words: psychometric schizotypy and verbal fluency
Positive and negative symptoms of schizophrenia have been differentially associated with irregularities in verbal production, suggesting the involvement of different underlying mechanisms in psychotic symptomatology. In view of that, the present investigation examined whether the amount of verbal production would be also differentially associated with negative and positive symptoms of psychometric schizotypy in a sample of college students (N=190). The participants were tested on a typical verbal fluency test and completed the O-LIFE schizotypy scales. The analyses revealed that decreased verbal fluency was associated with increased levels of negative schizotypy in participants who scored one standard deviation above the mean on the ‘Introvertive Anhedonia’ scale. In contrast, increased verbal fluency was associated with increased levels of positive schizotypy in participants who scored one standard deviation above the mean on the ‘Unusual Experiences’ scale. The obtained results are discussed in terms of the proposal that psychotic-like unusual experiences, like hallucinations, may be the product of a higher automatic spreading activation among stored lexical units, a mechanism which seems to account for the previously reported link between positive schizotypy and creativity. Dr Elias TsakanikosProfessor Gordon Claridge2005-04-21Z2011-03-11T08:55:59Zhttp://cogprints.org/id/eprint/4270This item is in the repository with the URL: http://cogprints.org/id/eprint/42702005-04-21ZLogical reasoning in schizotypal personalityIt was examined whether psychotic-like personality traits in a sample of 205 college students could predict logical reasoning deficits, akin to those seen in schizophrenia. The participants were tested on their ability to assess the logical validity of premises (Logical Reasoning Task), and completed a multi-dimensional schizotypy inventory (O-LIFE). Low accuracy was associated with increased levels of disorganized schizotypy (‘Cognitive Disorganization’), while elevated errors were associated with increased levels of positive (‘Unusual Experiences’), negative (‘Introvertive Anhedonia’) and impulsive (‘Impulsivity Non-conformity’) schizotypy. Nevertheless, multiple regression analyses revealed that negative schizotypy was retained as the only significant predictor after performance was corrected for random guessing, and the contribution of the average amount of time spent on each premise was controlled. The results suggest that, although most schizotypy dimensions have a detrimental effect on reasoning performance, possibly due to disadvantageous test-taking strategies, negative schizotypy is the most reliable predictor of logical reasoning deficits. It is proposed that social/interpersonal schizotypal traits, like negative symptoms of schizophrenia, are accompanied by deficient executive functions of working memory, which appear to undermine, inter alia, logical reasoning processing. Elias Tsakanikos2005-09-01Z2011-03-11T08:56:09Zhttp://cogprints.org/id/eprint/4524This item is in the repository with the URL: http://cogprints.org/id/eprint/45242005-09-01ZNeurobiology of dyslexia : A reinterpretation of the dataTheories of developmental dyslexia differ on how to best interpret the great variety of symptoms (linguistic, sensory, motor) observed in dyslexic individuals. One approach views dyslexia as a specific phonological deficit, which sometimes co-occurs with a more general sensorimotor syndrome. The present review of the neurobiology of dyslexia shows that neurobiological data are indeed consistent with this view, explaining both how a specific phonological deficit might arise, and why a sensorimotor syndrome should be significantly associated with it. This new conceptualisation of the aetiology of dyslexia may generalise to other neuro-developmental disorders, and may further explain heterogeneity within each disorder and co-morbidity between disorders.Franck Ramus2004-11-06Z2011-03-11T08:55:43Zhttp://cogprints.org/id/eprint/3928This item is in the repository with the URL: http://cogprints.org/id/eprint/39282004-11-06ZObjective measurement of simulator sickness and the role of visual-vestibular conflict situations: a study with vestibular-loss (a-reflexive) subjectsSimulators, in particular driving simulators, are gaining importance not only for research and development purposes, but also for education, training and even recreation. Progress in computer graphics and performance allow for highly realistic simulator visuals. High-end models are becoming somewhat better at generating acceptable inertial self-motion information, sometimes even providing real (but limited) linear translation in addition to angular movements. Simpler versions do not generate inertial information at all (fixed-base simulators). Here, we present a study on a problem that often occurs with driving simulators, i.e., simulator sickness. This phenomenon closely resembles the classically experienced motion sickness and can make a user abort a simulator run within minutes. We investigated the hypothesis that simulator sickness is caused by a visual-vestibular conflict, comparing susceptibility in normals and in vestibular-loss patients. We studied the psychophysical reactions of subjects, and quantitatively recorded their neurovegetative activity, to improve understanding of the underlying causes of simulator sickness, and to develop an objective measure for monitoring purposes. We used a fixed-base simulator, with an urban circuit with many sharp turns and traffic lights. No vestibular input was received during driving simulation, thus creating numerous visual-vestibular conflict situations. Subjects were asked to indicate continuously their discomfort on a visual-analog scale. We studied 33 normals (19 became sick) and 6 bilateral vestibular-loss subjects (one became truly sick, 2 others somewhat). Sickness correlated strongly with an increase in anxiety (Spielberger STAI). The subjective discomfort readings correlated well with simultaneous neurovegetative data and with a symptom scoring test administered immediately afterwards. There was no clear indication of an age or gender dependence in the normals. The fact that a complete vestibular-loss patient became sick indicates that more parameters may be responsible for simulator sickness than just a visuo-vestibular conflict situation (anxiety, nauseating odours, etc.). - Supported by the European Union (QLK6-CT-2002-00151: EUROKINESIS). Dr R.J.V. BertinDr A. GuillotDr C. ColletF. VienneDr S. EspiéDr W. Graf2004-09-03Z2011-03-11T08:55:40Zhttp://cogprints.org/id/eprint/3786This item is in the repository with the URL: http://cogprints.org/id/eprint/37862004-09-03ZSelf-awareness, self-recognition, and Theory of Mind: Conceptual distinctions and neuroanatomic localizationComment on Keenan's (2003) hypothesis that self-recognition, Theory-of-Mind, and self-awareness are located in the right hemisphere Alain Morin2004-11-29Z2011-03-11T08:55:44Zhttp://cogprints.org/id/eprint/3964This item is in the repository with the URL: http://cogprints.org/id/eprint/39642004-11-29ZSelf-directedness, integration and higher cognitionIn this paper I discuss connections between self-directedness, integration and higher cognition. I present a model of self-directedness as a basis for approaching higher cognition from a situated cognition perspective. According to this model increases in sensorimotor complexity create pressure for integrative higher order control and learning processes for acquiring information about the context in which action occurs. This generates complex articulated abstractive information processing, which forms the major basis for higher cognition. I present evidence that indicates that the same integrative characteristics found in lower cognitive process such as motor adaptation are present in a range of higher cognitive process, including conceptual learning. This account helps explain situated cognition phenomena in humans because the integrative processes by which the brain adapts to control interaction are relatively agnostic concerning the source of the structure participating in the process. Thus, from the perspective of the motor control system using a tool is not fundamentally different to simply controlling an arm.Dr Wayne D Christensen2004-01-17Z2011-03-11T08:55:27Zhttp://cogprints.org/id/eprint/3384This item is in the repository with the URL: http://cogprints.org/id/eprint/33842004-01-17ZWHY CONSCIOUS FREE WILL BOTH IS AND ISN’T AN ILLUSIONWegner’s analysis of the illusion of conscious will is close to my own account of how conscious experiences relate to brain processes. But our analyses differ somewhat on how conscious will is not an illusion. Wegner argues that once conscious will arises it enters causally into subsequent mental processing. I argue that while his causal story is accurate, it remains a first-person story. Conscious free will is not an illusion in the sense that this first-person story is compatible with and complementary to a third-person account of voluntary processing in the mind/brain. Prof Max Velmans2003-12-18Z2011-03-11T08:55:24Zhttp://cogprints.org/id/eprint/3319This item is in the repository with the URL: http://cogprints.org/id/eprint/33192003-12-18ZBrain-inspired conscious computing architectureWhat type of artificial systems will claim to be conscious and will claim to experience qualia? The ability to comment upon physical states of a brain-like dynamical system coupled with its environment seems to be sufficient to make claims. The flow of internal states in such system, guided and limited by associative memory, is similar to the stream of consciousness. Minimal requirements for an artificial system that will claim to be conscious were given in form of specific architecture named articon. Nonverbal discrimination of the working memory states of the articon gives it the ability to experience different qualities of internal states. Analysis of the inner state flows of such a system during typical behavioral process shows that qualia are inseparable from perception and action. The role of consciousness in learning of skills, when conscious information processing is replaced by subconscious, is elucidated. Arguments confirming that phenomenal experience is a result of cognitive processes are presented. Possible philosophical objections based on the Chinese room and other arguments are discussed, but they are insufficient to refute claims articon’s claims. Conditions for genuine understanding that go beyond the Turing test are presented. Articons may fulfill such conditions and in principle the structure of their experiences may be arbitrarily close to human.
Prof Wlodzislaw Duch2003-05-06Z2011-03-11T08:55:16Zhttp://cogprints.org/id/eprint/2923This item is in the repository with the URL: http://cogprints.org/id/eprint/29232003-05-06ZSolving the binding problem: cellular adhesive molecules and their control of the cortical quantum entangled networkQuantum entanglement is shown to be the only acceptable physical solution to the binding problem. The biological basis of interneuronal entanglement is described in the frames of the beta-neurexin-neuroligin model developed by Georgiev (2002) and is proposed novel mechanism for control of the neurons that are temporarily entangled to produce every single conscious moment experienced as present. The model provides psychiatrists with ‘deeper’ understanding of the functioning of the psyche in normal and pathologic conditions.Danko Georgiev2003-03-03Z2011-03-11T08:55:13Zhttp://cogprints.org/id/eprint/2813This item is in the repository with the URL: http://cogprints.org/id/eprint/28132003-03-03ZCIRCUITI ATTENZIONALIIn questo saggio si spiega la funzione dei circuiti attenzionali. Essi hanno una natura cinematica.Interagendo con le informazioni provenienti dai recettori sensoriali costruiscono gli oggetti fisici, i movimenti e le categorie.
I circuiti attenzionali sono costituiti da numerosissimi sottocircuiti e formano due fondamentali sistemi: 1)sistema operativo (si occupa di oggetti fisici emovimenti) 2) sistema semantico (si occupa dei significati)Salvatore Leonardi2003-03-14Z2011-03-11T08:55:14Zhttp://cogprints.org/id/eprint/2830This item is in the repository with the URL: http://cogprints.org/id/eprint/28302003-03-14ZOptic flow based perception of two-dimensional trajectories and the effects of a single landmark.It is well established that human observers can detect their heading direction on a very short time scale on the basis of optic flow. Can they also integrate these perceptions over time to reconstruct a 2D trajectory simulated by the optic flow stimulus? We investigated the visual perception and reconstruction of visually travelled two-dimensional trajectories from optic flow with and without a single landmark. Stimuli in which translation and yaw are unyoked can give rise to illusory percepts; using a structured visual environment instead of only dots can improve perception of these stimuli. Does the additional visual and/or extra-retinal information provided by a single landmark have a similar, beneficial effect? Here, seated, stationary subjects wore a head-mounted display showing optic flow stimuli that simulated various manoeuvres: linear or curvilinear 2D trajectories over a horizontal plane. The simulated orientation was either fixed in space, fixed relative to the path, or changed relative to both. Afterwards, subjects reproduced the perceived manoeuvre with a model vehicle, of which we recorded position and orientation. Yaw was perceived correctly. Perception of the travelled path was less accurate, but still good when the simulated orientation was fixed in space or relative to the trajectory. When the amount of yaw was not equal to the rotation of the path, or in the opposite direction, subjects still perceived orientation as fixed relative to the trajectory. This caused trajectory misperception because yaw was wrongly attributed to a rotation of the path. A single landmark could improve perception.R.J.V. BertinI. Israël2005-09-01Z2011-03-11T08:56:09Zhttp://cogprints.org/id/eprint/4522This item is in the repository with the URL: http://cogprints.org/id/eprint/45222005-09-01ZDevelopmental dyslexia: specific phonological deficit or general sensorimotor dysfunction?Dyslexia research is now facing an intriguing paradox: it is becoming increasingly clear that a significant proportion of dyslexics present sensory and motor deficits; however, as this “sensorimotor syndrome” is being studied in greater detail, it is also becoming increasingly clear that sensory and motor deficits will play only a limited role in a general causal explanation of specific reading disability.Dr Franck Ramus2003-09-04Z2011-03-11T08:55:20Zhttp://cogprints.org/id/eprint/3129This item is in the repository with the URL: http://cogprints.org/id/eprint/31292003-09-04ZFrontostriatal deficit in Motor Neuron Disease/Amyotrophic Lateral Sclerosis (MND/ALS)So far, cognitive derangements in MND/ALS have not been widely studied. Nevertheless, it seems that in subgroups of patients cognitive functions are impaired in different degree, so that often at least two sub-types of the syndrome are reported: Motor Neuron Disease/Amyotrophic Lateral Sclerosis/Dementia Syndrome (MND/ALS/DS) and Motor Neuron Disease/Amyotrophic Lateral Sclerosis/ Aphasia Syndrome (MND/ALS/AS. A third subtype showing both symptoms of cognitive impairment may be identified in subgroups of patients and denominated Motor Neuron Disease/Amyotrophic Lateral Sclerosis/Dementia-Aphasia Syndrome (MND/ALS/DAS).
Frontostriatal system is reported as a network heavily damaged in MND/ALS/DS, MND/ALS/AS, MND/ALS/DAS. The system is plausibly responsible of motor skills and verbs production, hence to become aware of a possible frontostriatal deficit in subgroup of MND/ALS patients might consent us to link at the brain level (motor) action and verbs and possibly ideomotor praxia and verbs.
We have used Goal-Oriented Perception Task (GOPT) and Action Fluency Task (AFT) in order to detect with some accuracy impairments related to gestaltic analysis directed toward a goal, and verb retrieval deficits possibly underlying executive system dysfunction that destabilizes the ability to mentally coordinate the information associated with a verb. These tests should consent to detect possible frontostriatal derangements.
We have tested 10 MND/ALS patients and 10 healthy subjects matched fore age, sex and laterality.
AFT showed that 3 out of 6 patients are heavily impaired in this test (6.3 (mean) verbs generated vs 13.3 of the control group). GOPT detected a remarkable impairment in all patients: p=0.0021 (grammatical side), p=0.0002 (perceptual side).
Reported frontostriatal deficit in MND/ALS seems confirmed by this study, and probably it is more easily detected by GOPT than by AFT.
Dr. G BuoianoDr. P BongioanniDr. M MagoniDr. MC CarbonciniDr. B Rossi2005-06-05Z2011-03-11T08:56:04Zhttp://cogprints.org/id/eprint/4375This item is in the repository with the URL: http://cogprints.org/id/eprint/43752005-06-05ZHemi-field memory for attractivenessIn order to determine whether or not facial attractiveness plays a role in hemispheric facial memory, 35 right-handed participants first assigned attractiveness ratings to faces and then performed a recognition test on those faces in the left visual half-field (LVF) and right visual half-field (RVF). We found significant interactions between the experimental factors and visual half- field. There were significant differences in the extreme ends of the rating scale, that is, the very unattractive versus the
very attractive faces: Female participants remembered very attractive faces of both women and men, with memory being superior in the RVF than in the LVF. In contrast,
the male participants remembered very unattractive faces of both women and men; RVF memory was better than the LVF for women faces while for men faces memory was superior in the LVF. The interactions with visual half-field suggest that hemispheric biases in remembering faces are influenced by degree of attractiveness.Choi DeblieckDahlia W. Zaidel2005-05-02Z2011-03-11T08:54:53Zhttp://cogprints.org/id/eprint/2068This item is in the repository with the URL: http://cogprints.org/id/eprint/20682005-05-02ZHow Dreams And Memory May Be Related I present a theory of dreams and long term memory structure that proposes that both entities are closely related. It is based on a variation of Freud's dream theory: (1) I re-label Freud's "Unconscious" the “Long Term Memory Structure” (LTMS), (2) I propose that dreams are ever present excitational responses to perturbations of perceptions and thought, during waking life as well as sleep, which only become conscious when the executive function of waking life ceases, and (3) I reinterpret Freud’s “Dream Work” as describing the pre-dream Storage Transformation of perceptions and thought into the LTMS. I make one further conjecture: Memories are stored in the LTMS according to what is already in the LTMS. The observables of Freud's theory remain the same. The new theory is also consistent with recent experimental findings and suggests a partial basis for personality: the selection process of the Storage Transformation. Dr. Eugen Tarnow2003-02-05Z2011-03-11T08:55:08Zhttp://cogprints.org/id/eprint/2756This item is in the repository with the URL: http://cogprints.org/id/eprint/27562003-02-05ZIS THE WORLD IN THE BRAIN, OR THE BRAIN IN THE WORLD?
(A commentary on Lehar, S. Gestalt isomorphism and the primacy of subjective conscious experience: A Gestalt Bubble model, Behavioral and Brain Sciences, in press)
Lehar provides useful insights into spatially extended phenomenology that may have major consequences for neuroscience. However, Lehar’s biological naturalism leads to counterintuitive conclusions and he does not give an accurate account of preceding and competing work. This commentary compares Lehar’s analysis with that of Velmans, which address similar issues but draws opposite conclusions. Lehar argues that the phenomenal world is in the brain, and concludes that the physical skull is beyond the phenomenal world. Velmans argues that the brain is in the phenomenal world and concludes that the physical skull is where it seems to be. Professor Max Velmans2003-02-25Z2011-03-11T08:55:13Zhttp://cogprints.org/id/eprint/2798This item is in the repository with the URL: http://cogprints.org/id/eprint/27982003-02-25ZIS THE WORLD IN THE BRAIN, OR THE BRAIN IN THE WORLD?
(A commentary on Lehar, S. Gestalt isomorphism and the primacy of subjective conscious experience: A Gestalt Bubble model, Behavioral and Brain Sciences, in press)
Lehar provides useful insights into spatially extended phenomenology that may have major consequences for neuroscience. However, Lehar’s biological naturalism leads to counterintuitive conclusions and he does not give an accurate account of preceding and competing work. This commentary compares Lehar’s analysis with that of Velmans, which address similar issues but draws opposite conclusions. Lehar argues that the phenomenal world is in the brain, and concludes that the physical skull is beyond the phenomenal world. Velmans argues that the brain is in the phenomenal world and concludes that the physical skull is where it seems to be. Professor Max Velmans2005-07-13Z2011-03-11T08:56:08Zhttp://cogprints.org/id/eprint/4463This item is in the repository with the URL: http://cogprints.org/id/eprint/44632005-07-13ZOn The Dynamic Timescale Of Mind-Brain InteractionIn neurophysiology it is widely assumed that our mind operates in millisecond timescale. This view might be wrong, because if consciousness is quantum coherent phenomenon at the level of protein assemblies, then its dynamic timescale can be picosecond one.Danko Georgiev2004-01-17Z2011-03-11T08:55:27Zhttp://cogprints.org/id/eprint/3382This item is in the repository with the URL: http://cogprints.org/id/eprint/33822004-01-17ZPRECONSCIOUS FREE WILL
This paper responds to continuing commentary on Velmans (2002a) “How could conscious experiences affect brains,” a target article for a special issue of JCS. I focus on the final question dealt with by the target article: how free will relates to preconscious and conscious mental processing, and I develop the case for preconscious free will. Although “preconscious free will” might appear to be a contradiction in terms, it is consistent with the scientific evidence and provides a parsimonious way to reconcile the commonsense view that voluntary acts are freely chosen with the evidence that conscious wishes and decisions are determined by preconscious processing in the mind/brain. I consider alternative interpretations of how “conscious free will” might operate by Libet and by Mangan and respond to doubts about the extent to which the operations of mind are revealed in consciousness, raised by Claxton and Bouratinos. In reconciling commonsense attributions of freedom and responsibility with the findings of science, preconscious free will can be shown to have practical consequences for adjudications in law. Prof Max Velmans2003-08-29Z2011-03-11T08:55:20Zhttp://cogprints.org/id/eprint/3125This item is in the repository with the URL: http://cogprints.org/id/eprint/31252003-08-29ZSubjective Perception of Time and a Progressive Present Moment: The Neurobiological Key to Unlocking ConsciousnessThe conclusion of physics, within both a historical and more recent context, that an objectively progressive time and present moment are derivative notions without actual physical foundation in nature, illustrate that these perceived chronological features originate from subjective conscious experience and the neurobiological processes underlying it. Using this conclusion as a stepping stone, it is posited that the phenomena of an in-built subjective conception of a progressive present moment in time and that of conscious awareness are actually one and the same thing, and as such, are also the outcome of the same neurobiological processes. A possible explanation as to how this might be achieved by the brain through employing the neuronal induced nonconscious cognitive manipulation of a small interval of time is proposed. The CIP phenomenon, elucidated within the context of this study is also then discussed.Peter Lynds2004-10-22Z2011-03-11T08:55:43Zhttp://cogprints.org/id/eprint/3901This item is in the repository with the URL: http://cogprints.org/id/eprint/39012004-10-22ZVisuo-spatial processing and dimensions of schizotypy: figure-ground segregation as a function of psychotic-like featuresThe aim of the reported study was to determine whether the ability to segregate a simple figure embedded in a complex visual ground, was associated with psychotic-like features in a sample of undergraduate students. The participants (N =100) were tested on the Hidden Figures Test, as well as the Raven’s Progressive Matrices, and completed a multi-dimensional schizotypy inventory (O–LIFE). The IQ scores were positively related to the number of correct responses on the Hidden Figures Test, but were unrelated to any of the schizotypy measures. Impaired Performance on the Hidden Figures Test was associated with negative schizotypy (‘Introvertive Anhedonia’), and enhanced performance was associated with the ‘Impulsive Non-Conformity’ scale. Performance on the Hidden Figures Test was independent of the positive (‘Unusual Experiences’), and the disorganized (‘Cognitive Disorganization’), schizotypy. The results are discussed in terms of a putative involvement of the frontal lobes in the negative symptomatology of schizophrenia, and in top-down (goal-driven) perceptual processing, as well as the possible compensatory functional aspect of impulsivity in terms of allocating attention. Elias TsakanikosReed Phil2003-03-19Z2011-03-11T08:55:14Zhttp://cogprints.org/id/eprint/2831This item is in the repository with the URL: http://cogprints.org/id/eprint/28312003-03-19ZVisuo-vestibular interaction in the reconstruction of travelled trajectoriesWe recently published a study of the reconstruction of passively travelled trajectories from optic flow. Perception was prone to illusions in a number of conditions, and not always veridical in the others. Part of the illusionary reconstructed trajectories could be explained by assuming that subjects base their reconstruction on the ego-motion percept built during the stimulus' initial moments
. In the current paper, we test this hypothesis using a novel paradigm: if the final reconstruction is governed by the initial percept, providing additional, extra-retinal information that modifies the initial percept should predictably alter the final reconstruction. The extra-retinal stimulus was tuned to supplement the information that was under-represented or ambiguous in the optic flow: the subjects were physically displaced or rotated at the onset of the visual stimulus. A highly asymmetric velocity profile (high acceleration, very low deceleration) was used. Subjects were required to guide an input device (in the form of a model vehicle; we measured position and orientation) along the perceived trajectory. We show for the first time that a vestibular stimulus of short duration can influence the perception of a much longer lasting visual stimulus. Perception of the ego-motion translation component in the visual stimulus was improved by a linear physical displacement: perception of the ego-motion rotation component by a physical rotation. This led to a more veridical reconstruction in some conditions, but to a less veridical reconstruction in other conditions.R.J.V. BertinA. Berthoz2003-01-31Z2011-03-11T08:55:08Zhttp://cogprints.org/id/eprint/2750This item is in the repository with the URL: http://cogprints.org/id/eprint/27502003-01-31ZHOW COULD CONSCIOUS EXPERIENCES AFFECT BRAINS?In everyday life we take it for granted that we have conscious control of some of our actions and that the part of us that exercises control is the conscious mind. Psychosomatic medicine also assumes that the conscious mind can affect body states, and this is supported by evidence that the use of imagery, hypnosis, biofeedback and other ‘mental interventions’ can be therapeutic in a variety of medical conditions. However, there is no accepted theory of mind/body interaction and this has had a detrimental effect on the acceptance of mental causation in science, philosophy and in many areas of clinical practice. Biomedical accounts typically translate the effects of mind into the effects of brain functioning, for example, explaining mind/body interactions in terms of the interconnections and reciprocal control of cortical, neuroendocrine, autonomic and immune systems. While such accounts are instructive, they are implicitly reductionist, and beg the question of how conscious experiences could have bodily effects. On the other hand, non-reductionist accounts have to cope with three problems: 1) The physical world appears causally closed, which would seem to leave no room for conscious intervention. 2) One is not conscious of one’s own brain/body processing, so how could there be conscious control of such processing? 3) Conscious experiences appear to come too late to causally affect the processes to which they most obviously relate. This paper suggests a way of understanding mental causation that resolves these problems. It also suggests that “conscious mental control” needs to be partly understood in terms of the voluntary operations of the preconscious mind, and that this allows an account of biological determinism that is compatible with experienced free will.
Professor Max Velmans2003-01-31Z2011-03-11T08:55:08Zhttp://cogprints.org/id/eprint/2751This item is in the repository with the URL: http://cogprints.org/id/eprint/27512003-01-31ZMAKING SENSE OF CAUSAL INTERACTIONS BETWEEN CONSCIOUSNESS AND BRAINMy target article (henceforth referred to as TA) presents evidence for causal interactions between consciousness and brain and some standard ways of accounting for this evidence in clinical practice and neuropsychological theory. I also point out some of the problems of understanding such causal interactions that are not addressed by standard explanations. Most of the residual problems have to do with how to cross the “explanatory gap” from consciousness to brain. I then list some of the reasons why the route across this gap suggested by physicalism won't work, in spite of its current popularity in consciousness studies. My own suggested route across the explanatory gap is more subterranean, where consciousness and brain can be seen to be dual aspects of a unifying, psychophysical mind. Some of the steps on this deeper route still have to be filled in by empirical research. But (as far as I can judge) there are no gaps that cannot be filled—just a different way of understanding consciousness, mind, brain and their causal interaction, with some interesting consequences for our understanding of free will. The commentaries on TA examined many aspects of my thesis viewed from both Western and Eastern perspectives. This reply focuses on how dual-aspect monism compares with currently popular alternatives such as “nonreductive physicalism”, clarifies my own approach, and reconsiders how well this addresses the “hard” problems of consciousness. We re-examine how conscious experiences relate to their physical/functional correlates and whether useful analogies can be drawn with other, physical relationships that appear to have dual-aspects. We also examine some fundamental differences between Western and Eastern thought about whether the existence of the physical world or the existence of consciousness can be taken for granted (with consequential differences about which of these is “hard” to understand). I then suggest a form of dual-aspect Reflexive Monism that might provide a path between these ancient intellectual traditions that is consistent with science and with common sense. Professor Max Velmans2002-05-04Z2011-03-11T08:54:55Zhttp://cogprints.org/id/eprint/2198This item is in the repository with the URL: http://cogprints.org/id/eprint/21982002-05-04ZPredictability of hand skill and cognitive abilities from craniofacial width in right- and left-handed men and women: relation of skeletal structure to cerebral functionRecently, a family of homeobox genes involved in brain and craniofacial development was identified. In light of this genetic background, we hypothesized that some functional characteristics of human brain (hand skill, cognition) may be linked to some structural characteristics of human skull (e.g. craniofacial width) in humans. Hand preference was assessed by the Oldfield`s Handedness Questionaire. Hand skill was measured by Peg Moving Task. Face width was measured from the anteroposterior cephalograms (X-ray) using right (R) and left (L) zygomatic points. Intelligence g was assessed by Cattell`s Culture Fair Intelligence Test; the perceptual-verbal ability was assessed by Finding A`s Test; the spatial ability was assessed by the mental rotation task, in right- and left-handed men and women. The percentages of right-, left-, and mixed-faced subjects were close to those found for paw preference in cats. So, Women tended to be more right-faced (R-L > 0) and less left-faced (R-L < 0) than men who were tended to be more left-faced and less right-faced than women. R-L face width inversely correlated with L-R PMT (peg moving time) in left-handers; there was a direct relation between these variables in right-handers. Cattell-IQ linearly increased with R-L face width in left-handers, negatively correlated in right-handed men and women. Verbal ability inversely related to R L face width in right- and left-handed men, but directly correlated in right-handed women. Number correct on mental rotation task positively linearly correlated with R-L face width in left-handers and right-handed women. It was concluded that the structural-functional coupling revealed in the present work may have its origins in parallel development of the craniofacial skeleton and brain under the influence of homeobox genes. Ertunc DayiMukadder OkuyanUner Tan2003-04-15Z2011-03-11T08:55:15Zhttp://cogprints.org/id/eprint/2872This item is in the repository with the URL: http://cogprints.org/id/eprint/28722003-04-15ZCOMPARISON OF EMOTIONAL RESPONSES IN MONKEYS WITH RHINAL CORTEX OR AMYGDALA LESIONSFour emotionally arousing stimuli were used to probe the behavior of monkeys with bilateral ablations of the entorhinal and perirhinal cortex. The animals’ behavioral changes were then contrasted with those observed earlier (Meunier et al., 1999) in monkeys with either neurotoxic or aspiration lesions of the neighboring amygdala. Rhinal cortex ablations yielded several subtle behavioral changes, but none of them resembled any of the disorders typically seen after amygdalectomies. The changes produced by rhinal damage took mainly the form of heightened defensiveness, and attenuated submission and approach responses, that is, just the opposite of some of the most distinctive symptoms following amygdala damage. These findings raise the possibility that the rhinal cortex and amygdala have distinct, interactive, functions in normal behavioral adaptation to affective stimuli.PhD Martine MeunierPhD Jocelyne Bachevalier2002-10-01Z2011-03-11T08:55:01Zhttp://cogprints.org/id/eprint/2489This item is in the repository with the URL: http://cogprints.org/id/eprint/24892002-10-01ZMicrogenesis, immediate experience and visual processes in readingThe concept of microgenesis refers to the development on a brief present-time scale of a percept, a thought, an object of imagination, or an expression. It defines the occurrence of immediate experience as dynamic unfolding and differentiation in which the ‘germ’ of the final experience is already embodied in the early stages of its development. Immediate experience typically concerns the focal experience of an object that is thematized as a ‘figure’ in the global field of consciousness; this can involve a percept, thought, object of imagination, or expression (verbal and/or gestural). Yet, whatever its modality or content, focal experience is postulated to develop and stabilize through dynamic differentiation and unfolding. Such a microgenetic description of immediate experience substantiates a phenomenological and genetic theory of cognition where any process of perception, thought, expression or imagination is primarily a process of genetic differentiation and development, rather than one of detection (of a stimulus array or information), transformation, and integration (of multiple primitive components) as theories of cognitivist kind have contended.
My purpose in this essay is to provide an overview of the main constructs of microgenetic theory, to outline its potential avenues of future development in the field of cognitive science, and to illustrate an application of the theory to research, using visual processes in reading as an example. Victor Rosenthal2004-07-13Z2011-03-11T08:55:38Zhttp://cogprints.org/id/eprint/3716This item is in the repository with the URL: http://cogprints.org/id/eprint/37162004-07-13ZNormal mere exposure effect with impaired recognition in Alzheimer’s disease.We investigated the mere exposure effect and the explicit memory in Alzheimer’s disease (AD) patients and elderly control subjects, using unfamiliar faces. During the exposure phase, the subjects estimated the age of briefly flashed faces. The mere exposure effect was examined by presenting pairs of faces (old and new) and asking participants to select the face they liked. The participants were then presented with a forced-choice explicit recognition task. Controls subjects exhibited above-chance preference and recognition scores for old faces. The AD patients also showed the mere exposure effect but no explicit recognition. These results suggest that the processes involved in the mere exposure effect are preserved in AD patients despite their impaired explicit recognition. The results are discussed in terms of Seamon et al.’s proposal (1995) that processes involved in the mere exposure effect are equivalent to those subserving perceptual priming. These processes would depend on extrastriate areas which are relatively preserved in AD patients. A AdamS WillemsM Van der Linden2004-01-20Z2011-03-11T08:55:27Zhttp://cogprints.org/id/eprint/3400This item is in the repository with the URL: http://cogprints.org/id/eprint/34002004-01-20ZOrienting of attention in left unilateral neglectAfter right posterior brain damage, patients may ignore events occurring on their left, a condition known as unilateral neglect. Although deficits at different levels of impairment may be at work in different patients, the frequency and severity of attentional problems in neglect patients have been repeatedly underlined. Recent advances in the knowledge of the mechanisms of spatial attention in normals may help characterizing these deficits. The present review focuses on studies exploring several aspect of attentional processing in unilateral neglect, with particular reference to the dichotomy between 'exogenous', or stimulus-related, and 'endogenous', or strategy-driven, orienting of attention. A large amount of neuropsychological evidence suggests that a basic mechanism leading to left neglect behavior is an impaired exogenous orienting toward left-sided targets. In contrast, endogenous processes seem to be relatively preserved, if slowed, in left unilateral neglect. Other component deficits, such as a general slowing of the operations of spatial attention, might contribute to neglect behavior. These results are presented and discussed, and their implications for hemispheric specialization in attentional orienting and for the mechanisms of visual consciousness are explored.P. BartolomeoS. Chokron2002-07-25Z2011-03-11T08:54:57Zhttp://cogprints.org/id/eprint/2349This item is in the repository with the URL: http://cogprints.org/id/eprint/23492002-07-25ZThe relationship between motor control and phonology in dyslexic childrenBackground: The goal of this study was to investigate the automaticity/cerebellar theory of dyslexia. We tested phonological skills and cerebellar function in a group of dyslexic 8-12 year old children and their matched controls. Tests administered included the Phonological Assessment Battery, postural stability, bead threading, finger to thumb and time estimation.
Results: Dyslexic children were found to be significantly poorer than the controls at all tasks but time estimation. About 75% of dyslexics were more than one standard deviation below controls in phonological ability, and 50% were similarly impaired in motor skills. However, at least part of the discrepancy in motor skills was due to dyslexic individuals who had additional disorders (ADHD and/or DCD). The absence of evidence for a time estimation deficit also casts doubt on the cerebellar origin of the motor deficiency. About half the dyslexic children didn't have any motor problem, and there was no evidence for a causal relationship between motor skills on the one hand and phonological and reading skills on the other.
Conclusion: This study provides partial support for the presence of motor problems in dyslexic children, but does not support the hypothesis that a cerebellar dysfunction is the cause of their phonological and reading impairment. Franck RamusElizabeth PidgeonUta Frith2004-09-03Z2011-03-11T08:55:40Zhttp://cogprints.org/id/eprint/3790This item is in the repository with the URL: http://cogprints.org/id/eprint/37902004-09-03ZRight hemispheric self-awareness: A critical assessmentIn this commentaryI evaluate the claim made byKeenan, Nelson, OConnor, and
Pascual-Leone (2001) that since self-recognition results from right hemispheric activity,
self-awareness too is likely to be produced by the activity of the same hemisphere.
This reasoning is based on the assumption that self-recognition represents a
valid operationalization of self-awareness; I present two views that challenge this
rationale. Keenan et al. also support their claim with published evidence relating
brain activityand self-awareness; I closely examine their analysis of one specific
review of literature and conclude that it appears to be biased. Finally, recent research
suggests that inner speech (which is associated with left hemispheric activity) is
linked to self-awareness—an observation that further casts doubt on the existence of
a right hemispheric self-awareness.Alain Morin2003-04-15Z2011-03-11T08:55:15Zhttp://cogprints.org/id/eprint/2885This item is in the repository with the URL: http://cogprints.org/id/eprint/28852003-04-15ZShamanism and cognitive evolution [Commentary on Michael Winkelman].NoneNicholas Humphrey2002-07-26Z2011-03-11T08:54:57Zhttp://cogprints.org/id/eprint/2350This item is in the repository with the URL: http://cogprints.org/id/eprint/23502002-07-26ZTheories of developmental dyslexia: Insights from a multiple case study of dyslexic adults
A multiple case study was conducted in order to assess three leading theories of developmental dyslexia: the phonological, the magnocellular (auditory and visual) and the cerebellar theories. Sixteen dyslexic and 16 control university students were administered a full battery of psychometric, phonological, auditory, visual and cerebellar tests. Individual data reveal that all 16 dyslexics suffer from a phonological deficit, 10 from an auditory deficit, 4 from a motor deficit, and 2 from a visual magnocellular deficit. Results suggest that a phonological deficit can appear in the absence of any other sensory or motor disorder, and is sufficient to cause a literacy impairment, as demonstrated by 5 of the dyslexics. Auditory disorders, when present, aggravate the phonological deficit, hence the literacy impairment. However, auditory deficits cannot be characterised simply as rapid auditory processing problems, as would be predicted by the magnocellular theory. Nor are they restricted to speech. Contrary to the cerebellar theory, we find little support for the notion that motor impairments, when found, have a cerebellar origin, or reflect an automaticity deficit. Overall, the present data support the phonological theory of dyslexia, while acknowledging the presence of additional sensory and motor disorders in certain individuals.Franck RamusStuart RosenSteven C. DakinBrian L. DayJuan M. CastelloteSarah WhiteUta Frith2001-11-05Z2011-03-11T08:54:48Zhttp://cogprints.org/id/eprint/1850This item is in the repository with the URL: http://cogprints.org/id/eprint/18502001-11-05ZIl cervello e le sue funzioniIn questo saggio viene proposta una nuova teoria sul funzionamento del cervello. Partendo dalla visione e facendo riferimento a semplici principi di carattere generale si cerca di chiarire la percezione e le patologie ad essa connesse.Salvatore Leonardi2012-11-09T19:34:57Z2012-11-09T19:34:57Zhttp://cogprints.org/id/eprint/8082This item is in the repository with the URL: http://cogprints.org/id/eprint/80822012-11-09T19:34:57ZDopaminergic Regulation of Neuronal Circuits in Prefrontal CortexNeuromodulators, like dopamine, have considerable influence on the
processing capabilities of neural networks.
This has for instance been shown in the working memory functions
of prefrontal cortex, which may be regulated by altering the
dopamine level. Experimental work provides evidence on the biochemical
and electrophysiological actions of dopamine receptors, but there are few
theories concerning their significance for computational properties
(ServanPrintzCohen90,Hasselmo94).
We point to experimental data on neuromodulatory regulation of
temporal properties of excitatory neurons and depolarization of inhibitory
neurons, and suggest computational models employing these effects.
Changes in membrane potential may be modelled by the firing threshold,
and temporal properties by a parameterization of neuronal responsiveness
according to the preceding spike interval.
We apply these concepts to two examples using spiking neural networks.
In the first case, there is a change in the input synchronization of
neuronal groups, which leads to
changes in the formation of synchronized neuronal ensembles.
In the second case, the threshold
of interneurons influences lateral inhibition, and the switch from a
winner-take-all network to a parallel feedforward mode of processing.
Both concepts are interesting for the modeling of cognitive functions and may
have explanatory power for behavioral changes associated with dopamine
regulation.Gabriele Schelergscheler@gmail.com2004-01-10Z2011-03-11T08:54:45Zhttp://cogprints.org/id/eprint/1715This item is in the repository with the URL: http://cogprints.org/id/eprint/17152004-01-10ZFunctional asymmetry in the human face: Perception of health in the left and right sides of the faceThe expression of health on the human face, like beauty or emotions, is an important biological display. Previous findings of left-right functional asymmetry in facial attractiveness and the linkage of attractiveness and health in evolutionary biology notions have prompted the present study. A total of 38 pairs of left-left and right-right facial composites were viewed by 24 subjects on a computer screen, and the task was to decide which member of the pair looked healthier or there was no difference. The results revealed a significant interactions between face side and sex of face. Right-right composites of women's faces were judged significantly healthier than left-left, whereas in men's faces, no significant left-right difference emerged. As these results parallel previous findings of attractiveness in the identical set of faces, we propose that evolutionary biology notions linking the appearance of health and of attractiveness apply to the human face as well.Veronica A. ReisDahlia W. Zaidel2001-07-29Z2011-03-11T08:54:45Zhttp://cogprints.org/id/eprint/1718This item is in the repository with the URL: http://cogprints.org/id/eprint/17182001-07-29ZHemispheric effects of canonical views of category members with known typicality levelsIs there a preferred hemispheric canonical view of a visual concept? We investigated this question in a natural superordinate category membership decision task using a hemi-field paradigm. Participants had to decide whether or not an image of an object lateralized in the left (LVF) or right (RVF) visual half field is a member of a predesignated superordinate category. The objects represented high, medium, or low typicality levels, and each object had 6 different perspective views (front, front-right, front-left, side, back-left, and back-right). The latency responses revealed a significant interaction of Hemi Field X View X Typicality (there was no hemi-field difference in accuracy). The findings confirm the presence of asymmetry in stored concepts in long-term memory and suggest, in addition, a hemispheric canonical view of these concepts, a view strongly related to typicality level.D. W. ZaidelA. Kosta2002-11-19Z2011-03-11T08:55:06Zhttp://cogprints.org/id/eprint/2613This item is in the repository with the URL: http://cogprints.org/id/eprint/26132002-11-19ZImitation, mirror neurons and autismVarious deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show activity in relation both to specific actions performed by self and matching actions performed by others, providing a potential bridge between minds. MN systems exist in primates without imitative and ‘theory of mind’ abilities and we suggest that in order for them to have become utilized to perform social cognitive functions, sophisticated cortical neuronal systems have evolved in which MNs function as key elements. Early developmental failures of MN systems are likely to result in a consequent cascade of developmental impairments characterised by the clinical syndrome of autism.Justin H.G. WilliamsAndrew WhitenThomas SuddendorfDavid I. Perrett2001-06-02Z2011-03-11T08:54:39Zhttp://cogprints.org/id/eprint/1536This item is in the repository with the URL: http://cogprints.org/id/eprint/15362001-06-02ZLosing the error related negativity (ERN): an indicator for willed actionWhen people make errors in a discrimination task, a negative-going waveform can be observed in scalp-recorded EEG that has been coined the error-related negativity (ERN). We hypothesized that the ERN only occurs with slips, that is unwilled action errors, but not if an error is committed willingly and intentionally. We investigated the occurrence of the ERN in a choice reaction time task that has been shown to produce an ERN and in an error simulation task where subjects had to fake errors while the EEG was recorded. We observed a loss of the ERN when errors were committed in willed actions but not in unwilled actions thus supporting the idea that the production of the ERN is tied to slips in unwilled actions but not mistakes in willed actions. Brigitte StemmerWolfgang WitzkePaul Walter Schoenle2010-04-01T11:36:48Z2011-03-11T08:57:35Zhttp://cogprints.org/id/eprint/6813This item is in the repository with the URL: http://cogprints.org/id/eprint/68132010-04-01T11:36:48ZNeuropragmatics: Extralinguistic communication after closed head injuryThis work is concerned with the decay of communicative abilities after head trauma. A protocol composed of 16 videotaped scenes was devised in order to investigate the comprehension of several types of communicative actions realized with extralinguistic means, like pointing or clapping. The protocol was administered to 30 closed head injured individuals. The results showed a decreasing performance from simple standard acts, to complex standard acts, deceits, and ironies. The subjects' performance was worse with the scenes reproducing failing, rather than successful, communicative actions. The results are compared with those we previously obtained with a linguistic protocol. A theory of the cognitive processes underlying intentional communication is outlined and used to explain the results.Bruno G. BaraIlaria CuticaMaurizio Tirassamaurizio.tirassa@unito.it2002-01-11Z2011-03-11T08:54:52Zhttp://cogprints.org/id/eprint/2015This item is in the repository with the URL: http://cogprints.org/id/eprint/20152002-01-11ZNeuropsychological indicators of heteromodal cortex (dys)function relevant to conditioned blocking measures of attention in schizophreniaBackground.
Learning a predictive relationship between two events can block learning about an added event (conditioned blocking, CB). Patients with nonparanoid schizophrenia can show reduced CB and learn about the similar consequences of the added event. What parts of the brain are involved in the functions required in learning the CB task and actually showing 'blocking' - a part of normal selective attention processes? As a first approximation, we ask if neuropsychological test performance sensitive to specific cortical regions is associated with these two functions.
Methods.
This study reports on the relationship of associative learning and CB measures of attention obtained with a visuospatial maze-like task to signs of heteromodal cortex function provided by performance on a battery of 10 neuropsychological tasks. These tasks were sensitive to frontal, parietal and temporal lobe function of the left and right hemisphere. Acquisition criteria for the task were achieved by 62 patients with schizophrenia and 62 matched controls but not by 39 other people with schizophrenia.
Results.
First right-hemisphere, visuo-spatial abilities were generally associated with faster task-learning (e.g. visual reproduction, immediate and delayed, picture-completion), and patients that could not learn the task were poorer on tests emphasising set-switching and problem-solving abilities associated with left frontal lobe function (e.g. trail-making, block-design).
Second CB expression depended on Stroop- and Mooney-faces-task performance that are reported to require cingulate and parietal lobe function.
Conclusions.
As would be predicted right hemisphere function was implicated in performing a visuospatial learning task. The additional CB requirement incurred additional anterior cingulate and right parietal involvement. Functionally this probably reflected effortful attentional processes, and illustrates the problems of patients with schizophrenia in switching between automatic and controlled processing strategies. The results are astonishingly consistent with imaging studies implicating brain regions such as the cingulate and intra-parietal sulcus in attention (Mesulam, 1999).
R.D. Oades Bender Müller Sartory2002-03-08Z2011-03-11T08:54:54Zhttp://cogprints.org/id/eprint/2121This item is in the repository with the URL: http://cogprints.org/id/eprint/21212002-03-08ZOptic flow based perception of two-dimensional trajectories and the effects of a single landmark.It is well established that human observers can detect their heading direction on a very short time scale on the basis of optic flow (500ms; Hooge et al., 2000). Can they also integrate these perceptions over time to reconstruct a 2D trajectory simulated by the optic flow stimulus? We investigated the visual perception and reconstruction of passively travelled two-dimensional trajectories from optic flow with and without a single landmark. Stimuli in which translation and yaw are unyoked can give rise to illusory percepts; using a structured visual environment instead of only dots can improve perception of these stimuli. Does the additional visual and/or extra-retinal information provided by a single landmark have a similar, beneficial effect? Here, seated, stationary subjects wore a head-mounted display showing optic flow stimuli that simulated various manoeuvres: linear or curvilinear 2D trajectories over a horizontal ground plane. The simulated orientation was either fixed in space, fixed relative to the path, or changed relative to both. Afterwards, subjects reproduced the perceived manoeuvre with a model vehicle, of which we recorded position and orientation. Yaw was perceived correctly. Perception of the travelled path was less accurate, but still good when the simulated orientation was fixed in space or relative to the trajectory. When the amount of yaw was not equal to the rotation of the path, or in the opposite direction, subjects still perceived orientation as fixed relative to the trajectory. This caused trajectory misperception because yaw was wrongly attributed to a rotation of the path. A single landmark could improve perception.R.J.V. BertinI. Israël2002-06-12Z2011-03-11T08:54:56Zhttp://cogprints.org/id/eprint/2272This item is in the repository with the URL: http://cogprints.org/id/eprint/22722002-06-12ZOutstanding questions about phonological processing in dyslexiaIt is widely accepted that developmental dyslexia results from some sort of phonological deficit. Yet, it can be argued that phonological representations and their processing have been insufficiently tested in dyslexia research.
Firstly, claims about how tasks tap into certain kinds of representations or processes are best appreciated in the light of an explicit information-processing model. Here, a cognitive model of lexical access is described, incorporating speech perception, reading and object recognition. The model emphasises that phonological forms of lexical items are distinct from non-lexical phonological representations
Secondly, phonology, as a linguistic discipline, teaches us that there is much more to it than phonemic categorisation and awareness. The phonological level of representation also embodies phonotactic regularities, patterns of phoneme assimilation and alternation, as well as supra-segmental knowledge pertaining to syllable structure, stress, intonation and rhythm. All these aspects are in part language-dependent, and therefore must be learnt by children in order to become proficient native speakers and listeners. If phonological representations were affected in dyslexia, dyslexic children would presumably have difficulties acquiring these aspects of their language. This prediction is as yet untested. A possible research agenda is outlined, aiming to provide a more comprehensive assessment of the phonological theory of dyslexia.
Franck Ramus2002-03-08Z2011-03-11T08:54:54Zhttp://cogprints.org/id/eprint/2122This item is in the repository with the URL: http://cogprints.org/id/eprint/21222002-03-08ZReconstructing passively travelled manoeuvres:
Visuo-vestibular interactions.We recently published a study of the reconstruction of passively travelled trajectories from optic flow. Perception was prone to illusions in a number of conditions, and not always veridical in the other conditions. Part of the illusionary reconstructed trajectories could be explained if we assume that the subjects based their reconstruction on the ego-motion percept obtained during the stimulus' initial moments. In the current paper, we test this hypothesis using a novel paradigm. If indeed the final reconstruction is governed by the initial percept, then additional, extra-retinal information that modifies the initial percept should predictably alter the final reconstruction. We supplied extra-retinal stimuli tuned to supplement the information that was underrepresented or ambiguous in the optic flow: the subjects were physically displaced or rotated at the onset of the visual stimulus. A highly asymmetric velocity profile (high acceleration, very low deceleration) was used. Subjects were required to guide an input device (in the form of a model vehicle; we measured position and orientation) along the perceived trajectory. We show for the first time that a vestibular stimulus of short duration can influence the perception of a much longer lasting visual stimulus. Perception of the ego-motion translation component in the visual stimulus was improved by a linear physical displacement; perception of the ego-motion rotation component by a physical rotation. This led to a more veridical reconstruction in some conditions, but it could also lead to less veridical reconstructions in other conditions.R.J.V. BertinA. Berthoz2001-06-20Z2011-03-11T08:54:43Zhttp://cogprints.org/id/eprint/1632This item is in the repository with the URL: http://cogprints.org/id/eprint/16322001-06-20ZRestriction of task processing time affects cortical activity during processing of a cognitive task: an event-related slow cortical potential studyAs is known from psychometrics, restriction of task processing time by the instruction to respond as quickly and accurately as possible leads to task-unspecific cognitive processing. Since this task processing mode is used in most functional neuroimaging studies of human
cognition, this may evoke cortical activity that is functionally not essential for the particular task under investigation. Using topographic recordings of event-related slow cortical potentials, two experiments have been performed to investigate whether cortical activity during
processing of a visuo-spatial imagery task is substantially influenced by the time provided to process the task. Furthermore, it was investigated whether this effect is additionally modulated by a subjects task-specific ability. The instruction to respond as quickly and accurately as possible led to increased negative slow cortical potential amplitudes over parietal and frontal regions and significantly interacted with task-specific ability. While cortical activity recorded over parietal and frontal regions was different between subjects with low and high spatial ability when processing time was unrestricted, no such differences were found between ability groups when subjects
were instructed to answer both quickly and accurately. These results suggest that restricting processing time has considerable effects on the amount and the pattern of brain activity during cognitive processing and should be taken into account more explicitly in the experimental design and interpretation of neuroimaging studies of cognition.Claus LammHerbert BauerOliver VitouchSusanne DurecRoswitha GronisterReinhard Gstättner2002-09-26Z2011-03-11T08:55:00Zhttp://cogprints.org/id/eprint/2475This item is in the repository with the URL: http://cogprints.org/id/eprint/24752002-09-26ZThe Split-Brain debate revisited: On the importance of language and self-recognition for right hemispheric consciousness. In this commentary I use recent empirical evidence and
theoretical analyses concerning the importance of language and the meaning of self-recognition to reevaluate the claim that the right mute hemisphere in commissurotomized patients possesses a full consciousness. Preliminary data indicate that inner speech is deeply linked to self-awareness; also, four hypotheses concerning the crucial role inner speech plays in self-focus are presented. The legitimacy of self-recognition as a strong operationalization of self-awareness in the right hemisphere is also questioned on the basis that it might rather tap a preexisting body awareness having little to do with an access to mental events. I conclude with the formulation of an alternative interpretation of commissurotomy according to self-awareness — a “complete” one in the left hemisphere and a “primitive” one in the right hemisphere,Alain Morin2001-04-08Z2011-03-11T08:54:37Zhttp://cogprints.org/id/eprint/1439This item is in the repository with the URL: http://cogprints.org/id/eprint/14392001-04-08ZTestosterone and grasp-reflex differences in human neonatesAccording to the Geschwind-Behan-Galaburda (GBG) hypothesis, prenatal testosterone (T) causes a slowing in the development of the left brain with a consequent compensatory growth in the right brain, creating a reverse organisation of the cerebral lateralisation. That is, left- and right-handedness might be associated with high and low prenatal T levels, respectively. To test this
hypothesis, the relations of T levels (umbilical cord blood) to grasp-reflex strengths were studied in human neonates. Handedness was assessed by measuring
the grasp-reflex strengths from the right and left hands in 10 trials from each hand alternatively. There were two handedness groups: right-handers (R-L significantly
greater than zero) and left-handers (significantly smaller than zero). Contrary to the GBG model, the mean free T concentration was found to be significantly higher in
right-handers than left-handers for males and females. There was no significant difference in the total T levels between right- and left-handers. Free T concentrations positively correlated with R-L grasp-reflex strengths, i.e. right-handedness increased as T increased, and left-handedness increased as T decreased. Contrary to these positive correlations, T negatively correlated with
the grasp-reflex strengths from the right and left hands. These results partly supported the GBG hypothesis for this spinal-motor-asymmetry model. Total T did not significantly correlate with grasp-reflex strengths. The results suggest that prenatal T may at least play a role in prenatal determination of spinal motor lateralisation, with a possible consequent upward regulation of cerebral
lateralisation.
Uner TanMeliha Tan2003-06-03Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1989This item is in the repository with the URL: http://cogprints.org/id/eprint/19892003-06-03ZConceptual coordination bridges information processing and neurophysiologyInformation processing theories of memory and skills can be reformulated in terms of how categories are physically and temporally related, a process called conceptual coordination. Dreaming can then be understood as a story understanding process in which two mechanisms found in everyday comprehension are missing: conceiving sequences (chunking categories in time as a higher-order categorization) and coordinating across modalities (e.g., relating the sound of a word and the image of its meaning). On this basis, we can readily identify isomorphisms between dream phenomenology and neurophysiology, and explain the function of dreaming as facilitating future coordination of sequential, cross-modal categorization (i.e., REM sleep lowers activation thresholds, unlearning).William Clancey2000-05-09Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/143This item is in the repository with the URL: http://cogprints.org/id/eprint/1432000-05-09ZError detection and the Error-related ERP in patients with lesions involving the anterior cingulate and adjacent regionsEvidence indicates that the anterior cingulate region generates what appears to be a specific electrophysiological marker for the monitoring of error responses. When an auditory or visual stimulus is presented in such a way that the subject is likely to make an error, averaged encephalography (EEG) trials to erroneous responses consistently show a negative-going waveform which has been coined the error-related negativity (ERN). We examined ERNs in patients with a ruptured aneurysm of the anterior communicating artery (AACA), who are particularly prone to showing damage in the anterior cingulate and adjacent regions, and frequently display a variety of behavioral and cognitive disturbances such as disorientation, confabulation, apathy, unawareness of deficit, and problems of attention, control and monitoring. We found that these patients generally did not produce an ERN in comparison to healthy control participants suggesting that the anterior cingulate is essential for the ERN response. However, the patients' error rates were comparable to that of the controls and they showed a dissociation between overt error awareness and ERN production, suggesting that the ERN does not simply represent an error detection signal.Brigitte StemmerSidney J. SegalowitzWolfgang WitzkeSieglinde LacherPaul Walter Schönle2000-06-14Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/149This item is in the repository with the URL: http://cogprints.org/id/eprint/1492000-06-14ZTHE MIND AND BRAIN SCHOLAR AS A HITCH-HIKER IN POST-GUTENBERG GALAXY: PUBLISHING AT 2000 AND BEYONDElectronic journal (e-journal) publishing has started to change the ways we think about publish-ing. However, many scholars and scientists in the mind and brain sciences are still ignorant of the new possibilities and on-going debates. This paper will provide a summary of the issues in-volved, give an update of the current discussion, and supply practical information on issues re-lated to e- journal publishing and self-archiving relevant for the mind and brain sciences. Issues such as differences between traditional and e-journal publishing, open archive initiatives, world-wide conventions, quality control, costs involved in e-journal publishing, and copyright questions will be addressed. Practical hints on how to self-archive, how to submit to the e-journal Psycolo-quy, how to create an open research archive, and where to find information relevant to e-publishing will be supplied.Brigitte StemmerMarianne CorreYves Joanette2000-05-13Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/147This item is in the repository with the URL: http://cogprints.org/id/eprint/1472000-05-13ZThe study of the regenesis of mind in the 21st centuryThe enigma of consciousness and the brain-mind relationship will - most likely - be unveiled in the 21st century through the new technologies developed at the end of the 20th century and new technologies yet to come. The new technologies will be used to tackle the problem from evolu-tionary, developmental, normal and pathological brain functioning. A major contribution, how-ever, will surface when investigating a particular perspective of pathological brain functioning - a perspective that has not received any attention in the past: the investigation of the re-emergence of mind out of prolonged coma and coma like states.Paul Walter SchönleBrigitte Stemmer2000-05-13Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/146This item is in the repository with the URL: http://cogprints.org/id/eprint/1462000-05-13ZNeuropragmatics in the 21st centuryOne of the great challenges of the new millennium is the continuing search of how the mind works. Although a relatively young field, the study of neuropragmatics can greatly contribute to this search by its interdisciplinary nature, the possibility to be applied to different research meth-ods and by the opportunity to study its nature by taking vastly different perspectives.Brigitte StemmerPaul Walter Schönle2000-07-04Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/150This item is in the repository with the URL: http://cogprints.org/id/eprint/1502000-07-04ZConstructional Tools as the Origin of Cognitive CapacitiesIt is argued that cognitive capacities can be understood as the outcome of the collective action of a set of agents created by tools that explore possible behaviours and train the agents to behave in such appropriate ways as may be discovered. The coherence of the whole system is assured by a combination of vetting the performance of new agents and dealing appropriately with any faults that the whole system may develop. This picture is shown to account for a range of cognitive capacities, including language.Brian D. Josephson2001-07-23Z2011-03-11T08:54:45Zhttp://cogprints.org/id/eprint/1713This item is in the repository with the URL: http://cogprints.org/id/eprint/17132001-07-23ZDifferent organization of concepts and meaning systems in the two cerebral hemispheresThe left and right hemispheres are asymmetrical with respect to specific cognitive abilities as well as organization of concepts and meaning systems. Several hemi-field experiments using the notion of typicality in different cognitive domains are described in this paper, as well as experiments which tap the notion of hemispheric-specific schemata. The results suggest that the 2 cerebral hemispheres can process the same external information but in ways which suggest asymmetry in concept and meaning organization.Dahlia Zaidel2005-05-02Z2011-03-11T08:54:46Zhttp://cogprints.org/id/eprint/1725This item is in the repository with the URL: http://cogprints.org/id/eprint/17252005-05-02ZDifferent organization of concepts and meaning systems in the two cerebral hemispheresThe left and right hemispheres are asymmetrical with respect to specific cognitive abilities as well as organization of concepts and meaning systems. Several hemi-field experiments using the notion of typicality in different cognitive domains are described in this paper, as well as experiments which tap the notion of hemispheric-specific schemata. The results suggest that the 2 cerebral hemispheres can process the same external information but in ways which suggest asymmetry in concept and meaning organization.Dahlia Zaidel2000-10-29Z2011-03-11T08:54:25Zhttp://cogprints.org/id/eprint/1060This item is in the repository with the URL: http://cogprints.org/id/eprint/10602000-10-29ZDo patients with damage to the anterior cingulate and adjacent regions produce an error-related negativity (ERN)?Averaged EEG trials to erroneous responses consistently show a negative-going waveform which has been coined the error-related negativity (ERN) (for a summary see Falkenstein et al., 2000). Evidence points to the neural generator of the ERN to be distributed somewhere along the medial prefrontal cortex, most likely within the anterior cingulate. This suggests that patients with lesions in the anterior cingulate region should not produce an ERN. In order to test this hypothesis, we investigated five patients with a ruptured aneurysm of the anterior communicating artery (AACA) leading to damage of neural substrates in the anterior cingulate region. Four of the five patients did not produce an ERN in one paradigm, or they produced a highly deviant waveform. These results contrast with findings showing that patients with damage involving the lateral prefrontal cortex do produce an ERN (Gehring & Knight, 2000). This dissociation suggests that the anterior cingulate region is essential to initiate the ERN response. One patient showed an ERN in both paradigms possibly due to damage that differed from that of the other patients, or individual variation.
It has further been suggested that elicitation of the ERN is dependent on overt error awareness. Two of our patients showed relatively good cognitive functioning compared to the other patients, and during EEG recording they noticed when they had made an error as indicated by swearing, comments or gestures. Nevertheless, one of the two patient clearly did not show an ERN in both paradigms, and the other patient did show an ERN in one but not in the other paradigm. It thus seems that awareness of errors as signaled by overt error detection may be mediated by circuits outside of those necessary for ERN production. Brigitte StemmerSidney J. SegalowitzWolfgang WitzkeSieglinde LacherPaul Walter Schoenle2002-06-29Z2011-03-11T08:54:56Zhttp://cogprints.org/id/eprint/2302This item is in the repository with the URL: http://cogprints.org/id/eprint/23022002-06-29ZA Functional Architecture Approach to Neural SystemsThe technology for the design of systems to perform extremely complex combinations of real-time functionality has developed over a long period. This technology is based on the use of a hardware architecture with a physical separation into memory and processing, and a software architecture which divides functionality into a disciplined hierarchy of software components which exchange unambiguous information. This technology experiences difficulty in design of systems to perform parallel processing, and extreme difficulty in design of systems which can heuristically change their own functionality. These limitations derive from the approach to information exchange between functional components. A design approach in which functional components can exchange ambiguous information leads to systems with the recommendation architecture which are less subject to these limitations. Biological brains have been constrained by natural pressures to adopt functional architectures with this different information exchange approach. Neural networks have not made a complete shift to use of ambiguous information, and do not address adequate management of context for ambiguous information exchange between modules. As a result such networks cannot be scaled to complex functionality. Simulations of systems with the recommendation architecture demonstrate the capability to heuristically organize to perform complex functionality.
l andrew coward2010-04-01T11:36:55Z2011-03-11T08:57:35Zhttp://cogprints.org/id/eprint/6812This item is in the repository with the URL: http://cogprints.org/id/eprint/68122010-04-01T11:36:55ZNeuropragmatics: Brain and communicationThere is no abstract for this paper.Bruno G. BaraMaurizio Tirassamaurizio.tirassa@unito.it2001-10-27Z2011-03-11T08:54:48Zhttp://cogprints.org/id/eprint/1843This item is in the repository with the URL: http://cogprints.org/id/eprint/18432001-10-27ZNeuropsychological and conditioned blocking performance in patients with schizophrenia: assessment of the contribution of neuroleptic dose, serum levels and dopamine D2-receptor occupancyIntroduction:
Patients with schizophrenia are widely reported to show impairments of attention and neuropsychological performance, but the extent to which this is attributable to medication and dopamine (DA) function remains largely unexplored.
Methods:
We describe here the putative influence of 1) the dose of antipsychotic medication (chlorpromazine equivalents, CPZ), 2) the antipsychotic serum concentration (neuroleptic units in terms of butyrophenone displacement from animal neostriatum) and 3) the approximated DA D2-receptor occupancy in the brain (based on regression curves from 11 studies published for 5 neuroleptics) - - on conditioned blocking (CB) measures of attention and performance on a neuropsycholog-ical battery. We studied 108 patients with schizophrenia with 62 healthy controls.
Results:
1) Antipsychotic serum concentration and D2-occupancy were higher in patients with a paranoid vs. non-paranoid diagnosis, and in female vs. male patients (independent of symptom severity).
2) Controlling for D2-occupancy removed the difference between high CB in paranoid and impaired low CB measures of selective attention in nonparanoid patients.
3) Similar partial correlations for antipsychotic drug dose and serum levels of DA D2-blocking activity with performance on the trail-making and picture completion tests (negative) and the block-design test (positive) showed the functional importance of DA-related activity.
4) High estimates of D2-occupancy were related to impaired verbal fluency - but - were associated with improved recall of stories, especially in paranoid patients.
5) Non-dopaminergic aspects of medication (i.e. CPZ-dependent but not D2-occupancy-associated) impaired verbal recall in males (left-hemisphere function) and non-verbal performance in females (reflecting right hemisphere function).
Conclusions:
This first study of its kind tentatively imputes a role for DA D2-related activity in left frontal (e.g. CB and verbal fluency) and temporal lobe functions (verbal recall), as well as in some non-verbal abilities mediated more in the right hemisphere of patients with schizophrenia
R.D. OadesM.L. RaoS. BenderG. SartoryB.W. Müller2003-12-18Z2011-03-11T08:55:25Zhttp://cogprints.org/id/eprint/3320This item is in the repository with the URL: http://cogprints.org/id/eprint/33202003-12-18ZTherapeutic applications of computer models of brain activity for Alzheimer disease. THERAPEUTIC IMPLICATIONS OF COMPUTER MODELS OF BRAIN ACTIVITY FOR ALZHEIMER DISEASE.Prof Wlodzislaw Duch2000-02-01Z2011-03-11T08:53:41Zhttp://cogprints.org/id/eprint/134This item is in the repository with the URL: http://cogprints.org/id/eprint/1342000-02-01ZEFFECTS OF ASPIRATION VERSUS NEUROTOXIC LESIONS OF THE AMYGDALA ON EMOTIONAL RESPONSES IN MONKEYSAll previous reports describing alterations in emotional reactivity after amygdala damage in monkeys were based on aspiration or radiofrequency lesions which likely disrupted fibers of passage coursing to and from adjacent ventral and medial temporal cortical areas. To determine whether this associated indirect damage was responsible for some or all of the changes described earlier, we compared the changes induced by aspiration of the amygdala to those induced by fiber-sparing neurotoxic lesions. Four different stimuli, two with and two without a social component, were used to evaluate the expression of Defense, Aggression, Submission, and Approach responses. In unoperated controls, Defense and Approach behaviors were elicited by all four stimuli, "social" and inanimate alike, whereas Aggression and Submission responses occurred only in the presence of the two "social" stimuli. Furthermore, all Defense reactions were reduced with an attractive inanimate item, while Freezing was selectively increased with an aversive one. Relative to controls, monkeys with neurotoxic amygdala lesions showed the same array of behavioral changes as those with aspiration lesions, namely reduced fear and aggression, increased submission, and excessive manual and oral exploration. Even partial neurotoxic lesions involving less than two-thirds of the amygdala significantly altered fear and manual exploration. These findings convincingly demonstrate that the amygdala is crucial for the normal regulation of emotions in monkeys. Nevertheless, since some of the symptoms observed after neurotoxic lesions were less marked than those seen after aspiration lesions, the emotional disorders described earlier after amygdalectomy in monkeys were likely exacerbated by the attendant fiber damage.Martine MeunierJocelyne BachevalierElisabeth A. MurrayLudie MálkováMortimer Mishkin2000-02-02Z2011-03-11T08:53:41Zhttp://cogprints.org/id/eprint/135This item is in the repository with the URL: http://cogprints.org/id/eprint/1352000-02-02ZIncidences of asymmetries for the palmar grasp reflex in neonates and hand preference in adultsIt was hypothesized that adult handedness might be predicted from the neonatal grasp reflex. Grasp reflex was measured from right and left hand (10 trials for each hand) in neonates. According to significance for the difference between the mean grasp reflex strength from the right and left hands, the subjects were designated as right-, left-, and mixed-handers. Adult hand preference was assessed by Edinburgh Handedness Inventory. The percentage of left-handedness (8.3%) in neonates coincided with adult left-handedness (6.3-9.2%). The percentage of consistent right-hand preference in adults coincided with percentage of right-handedness in neonates (25.7%). The high percentage of neonatal mixed-handedness was similar to that to be expected from the right shift model of hand preference. It was concluded that left-handedness and consistent right- handedness may be determined prenatally, under genetic and/or hormonal control, and that a large majority of neonatal handedness, mixed-handers, might change their hand preference in favor of right-handedness under socio-cultural and developmental influences of speech centres.Uner TanMeliha Tan2000-05-13Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/145This item is in the repository with the URL: http://cogprints.org/id/eprint/1452000-05-13ZDiscourse studies in neurologically impaired populations: A quest for actionOrganism and environment are in a state of constant interaction, and discourse is vie-wed as one form of manifestation of this interaction. Through the study of discourse in-sights can be gained into those components that bring about mental events. Verbal structure, communication of beliefs and action/interaction are highly interactive dimensi-ons of discourse. Taking this perspective as a framework, the findings of discourse stu-dies with particular emphasis on right-hemisphere brain damaged individuals are discussed. Neurolinguistic studies of discourse can be divided into four categories: (1) studies that focus primarily at providing a detailed description of the structural and inter-actional abilities of brain-damaged individuals, (2) studies that are mainly concerned with investigating the processing aspects of discourse, (3) studies that investigate the influ-ence of cognitive systems such as attention or memory on discourse processing, and (4) studies that try to relate discourse processing mechanisms to underlying biological sub-strates or neurophysiological mechanisms. A quest is made for future research to base discourse studies on well-defined processing theories, to include different processing components and levels, and to systematically investigate the impact of facets of cogniti-ve systems on such processing. Established methodological approaches should be complemented by electrophysiological procedures (such as the event related potentials technique), or functional imaging techniques (such as fMRI) to tackle relationships bet-ween discourse processing mechanisms, cognitive systems and underlying biological mechanisms. Consideration of the influence of biochemical processes (such as asym-metries of neurotransmitters, endocrine functions or influence of pharmacological agents) on component processes may add to our insights.Brigitte Stemmer2010-04-01T11:37:03Z2011-03-11T08:57:35Zhttp://cogprints.org/id/eprint/6811This item is in the repository with the URL: http://cogprints.org/id/eprint/68112010-04-01T11:37:03ZCommunicative competence and the architecture of the mind/brainCognitive pragmatics is concerned with the mental processes involved in intentional communication. I discuss a few issues that may help clarify the relationship between this area and the broader cognitive science and the contribution that they give, or might give, to each other. Rather than dwelling on the many technicalities of the various theories of communication that have been advanced, I focus on the different conceptions of the nature and the architecture of the mind/brain that underlie them. My aims are, first, to introduce and defend mentalist views of communication in general; second, to defend one such view, namely that communication is a cognitive competence, that is, a faculty, and the underlying idea that the architecture of the mind/brain is domain-specific; and, third, to review the (scarce) neuropsychological evidence that bears on these issues.Maurizio Tirassamaurizio.tirassa@unito.it1999-07-16Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/183This item is in the repository with the URL: http://cogprints.org/id/eprint/1831999-07-16ZThe Fifth InfluenceThis article is a theoretical consideration on the role of sensory pleasure and mental joy as optimizers of behavior. It ends with an axiomatic proposal. When they compare the human body to its environment, Philosophers recognise the cosmos as the Large Infinite, and the atomic particles as the Small Infinite. The human brain reaches such a degree of complexity that it may be considered as a third infinite in the universe, a Complex Infinite. It follows that any force capable of moving such an infinite deserves a place among the forces of the universe. Physicists have recognized four forces, the gravitational, the electromagnetic, the weak, and the strong nuclear force. Forces are defined in four dimentions (reversible or not in time) and it is postulated that these forces are valid and applicable everywhere. Pleasure and displeasure, the affective axis of consciousness, can move the infinitely complex into action and no human brain can avoid the trend to maximize its pleasure. Therefore, we suggest, axiomatically, that the affective capability of consciousness operates in a way similar to the four forces of the Physics, i.e. influences the behavior of conscious agents in a way similar to the way the four forces influence masses and particles. However, since a mental phenomenon is dimensioneless we propose to call the affective capability of consciousness the fifth influence rather than the fifth force.Michel CabanacRemi A. CabanacHarold T. Hammel1999-07-14Z2011-03-11T08:53:40Zhttp://cogprints.org/id/eprint/106This item is in the repository with the URL: http://cogprints.org/id/eprint/1061999-07-14ZThe Future of Research on Electroreception and Electrocommunication.Besides the rounding out of presently active areas, six are selected for predictions of marked advance. (1) Most discoveries will be in cellular componentry and molecular mechanisms for one or another class of receptors or central pathways. (2) More major taxa will be found with electroreceptive species, possibly birds, reptiles or invertebrates, representing independent evolutionary "inventions". (3) Electric organs with weak and episodic electric discharges will be found in new taxa; first, among siluriforms. (4) New examples are expected, like lampreys, where synchronized muscle action potentials add up to voltages in the range of weakly electric fish. Some of these will look like intermediates in the evolution of electric organs. (5) Ethological significance will be found for a variety of known physiological features. Exs.: uranoscopids, skates and weakly electric catfish with episodic electric discharges of unknown role; electroreceptive ability of some of the diverse group having Lorenzinian-type ampullae (besides elasmobranchs) including lampreys, chimaeras, lungfish, sturgeons, paddlefish, and salamanders; gymnotiform and mormyrid detection of capacitive component of impedance. (6) The organization of some higher functions in the cerebellum and forebrain will gradually come to light.Theodore H. Bullock1999-12-15Z2011-03-11T08:53:41Zhttp://cogprints.org/id/eprint/125This item is in the repository with the URL: http://cogprints.org/id/eprint/1251999-12-15ZIntroductionThe introduction to the special issue briefly discusses the origins and development of the word "pragmatics", pragmatic theory and its application to neurolinguistics. The special issue covers a total of 11 articles investigating pragmatic and neuropragmatic issues from different theoretical, experimental and clinical perspectives.Brigitte Stemmer2001-03-13Z2011-03-11T08:54:36Zhttp://cogprints.org/id/eprint/1369This item is in the repository with the URL: http://cogprints.org/id/eprint/13692001-03-13ZMagnetic Resonance Imaging Brain Size/IQ Relations in Turkish University StudentsThe relation of IQ (Cattell's Culture Fair Intelligence Test) to brain size was studied in 103 right- and left-handed men and women at Ataturk University in eastern Turkey. Cerebral areas were measured on a midsagittal
section of the brain using MRI. An overall correlation of 40 was found between MRI-measured total area and IQ thereby further supporting the IQ¯brain size hypothesis. Additional analyses suggested that these results may need qualification. In men, only anterior cerebral area correlated with IQ. In women, total and posterior cerebral areas were correlated with IQ. Other results varied by handedness.Uner TanMeliha TanPinar PolatYasar CeylanSelami SumaAdnan Okur1998-12-21Z2011-03-11T08:54:17Zhttp://cogprints.org/id/eprint/778This item is in the repository with the URL: http://cogprints.org/id/eprint/7781998-12-21ZModelling the Developing Mind: From Structure to ChangeThis paper presents a theory of cognitive change. The theory assumes that the fundamental causes of cognitive change reside in the architecture of mind. Thus, the architecture of mind as specified by the theory is described first. It is assumed that the mind is a three-level universe involving (1) a processing system that constrains processing potentials, (2) a set of specialized capacity systems that guide understanding of different reality and knowledge domains, and (3) a hypecognitive system that monitors and controls the functioning of all other systems. The paper then specifies the types of change that may occur in cognitive development (changes within the levels of mind, changes in the relations between structures across levels, changes in the efficiency of a structure) and a series of general (e.g., metarepresentation) and more specific mechanisms (e.g., bridging, interweaving, and fusion) that bring the changes about. It is argued that different types of change require different mechanisms. Finally, a general model of the nature of cognitive development is offered. The relations between the theory proposed in the paper and other theories and research in cognitive development and cognitive neuroscience is discussed throughout the paper.Andreas DemetriouAthanassios Raftopoulos1999-07-06Z2011-03-11T08:53:40Zhttp://cogprints.org/id/eprint/104This item is in the repository with the URL: http://cogprints.org/id/eprint/1041999-07-06ZNeural activation, information, and phenomenal consciousness.O'Brien & Opie defend a "vehicle" rather than a "process" theory of consciousness largely on the grounds that only conscious information is "explicit". I argue that preconscious and unconscious representations can be functionally explicit (semantically well-formed and causally active). I also suggest that their analysis of how neural activation space mirrors the information structure of phenomenal experience fits more naturally into a dual-aspect theory of information than into their reductive physicalism.Max Velmans1999-12-15Z2011-03-11T08:53:41Zhttp://cogprints.org/id/eprint/126This item is in the repository with the URL: http://cogprints.org/id/eprint/1261999-12-15ZAn On-Line Interview with Noam Chomsky: On the Nature of Pragmatics and Related IssuesThe authors and editor of the special issue of Brain and Language: Pragmatics: Theoretical and Clinical Issues as well as the editor of Brain and Language framed some questions which were sent to and readily discussed by Noam Chomsky via e-mail.Brigitte Stemmer2002-06-29Z2011-03-11T08:54:56Zhttp://cogprints.org/id/eprint/2303This item is in the repository with the URL: http://cogprints.org/id/eprint/23032002-06-29ZA Physiologically Based System Theory of ConsciousnessA system which uses large numbers of devices to perform a complex functionality is forced to adopt a simple functional architecture by the needs to construct copies of, repair, and modify the system. A simple functional architecture means that functionality is partitioned into relatively equal sized components on many levels of detail down to device level, a mapping exists between the different levels, and exchange of information between components is minimized. In the instruction architecture functionality is partitioned on every level into instructions, which exchange unambiguous system information and therefore output system commands. The von Neumann architecture is a special case of the instruction architecture in which instructions are coded as unambiguous system information. In the recommendation (or pattern extraction) architecture functionality is partitioned on every level into repetition elements, which can freely exchange ambiguous information and therefore output only system action recommendations which must compete for control of system behavior. Partitioning is optimized to the best tradeoff between even partitioning and minimum cost of distributing data. Natural pressures deriving from the need to construct copies under DNA control, recover from errors, failures and damage, and add new functionality derived from random mutations has resulted in biological brains being constrained to adopt the recommendation architecture. The resultant hierarchy of functional separations can be the basis for understanding psychological phenomena in terms of physiology. A theory of consciousness is described based on the recommendation architecture model for biological brains. Consciousness is defined at a high level in terms of sensory independent image sequences including self images with the role of extending the search of records of individual experience for behavioral guidance in complex social situations. Functional components of this definition of consciousness are developed, and it is demonstrated that these components can be translated through subcomponents to descriptions in terms of known and postulated physiological mechanisms. l andrew coward1999-07-14Z2011-03-11T08:53:52Zhttp://cogprints.org/id/eprint/388This item is in the repository with the URL: http://cogprints.org/id/eprint/3881999-07-14ZSubjekt und Selbstmodell. Die Perspektivität phänomenalen Bewußtseins vor dem Hintergrund einer naturalistischen Theorie mentaler RepräsentationThis book contains a representationalist theory of self-consciousness and of the phenomenal first-person perspective. It draws on empirical data from the cognitive and neurosciences.Thomas K. Metzinger2000-03-03Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/142This item is in the repository with the URL: http://cogprints.org/id/eprint/1422000-03-03ZObservations on the relationship between verbal explicit and implicit memory and neuronal density in the left and right hippocampus in temporal lobectomy patients.The relationship between neuronal density and verbal memory in left and right hippocampal subfields was investigated in patients who underwent surgery for alleviation of temporal lobe epilepsy. The surgery consisted of unilateral partial removal of the hippocampus along with the anterior temporal lobe and amygdala. Study 1 looked at post-surgical explicit versus implicit verbal memory for lists of words while Study 2 looked at pre- and post-surgical explicit memory for word pairs. Left subfield CA1 appeared to be the most consistently involved in explicit and implicit memory. The results of the two studies confirm presence of hemispheric asymmetry in verbal memory. The notion that hippocampal control of memory is most apparent in post-surgical performance is discussed.Dahlia W. ZaidelMargaret EsiriElizabeth Beardsworth1998-06-22Z2011-03-11T08:54:12Zhttp://cogprints.org/id/eprint/695This item is in the repository with the URL: http://cogprints.org/id/eprint/6951998-06-22ZThe evolution of what?There is now a huge amount of interest in consciousness among scientists as well as philosophers, yet there is so much confusion and ambiguity in the claims and counter-claims that it is hard to tell whether any progress is being made. This ``position paper'' suggests that we can make progress by temporarily putting to one side questions about what consciousness is or which animals or machines have it or how it evolved. Instead we should focus on questions about the sorts of architectures that are possible for behaving systems and ask what sorts of capabilities, states and processes, might be supported by different sorts of architectures. We can then ask which organisms and machines have which sorts of architectures. This combines the standpoint of philosopher, biologist and engineer. If we can find a general theory of the variety of possible architectures (a characterisation of ``design space'') and the variety of environments, tasks and roles to which such architectures are well suited (a characterisation of ``niche space'') we may be able to use such a theory as a basis for formulating new more precisely defined concepts with which to articulate less ambiguous questions about the space of possible minds. For instance our initially ill-defined concept (``consciousness'') might split into a collection of more precisely defined concepts which can be used to ask unambiguous questions with definite answers. As a first step this paper explores a collection of conjectures regarding architectures and their evolution. In particular we explore architectures involving a combination of coexisting architectural levels including: (a) reactive mechanisms which evolved very early, (b) deliberative mechanisms which evolved later in response to pressures on information processing resources and (c) meta-management mechanisms that can explicitly inspect evaluate and modify some of the contents of various internal information structures. It is conjectured that in response to the needs of these layers, perceptual and action subsystems also developed layers, and also that an ``alarm'' system which initially existed only within the reactive layer may have become increasingly sophisticated and extensive as its inputs and outputs were linked to the newer layers. Processes involving the meta-management layer in the architecture could explain the origin of the notion of ``qualia''. Processes involving the ``alarm'' mechanism and mechanisms concerned with resource limits in the second and third layers gives us an explanation of three main forms of emotion, helping to account for some of the ambiguities which have bedevilled the study of emotion. Further theoretical and practical benefits may come from further work based on this design-based approach to consciousness. A deeper longer term implication is the possibility of a new science investigating laws governing possible trajectories in design space and niche space, as these form parts of high order feedback loops in the biosphere.Aaron Sloman1998-10-20Z2011-03-11T08:53:51Zhttp://cogprints.org/id/eprint/365This item is in the repository with the URL: http://cogprints.org/id/eprint/3651998-10-20ZTHE THEORY OF THE ORGANISM-ENVIRONMENT SYSTEM: II. SIGNIFICANCE OF NERVOUS ACTIVITY IN THE ORGANISM-ENVIRONMENT SYSTEMThe relation between mental processes and brain activity is studied from the point of view of the theory of the organism-environment system. It is argued that the systemic point of view leads to a new kind of definition of the primary tasks of neurophysiology and to a new understanding of the traditional neurophysiological concepts. Neurophysiology is restored to its place as a part of biology: its task is the study of neurons as living units, not as computer chips. Neurons are living units which are organised as metabolic systems in connection with other neurons; they are not units which would carry out some psychological functions or maintain states which are typical only of the whole organism-environment system. Psychological processes, on the other hand, are processes always comprising the whole organism-environment system.Timo Jarvilehto1998-08-20Z2011-03-11T08:53:38Zhttp://cogprints.org/id/eprint/60This item is in the repository with the URL: http://cogprints.org/id/eprint/601998-08-20ZAre there psychotic Neanderthals amongst us?No abstractWim E. Crusio2003-10-17Z2011-03-11T08:55:22Zhttp://cogprints.org/id/eprint/3218This item is in the repository with the URL: http://cogprints.org/id/eprint/32182003-10-17ZCompeting for Consciousness: A Darwinian Mechanism at an Appropriate Level of ExplanationTreating consciousness as awareness or attention greatly underestimates it, ignoring the temporary levels of organization associated with higher intellectual function (syntax, planning, logic, music). The tasks that require consciousness tend to be the ones that demand a lot of resources. Routine tasks can be handled on the back burner but dealing with ambiguity, groping around offline, generating creative choices, and performing precision movements may temporarily require substantial allocations of neocortex. Here I will attempt to clarify the appropriate levels of explanation (ranging from quantum aspects to association cortex dynamics) and then propose a specific mechanism (consciousness as the current winner of Darwinian copying competitions in cerebral cortex) that seems capable of encompassing the higher intellectual function aspects of consciousness as well as some of the attentional aspects. It includes features such as a coding space appropriate for analogies and a supervisory Darwinian process that can bias the operation of other Darwinian processes.
William H Calvin2001-03-30Z2011-03-11T08:54:36Zhttp://cogprints.org/id/eprint/1420This item is in the repository with the URL: http://cogprints.org/id/eprint/14202001-03-30ZFrontal, temporal and lateralized brain function in children with attention-defiocit hyperactivity disorder: a psychophysiological and neuropsychological viewpoint on developmentIntroduction: This review considers deficits in the selective aspects of perception (i.e. attention) underlying symptoms of impaired attention and impulsivity in children with attention-deficit hyperactivity syndrome (ADHD) in terms of frontal and temporal lobe function and cerebral asymmetry.
Review: Tomographic studies suggest a disturbance of fronto-striatal function, but have neglected limbic contributions under activating conditions and are contradictory or equivocal on the nature of apparent lateralised differences of structure.
Functional neuropsychological (e.g. go/no-go and covert orienting of attention tasks) and psychophysiological studies (e.g. event-related potentials and mismatch negativity [1]) suggest that early and late stages of information processing are affected in both the frontal and temporal lobes.
Performance differences in young ADHD patients imply an impairment in the inter-cortical dialogue. Given the evidence for a normal specialisation in global processing in the right and the processing of details in the left hemisphere, the lateralised impairment may progress from situational ADHD (resulting in impaired selective aspects of perception on the right) to pervasive ADHD (inducing an additional impairment in decision making on the left: compare risk taking).
Conclusions: Accordingly a proportion of ADHD children may experience an early negative neurodevelopmental influence that only appears as the brain region matures (especially around 8-12 years of age) while others show an independent, longer term, delayed development of CNS function.
R.D. Oades2000-08-10Z2011-03-11T08:54:22Zhttp://cogprints.org/id/eprint/913This item is in the repository with the URL: http://cogprints.org/id/eprint/9132000-08-10ZPlatonic model of mind as an approximation to neurodynamicsHierarchy of approximations involved in simplification of microscopic theories, from sub-cellural to the whole brain level, is presented. A new approximation to neural dynamics is described, leading to a Platonic-like model of mind based on psychological spaces. Objects and events in these spaces correspond to quasi-stable states of brain dynamics and may be interpreted from psychological point of view. Platonic model bridges the gap between neurosciences and psychological sciences. Static and dynamic versions of this model are outlined and Feature Space Mapping, a neurofuzzy realization of the static version of Platonic model, described. Categorization experiments with human subjects are analyzed from the neurodynamical and Platonic model points of view. Wlodzislaw Duch2000-07-11Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/153This item is in the repository with the URL: http://cogprints.org/id/eprint/1532000-07-11ZRelative hand skill predicts academic ability: global deficits at the point of hemispheric indecisionPopulation variation in handedness (a correlate of cerebral dominance for language) is in part genetic and, it has been suggested, its persistence represents a balanced polymorphism with respect to cognitive ability. This hypothesis was tested in a sample of 12,770 individuals in a UK national cohort (the National Child Development Study) by assessing relative hand skill (in a square checking task) as a predictor of verbal, non-verbal, and mathematical ability and reading comprehension at the age of 11 years. Whereas some modest decrements were present in extreme right handers the most substantial deficits in ability were seen close to the point of equal hand skill (hemispheric indecision). For verbal ability females performed better than males, but the relationship to relative hand skill was closely similar for the two sexes; for reading comprehension males close to the point of equal hand skill showed greater impairments than females. Analysed by writing hand the relationship of ability to hand skill appeared symmetrical about the point of hemispheric indecision. The variation associated with degrees of dominance may reflect the operation of continuing selection on the gene (postulated to be X-Y linked) by which language evolved and speciation occurred.T. J. CrowL. R. CrowD. J. DoneS. Leask1998-06-22Z2011-03-11T08:54:12Zhttp://cogprints.org/id/eprint/694This item is in the repository with the URL: http://cogprints.org/id/eprint/6941998-06-22ZThe ``Semantics'' of Evolution: Trajectories and Trade-offs in Design Space and Niche SpaceThis paper attempts to characterise a unifying overview of the practice of software engineers, AI designers, developers of evolutionary forms of computation, designers of adaptive systems, etc. The topic overlaps with theoretical biology, developmental psychology and perhaps some aspects of social theory. Just as much of theoretical computer science follows the lead of engineering intuitions and tries to formalise them, there are also some important emerging high level cross disciplinary ideas about natural information processing architectures and evolutionary mechanisms and that can perhaps be unified and formalised in the future. There is some speculation about the evolution of human cognitive architectures and consciousness.Aaron Sloman1998-03-31Z2011-03-11T08:54:07Zhttp://cogprints.org/id/eprint/623This item is in the repository with the URL: http://cogprints.org/id/eprint/6231998-03-31ZVerbal Working Memory and Sentence ComprehensionThis target article discusses the verbal working memory system used in sentence comprehension. We review the idea of working memory as a short duration system in which small amounts of information are simultaneously stored and manipulated in the service of a task and that syntactic processing in sentence comprehension requires such a storage and computational system. We inquire whether the working memory system used in syntactic processing is the same as that used in verbally mediated tasks involving conscious, controlled processing. Various forms of evidence are considered: the relationship between individual differences in working memory and individual differences in the efficiency of syntactic processing; the effect of concurrent verbal memory load on syntactic processing; and syntactic processing in patients with poor short term memory, poor working memory, or aphasia. The experimental results suggest that the verbal working memory system specialized for assigning the syntactic structure of a sentence and for using that structure in determining sentence meaning is distinct from the working memory system that underlies the use of sentence meaning to accomplish further functions. We present a theory of the components of the verbal working memory system and suggestions as to its neural basis.David CaplanGloria Waters1998-07-27Z2011-03-11T08:54:15Zhttp://cogprints.org/id/eprint/731This item is in the repository with the URL: http://cogprints.org/id/eprint/7311998-07-27ZThe Engine of Awareness: Autonomous Synchronous RepresentationsObjections to functional explanations of awareness assert that although functional systems may be adequate to explain behavior, including verbal behavior consisting of assertions of awareness by an individual, they cannot provide for the existence of phenomenal awareness. In this paper, a theory of awareness is proposed that counters this assertion by incorporating two advances: (1) a formal definition of representation, expressed in a functional notation: Newell's Representation Law, and 2) the introduction of real time into the analysis of awareness. This leads to the definition of phenomenal awareness as existing whenever an object contains an autonomously updated configuration satisfying the Representation Law with respect to some aspects of its environment. The relational aspect of the Representation Law permits the development of multiple levels of awareness, which provides for the existence of illusions and hallucinations, and permits the identification of a new measure, accuracy of awareness . The relational perspective also permits the incorporation of referential concepts into the framework. Qualia can then be identified with referentially opaque elements of awareness. The functional form of the Representation Law is linked to neurophysiology and the underlying phenomena of chemistry and physics by phenomena involving activity-dependent connectivity.George McKee1998-08-04Z2011-03-11T08:53:38Zhttp://cogprints.org/id/eprint/55This item is in the repository with the URL: http://cogprints.org/id/eprint/551998-08-04ZDevelopmental changes in the event-related EEG theta response and P300Event-related potentials (ERPs) from 50 children (6 to 11 years) and ten adults were elicited by auditory passive, and by rare target and frequent nontarget stimuli, and analyzed in the time and frequency domains. The latency of the maximal theta response (or the theta frequency component of the ERP) was evaluated with respect to age and scalp topography effects. The major findings were: (1) The latency of the maximal theta response decreased with increasing age in children, although for each stimulus type and location adults had shorter latencies than the children. (2) The developmental time course of latency reduction depended on the electrode location, with the most prominent reduction occurring at 8 years at Cz, and no differences between children groups obtained for the frontal site. (3) Maximal theta response latency was strongly associated with the latency of the late parietal P400-700 (P3b) component in children. The results suggest that the developmental latency decrease in P300 processes originate from a decrease in the preceding theta-related processes and may reflect a speeding of cognitive stimulus evaluation.Juliana YordanovaVasil Kolev1998-06-11Z2011-03-11T08:53:48Zhttp://cogprints.org/id/eprint/310This item is in the repository with the URL: http://cogprints.org/id/eprint/3101998-06-11ZReview of Chalmers' The Conscious MindThe strength of Chalmers book is in philosophically relating different kinds of theoretical approaches to consciousness and especially explaining why a reductionist explanation is unsatisfactory. But by not working with the phenomenon itself and trying to relate its various forms to both biological and social facts, Chalmers has iroinically missed the opportunity to elevate his study above the reductionist approach. What is needed now is another book titled, The Conscious Animal: In search of a fundamental theory.William J. Clancey2000-07-10Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/151This item is in the repository with the URL: http://cogprints.org/id/eprint/1512000-07-10ZBrain asymmetry and facial attractiveness: Facial beauty is not simply in the eye of the beholder.We recently reported finding asymmetry in the appearance of beauty on the face [39]. Here we investigated whether facial beauty is a stable characteristic (on the owner's very face) or is in the perceptual space of the observer. We call the question 'the owner versus observer hypothesis'. We compared identity judgements and attractiveness ratings of observers. Subjects viewed left-left and right-right composites of faces and decided which most resembled the normal face (Experiment 1). Identity judgements (resemblance) are known to be associated with perceptual factors in the observer. Another group viewed the same normal faces and rated them on attractiveness (Experiment 2). In each experiment there were two separate viewing conditions, original and reversed (mirror-image). Lateral reversal did affect the results of Experiment 1 (confirming previous findings [3,18]) but did not affect the results of Experiment 2. The fact that lateral reversal did not affect the results of Experiment 2 suggests that facial attractiveness is more dependent on physiognomy (of the owner) and less dependent on an asymmetrical perceptual process (in the observer) than is facial identity. The results are discussed in the context of beautys biological significance and facial processing in the brain.Audrey C. ChenCraig GermanDahlia W. Zaidel2010-07-29T01:47:16Z2011-03-11T08:57:38Zhttp://cogprints.org/id/eprint/6891This item is in the repository with the URL: http://cogprints.org/id/eprint/68912010-07-29T01:47:16ZAge and interhemispheric transfer time: A failure to replicate.In a recent study with the Poffenberger paradigm, Brizzolara et al. reported longer estimates of interhemispheric transfer time (IHTT) for children aged 7 years than for adults. They interpreted this finding as evidence for incomplete functional maturity of the corpus callosum in young children. The present study was we were unable to replicate the age effect reported by Brizzolara et al. A closer look at the original study revealed that only 80 observations per child had been collected, which makes it probable that the larger IHTTs in 7-year-olds were caused by stimulus-response compatibility rather than by the lower efficiency of the corpus callosum during childhood years. E. RatinckxM. Brysbaertmarc.brysbaert@ugent.beG. d'Ydewalle1999-07-05Z2011-03-11T08:54:18Zhttp://cogprints.org/id/eprint/815This item is in the repository with the URL: http://cogprints.org/id/eprint/8151999-07-05ZCommentary on "What is consciousness?" by Mark Solms.The puzzle of how an "objectively real" brain might produce "subjectively real" experiences dissolves if experiences can be shown to be nothing more than (ontologically identical to) states of the brain. However, this form of reductionism cannot be made to work. Science may discover the neural causes and correlates of consciousness, but causation and correlation are very different to ontological identity. Solms suggests a solution to this puzzle which breaks down the classical "objective/subjective" distinction, and his proposals, informed by psychodynamic theory, are very close to ones I have developed in the effort to construct a phenomenologically-sensitive cognitive science. This involves a nonreductionist analysis of first- and third-person access to mental life, and a dual-aspect theory in which "subjective" conscious experiences and "objective" brain states are treated as two ways of viewing one, unfolding, mental life or thing-itself.Max. Velmans1998-08-03Z2011-03-11T08:53:38Zhttp://cogprints.org/id/eprint/54This item is in the repository with the URL: http://cogprints.org/id/eprint/541998-08-03ZDevelopmental changes in the theta response system: a single-sweep analysisRecently, increased interest was focused on the EEG frequency responses in the theta (4-7 Hz) range because of their association with stimulus information processing. However, it is not known whether the event-related theta response depends on the development of the spontaneous theta activity and how it varies with age in children. In the present study, a single-sweep analysis was applied to assess the developmental changes in the event-related EEG theta activity. Auditory passive, oddball target, and standard event-related potentials (ERPs) were recorded at Fz, Cz, and Pz from 50 children aged 6-11 years and 10 young adults. Theta responses were analyzed in two time windows of the post-stimulus epochs for three single-sweep parameters: amplitude, phase-locking with stimulus, and enhancement relative to prestimulus activity. For all three types of stimuli adults had theta responses with lower amplitude, higher enhancement, and stronger phase-locking than those of children. Unlike adults, no reliable differences between the early and late theta response were found for children. Significant developmental changes were observed for theta response amplitude that decreased and phase-locking of early theta responses that increased with advancing age. These findings indicate that the theta component of the auditory ERP differs remarkably between children and adults and undergoes developmental alterations, possibly reflecting specific differences in stimulus information processing.Juliana YordanovaVasil Kolev1998-08-20Z2011-03-11T08:53:38Zhttp://cogprints.org/id/eprint/59This item is in the repository with the URL: http://cogprints.org/id/eprint/591998-08-20ZDYNAMICS OF A RECURRENT NETWORK OF SPIKING NEURONS BEFORE AND FOLLOWING LEARNINGExtensive simulations of large recurrent networks of integrate-and-fire excitatory and inhibitory neurons in realistic cortical conditions (before and after Hebbian unsupervised learning of uncorrelated stimuli) exhibit a rich phenomenology of stochastic neural spike dynamics, and in particular, coexistence between two types of stable states: spontaneous activity, upon stimulation by an unlearned stimulus; and `working memory' states strongly correlated with learned stimuli. Firing rates have very wide distributions, due to the variability in the connectivity from neuron to neuron. ISI histograms are exponential, except for small intervals. Thus the spike emission processes are well approximated by a Poisson process. The variability of the spike emission process is effectively controlled by the magnitude of the post-spike reset potential relative to the mean depolarization of the cell. Cross-correlations (CC) exhibit a central peak near zero delay, flanked by damped oscillations. The magnitude of the central peak in the CCs depends both on the probability that a spike emitted by a neuron affects another randomly chosen neuron and on firing rates. It increases when average rates decrease. Individual CCs depend very weakly on the synaptic interactions between the pairs of neurons. The dependence of individual CCs on the rates of the pair of neurons is in agreement with experimental data. The distribution of firing rates among neurons is in very good agreement with a simple theory, indicating that correlations between spike emission processes in the network are effectively small.Daniel J. AmitNicolas Brunel1998-04-01Z2011-03-11T08:53:37Zhttp://cogprints.org/id/eprint/12This item is in the repository with the URL: http://cogprints.org/id/eprint/121998-04-01ZNeural mechanisms of timingA crucial step in timing research is to isolate clock components from other sources of temporal variability. Significant progress has been made both behaviorally and neurologically. More elaborate experimental designs have helped researchers separate timing mechanisms from motoric, sensory, and mnemonic processes. Marked similarities in the temporal characteristics of the clock in perception and production tasks implicate a common timing system. Similar conclusions can be reached from studies of patient populations: Individuals with neocerebellar damage are impaired at discriminating and reproducing short intervals. However, other patient populations, especially those with disorders affecting the basal ganglia, also exhibit deficits in timing tasks. Temporal computation may be distributed throughout the brain, but recent evidence suggests specific roles for different neural structures.Eliot HazeltineLaura L HelmuthRichard B Ivry2010-04-01T11:37:11Z2011-03-11T08:57:35Zhttp://cogprints.org/id/eprint/6810This item is in the repository with the URL: http://cogprints.org/id/eprint/68102010-04-01T11:37:11ZNeuropragmatics: Neuropsychological constraints on formal theories of dialogueWe are interested in the validation of a cognitive theory of human communication, grounded in a speech acts perspective. The theory we refer to is outlined, and a number of predictions are drawn from it. We report a series of protocols administered to 13 brain-injured subjects and to a comparable control group. The tasks included direct and indirect speech acts, irony, deceits, failures of communication, and theory of mind inferences. All the predicted trends of difficulty are consistently verified; in particular, difficulty increases from direct/indirect speech acts to irony, from irony to deceits, and from deceits to failure recovery. This trend symmetrically shows both in the successful situation and in the failure situation. Further, failure situations prove more difficult to handle than the relevant successful situation. In sharp contrast with previous literature, there is no difference between the subjects' comprehension of direct and indirect speech acts. The results are discussed in the light of our theoretical approach.Bruno G. BaraMaurizio Tirassamaurizio.tirassa@unito.itMarina Zettin2000-12-08Z2011-03-11T08:54:27Zhttp://cogprints.org/id/eprint/1143This item is in the repository with the URL: http://cogprints.org/id/eprint/11432000-12-08ZThe problems of inattention: methods and interpretations. (Editorial)NoneR. D. OADESG. SARTORY2000-12-04Z2011-03-11T08:54:27Zhttp://cogprints.org/id/eprint/1138This item is in the repository with the URL: http://cogprints.org/id/eprint/11382000-12-04ZStimulus dimension shifts in patients with schizophrenia, with and without paranoid hallucinatory symptoms, or obsessive compulsive disorder: strategies, blocking and monoamine statusIntroduction: Reversal and intra-dimensional (ID) and extra-dimensional (ED) non-reversal shifts in task discrimination learning were compared. The aim was to see if "learned inattention" to the irrelevant dimension differentially influenced the efficacy of learning and of the stimulus choice strategy. (An overall indicator of monoamine metabolism was measured for potential congruence between switches of attention and dopamine activity: see Oades, Neurosci. Biobehav. Rev., , 9, 261-283, 1985).
Methods: Performance on pattern-discrimination discrimination shifts was compared with conditioned blocking (CB: another test of "learned inattention") and related to the status of monoamine neurotransmitter metabolism reflected in 24h-urine samples between tests. Results are reported for 29 healthy subjects (mean age 18.0y), 13 patients with obsessive compulsive disorder (OCD: mean age16.3y), and 28 with schizophrenia, including 14 paranoid hallucinatory (PH: 19.6y) and 14 nonparanoid patients (NP: 17.5y).
Results:
1. PH and NP patients improved learning with practice but showed an impaired shift on each task.
2. Unlike PH and control subjects, the NP shift impairment was non-specific and related to their problems on simple reversal of the discrimination.
3. The length of the stimulus-response sequences showed that all subjects were able to acquire a set for colour.
4. An analysis of choice on sequential pairs of stimuli showed that while all patients showed fewer win-stay sequences, only PH patients perseverated with lose-stay sequences. This type of error in PH patients contrast with the increase of win-shift errors in NP patients (figure 1).
5. Learning about the added stimulus on the CB task related to the efficiency of intra-dimensional shift in NP patients.
6. An impairment with OCD patients was restricted to the ED-shift (not reversal or ID-shift).
7. Increases of dopamine activity related to slower initial learning, but to more switches (and rapid learning) on all shift tasks: (positive correlations with win/lose-shift, negative with win-stay). NA activity in PH and NP patients related to increased win-stay and decreased lose-shift decisions (figure 1).
8. Increased serotonin activity correlated with faster learning in controls, OCD and PH patients. But the opposite relationships for dopamine and serotonin activity held for NP patients (figure 2).
Conclusions:
The different tasks of the "learned inattention" paradigm have different if related requirements and correlates. The monoamine data are consistent with the postulated function of noradrenaline in tuning and dopamine in switching operations. The behavioural data are consistent with the automatization of endogenous information processing, while NP patients use exogenous attentional strategies fir selecting information and PH patients show inefficient endogenous control of attention.
Robert D. OADES1999-09-29Z2011-03-11T08:53:41Zhttp://cogprints.org/id/eprint/119This item is in the repository with the URL: http://cogprints.org/id/eprint/1191999-09-29ZTACIT INTEGRATION AND REFERENTIAL STRUCTURE IN THE LANGUAGE COMPREHENSION OF APHASICS AND NORMALSAphasics, brain damaged patients with no language deficit, neurologically intact elderly subjects and university undergraduates matched pictures to sentences having compelling tacit implications (e.g. the sentence The fox grabs the hen strongly invites one to assume that the fox will eat the hen). All groups made, for the same sentences, qualitatively similar referential errors consisting in choosing a tacit implication picture. Two auxiliary experiments using the same target sentences in other interpretive situations permitted ruling out the possibility that these errors were due to the putative intrinsic semantic properties of the sentences, showing that the sentences which were most liable to elicit integrative error varied from task to task. These results are interpreted within the conceptual framework which posits that reliable directions for interpretation are couched by the speaker in the very structure of his utterances (the utterance's referential structure) providing the hearer with means to restructure the relevant personal knowledge integrated into the interpretive process in accordance with the speaker's communicative intent. The determination of the referential structure (RSD) of utterances thus seems critical to their correct or, more precisely, conventional interpretation, and, along with the tacit integration of relevant sources of personal knowledge, constitutes the principal cognitive device enabling us to understand each other. But this device appears to be easily corruptible. It is suggested that many errors made by aphasics in language interpretation are due to a failure to follow all referential instructions, but that qualitatively similar failures also occur in normal subjects, though to a lesser degree. Language interpretation is a fallible process and aphasic errors provide remarkable clues for the understanding of its subtle referential mechanisms.Victor RosenthalPatrizia Bisiacchi1999-06-11Z2011-03-11T08:53:39Zhttp://cogprints.org/id/eprint/86This item is in the repository with the URL: http://cogprints.org/id/eprint/861999-06-11ZBrain size: a possible source of interindividual variability in corpus callosum morphologyThe corpus callosum (CC) is the main fiber tract connecting the cerebral hemispheres, and it has been estimated that about 200-350 million fibers run through this structure in the human brain (1,2). The CC seems to be important in the transfer and facilitation of associative information between the hemispheres. It is thought that the cross-sectional size of the CC may indicate the number of fibres crossing through (1), implying that a larger callosal area may indicate a higher capacity for interhemispheric transfer. Because the midsagittal CC size is so easy to measure either in post mortem material or on magnetic resonance images (MRI) it is one of the human brain structures to receive particular attention. There is some evidence suggesting that the morphology of the CC may be related to language dominance (13,14), gender (19), handedness (71,73-75), Down`s syndrom (68), dysphasia (51), schizophrenia (76), and dyslexia (32). The sometimes conflicting results in CC morphology were interpreted in two ways. The common interpretation has been that a larger CC midsagittal area (total CC or CC subarea) reflects increased interhemispheric connectivity resulting in (or due to) increased ambilaterality (73). This interpretation is at variance with the interpretation by Clarke and Zaidel (13) that the CC size indicates the amount of fibers inhibiting or interfering processes located in the dominant hemisphere. In the light of these controversies and with respect to the enormous variability in CC size across the subgroups tested, we employed whole-brain in-vivo magnetic resonance morphometry in order to investigate the anatomical relationship between CC midsagittal size and forebrain volume (FBV). This approach may also provide an empirical evaluation of the recently suggested relationship between brain size and lateralization (61) and it might help to explain the large interindividual variability in callosal size. In particular, we were interested to answer the following questions: (i) Is there an allometric relation between callosal size and brain size; (ii) If there is a relation between callosal size and brain size does this relation follow a geometrical rule?; (iii) Is there a true influence of gender? and ( iv); Is handedness or brain lateralization related to callosal size?L. JänckeH. Steinmetz1998-06-16Z2011-03-11T08:53:38Zhttp://cogprints.org/id/eprint/41This item is in the repository with the URL: http://cogprints.org/id/eprint/411998-06-16ZConceptual coordination: Abstraction without description.Conceptual coordination is a learning process that relates multiple perceptual-motor modalities (verbal, visual, gestural, etc.) in time. Lower-order categorizations are thus related by sequence and simultaneity, as shown by neurological dysfunctions. Heretofore, many theories of abstraction have only considered verbal behavior and assumed that the neural mechanism itself consists of manipulation of descriptions (linguistic models of the world and behavior). This broader view better relates physical and intellectual skills.William J. Clancey1998-06-15Z2011-03-11T08:54:12Zhttp://cogprints.org/id/eprint/687This item is in the repository with the URL: http://cogprints.org/id/eprint/6871998-06-15ZHemispheric independence in word recognition: evidence from unilateral and bilateral presentationsWe compared behavioral laterality effect in a lexical decision task using cued unilateral or bilateral presentations of different stimuli to normal subjects. The goals were to determine the effects of lexical variables on word recognition in each hemisphere under conditions of maximal independence of information processing in the two hemispheres and to assess the degree of residual interhemispheric effects that can still exist then. Bilateral presentations increased hemispheric independence in word recognition, indexed by a significant interaction of response hand with target visual field. Bilateral presentations also selectively impaired word decisions, suggesting that word processing benefits from interhemispheric interaction, whereas nonword processing is done independently in each hemisphere. Indeed, there was a significant congruity effect for word targets only, whereby the wordness of the unattended stimulus affected the speed of processing of attended word targets. Word frequency and regularity affected both hemispheres equally, arguing against the hemispheric interpretation of the dual route model of word recognition. Length affected the processing of nonwords more than words and in the LVF more than in the RVF. Taken together, the data support the conclusion that each normal hemisphere can control word recognition independently of the other.M. IacoboniE. Zaidel1998-06-22Z2011-03-11T08:54:12Zhttp://cogprints.org/id/eprint/703This item is in the repository with the URL: http://cogprints.org/id/eprint/7031998-06-22ZTowards a Design-Based Analysis of Emotional Episodeshe design-based approach is a methodology for investigating mechanisms capable of generating mental phenomena, whether introspectively or externally observed, and whether they occur in humans, other animals or robots. The study of designs satisfying requirements for autonomous agency can provide new deep theoretical insights at the information processing level of description of mental mechanisms. Designs for working systems (whether on paper or implemented on computers) can systematically explicate old explanatory concepts and generate new concepts that allow new and richer interpretations of human phenomena. To illustrate this, some aspects of human grief are analysed in terms of a particular information processing architecture being explored in our research group. We do not claim that this architecture is part of the causal structure of the human mind; rather, it represents an early stage in the iterative search for a deeper and more general architecture, capable of explaining more phenomena. However even the current early design provides an interpretative ground for some familiar phenomena, including characteristic features of certain emotional episodes, particularly the phenomenon of perturbance (a partial or total loss of control of attention). The paper attempts to expound and illustrate the design-based approach to cognitive science and philosophy, to demonstrate the potential effectiveness of the approach in generating interpretative possibilities, and to provide first steps towards an information processing account of `perturbant', emotional episodes.Ian WrightAaron SlomanLuc Beaudoin1998-06-15Z2011-03-11T08:53:38Zhttp://cogprints.org/id/eprint/40This item is in the repository with the URL: http://cogprints.org/id/eprint/401998-06-15ZAnticipation and feeling in literary response: A neuropsychological perspectiveAnticipation and feeling are taken to be significant components of the process of literary reading, although cognitive theories of reading have tended to neglect them. Recent neuropsychological research is described that casts light on these processes: the paper focuses on the integrative functions of the prefrontal cortex responsible for anticipation and on the contribution of feeling to the functions of the right cerebral hemisphere. It is shown how feelings appear to play a central role in initiating and directing the interpretive activities involved in such complex activities as reading. In particular, a key feature of literary texts that captures and directs response is foregrounding, that is, distinctive stylistic features: these defamiliarize and arouse feeling. Such responses are likely to be mediated by the right hemisphere, which is specialized to process novelty. An analysis of the neuropsychological mechanisms implicated in response to foregrounding suggests how readers discriminate among competing interpretive possibilities, and how other important elements of literary response such as imagery, memory, and self-referential themes and concerns are recruited. Several studies are cited indicating that response to various characteristic components of literary texts is mediated by this hemisphere, including the prosodic aspects of foregrounding, figurative language, and narrative structure. This hemisphere also provides the context for elaborating and contextualizing negative feelings, a process related to Aristotle's notion of catharsis. It is argued that the neuropsychological evidence sketched in this paper provides a more reliable basis for future theoretical and empirical studies of literary reading.David S. Miall2000-08-14Z2011-03-11T08:54:22Zhttp://cogprints.org/id/eprint/935This item is in the repository with the URL: http://cogprints.org/id/eprint/9352000-08-14ZPhysiological responses to verbally inaccessible pictorial information in the left and right hemispheres. NeuropsychologyWe investigated the effects of very brief pictorial information on transfer between the cerebral hemispheres through recordings of skin conductance responses. The pictorial stimuli had been judged previously as "neutral", "positive", or "negative" by an independent group of subjects. The verbally-available stimuli (VA) were neutral whereas the very brief, verbally-unavailable stimuli (VU) were positive or negative. The VA and VU stimuli were presented simultaneously, either in the same visual half-field (intra-hemispheric interference) or in the opposite visual half-field (inter-hemispheric interference). In a third condition, there were only VA stimuli in either visual field (no interference). We found that the right hemisphere was especially sensitive to negative VU presentations, both in the inter-and intra-hemispheric interference groups. The left hemisphere showed a corresponding sensitivity to positive interference, but only in the inter-hemispheric interference group. These findings confirm the hemispheric roles in mediating positive versus negative emotions and they show that in the interplay between hemispheric specialization and commissural transfer, left to right transfer can take place without linguistic cognition.
Dahlia W. ZaidelKenneth HugdahlBjoern Helge Johnsen2000-08-15Z2011-03-11T08:54:22Zhttp://cogprints.org/id/eprint/919This item is in the repository with the URL: http://cogprints.org/id/eprint/9192000-08-15ZThe case for a relationship between human memory, hippocampus and corpus callosumUnilateral brain damage which includes the hippocampus leads to memory impairments consistent with hemispheric specialization on the same side. Damage to the corpus callosum, the major connecting pathway between the left and right hemispheres, also leads to memory impairments. This suggests both hemispheric specialization on the hippocampal level and a critical role for the corpus callosum in memory functions. A complete hippocampal formation is present on either side of the brain but traditionally only one is studied. However, a comparison between the neuronal populations in the hippocampus on both sides revealed asymmetry in connectivity among hippocampal subfields. The profile of memory impairments of commissurotomy (split-brain) patients is described. The results are discussed in terms of a relationship between hippocampus and corpus callosum in humans. As hemispheric specialization evolved, inter-hippocampal connections became less important and the corpus callosum became prominent in memory functions.
Dahlia W. Zaidel2000-01-31Z2011-03-11T08:53:41Zhttp://cogprints.org/id/eprint/133This item is in the repository with the URL: http://cogprints.org/id/eprint/1332000-01-31ZEEG coherence has structure in the millimeter domainSubdural recordings from 8 patients via rows of eight electrodes with either 5 or 10 mm spacing plus depth recordings from 3 patients with rows of 8-12 electrodes either 6.5 or 9 mm center-to-center were searched for signs of significant local differentiation of coherence calculated between all possible pairs of loci. EEG samples of 2-4 min were taken during four states: alertness, stage 2-3 sleep, light surgical anesthesia permitting the patient to respond to questions or commands, and electrical seizures. Coherence was computed for all frequencies from 1-50 Hz or 0.3-100 Hz and then compared for 6 or 7 narrower bands between 2 and 70 Hz. In both the subdural surface samples and those from temporal lobe depth electrode arrays coherence declines with distance between electrodes of the pair, on the average. This is nearly the same for all frequency bands. Whether computed for 5, 20 or 60 s epochs, coherence pooled across all pairs of a given separation, in a given subject, differs only slightly, in the direction of lower coherence for longer samples, indicating good stationarity of the samples chosen. For middle bands like 8-13 and 13-20 Hz, mean coherence typically declines most steeply in the first 10 mm, from values indistinguishable from 1.0 at <0.5 mm distance to 0.5 at 5-10 mm and to 0.25 in another 10-20 mm in the subdural surface data. Temporal lobe depth estimates decline ca. half as fast; coherence 0.5 extends for 9-20 mm and 0.25 for another 20-35 mm. Low frequency bands (1-5, 5-8 Hz) usually fall slightly more slowly than high frequency bands (20-35, 35-50 Hz) but the difference is small and variance large. The steepness of decline with distance in humans is significantly but only slightly smaller than that we reported earlier for the rabbit and rat, averaging < one half. Local coherence, for individual pairs of loci, shows differentiation in the millimeter range, i.e. nearest neighbor pairs may be locally well above or below average and this is sustained over minutes. Local highs and lows tend to be similar for widely different frequency bands. Coherence varies quite independently of power, although they are sometimes correlated. Regional differentiation is statistically significant in average coherence among pairs of loci on temporal vs frontal cortex or lateral frontal vs subfrontal strips in the same patient, but such differences are usually small. We could not test how consistent they are over hours or between patients. Differences between left and right hemispheres, whether symmetrical pairs or pooled from two or more lobes on each side, can be quite large; in our patients the right side is usually higher, especially in the waking state. Brain state has a large influence. Slow wave sleep usually shows slightly more coherence at each distance, in all bands, compared to the waking EEG, but not consistently. Coherence at a given distance or its rate of decline with distance is a more direct measure of synchrony than naked-eye "synchronization," which is dominated by the power spectrum. Among the range of EEG states classified as seizures, coherence varies widely but averages higher by 0.05-0.2 than in pre-ictal states, usually in all frequencies when computed over the whole seizure but much more in the higher bands during the height of the electrical paroxysm. The findings point to still finer structure and more variance with closer spacing of electrodes. They could not predict the known large scale coherence between scalp electrodes, but are not in conflict with them. Scalp recording blurs the finer spatial structure, but reveals macrostructure missed by subdural and depth recording with limited numbers of channels. The strong tendency for correlated fluctuations across frequency bands is contrary to expectation from the common model of independent oscillators.T.H. BullockM. McCluneJ. AchimowiczIragui-Madoz V.J.Duckrow R.B.Spencer S.S.1999-04-13Z2011-03-11T08:53:52Zhttp://cogprints.org/id/eprint/380This item is in the repository with the URL: http://cogprints.org/id/eprint/3801999-04-13ZThe investigation of consciousness through phenomenology and neuroscienceThe principal problem of consciousness is how brain processes cause subjective awareness. Since this problem involves subjectivity, ordinary scientific methods, applicable only to objective phenomena, cannot be used. Instead, by parallel application of phenomenological and scientific methods, we may establish a correspondence between the subjective and the objective. This correspondence is effected by the construction of a theoretical entity, essentially an elementary unit of consciousness, the intensity of which corresponds to electrochemical activity in a synapse. Dendritic networks correspond to causal dependencies between these subjective units. Therefore, the structure of conscious experience is derived from synaptic connectivity. This parallel phenomenal/neural analysis provides a framework for the investigation of a number of problems, including sensory inversions, the unity of consciousness, and the nature of nonhuman consciousness.Bruce J. MacLennan1999-07-22Z2011-03-11T08:53:40Zhttp://cogprints.org/id/eprint/110This item is in the repository with the URL: http://cogprints.org/id/eprint/1101999-07-22ZNeural Integration at the Mesoscopic Level: the Advent of some Ideas in the Last Half CenturyHistory seen by a professional historian, based only on the documented record, always incomplete and liable to bias, can be unreliable. Modern history seen by a protagonist must surely be among the most unreliable. My only excuse for this effort is that I was invited by the relevant Society committee. My reason for accepting is that I feel even the fragmentary part of neuroscience I can speak about is a human drama, romantic and exciting, and a flood on which we are floating, unable to dump the baggage of past biases. Our points of view, priorities, and positions on all the controversial issues and even the well established, noncontroversial ones, are not as rational as we would like to think but are strongly conditioned by where we came from. I will depend mainly on selected vignettes of the way things looked when I was a student, a young postdoctoral fellow and an Assistant Professor, to compare with the way they look to me or to others now, in each of half a dozen mesoscopic domains. I mean by mesoscopic domains the middle levels - those in between the most basic subcellular or molecular and the higher levels of learning and cognition. The half dozen domains constitute of course, anything but a representative fraction of neuroscience. I believe, however, that they add up to a nontrivial segment of the big picture with respect to the integrative aspects of our science. Most of the fronts that grew into today's popular branches of our science are not represented but a small set of particular interest and probability of further surprises.Theodore H. Bullock1998-06-16Z2011-03-11T08:53:49Zhttp://cogprints.org/id/eprint/323This item is in the repository with the URL: http://cogprints.org/id/eprint/3231998-06-16ZA tutorial on situated learning.The theory of situated learning claims that every idea and human action is a generalization, adapted to the ongoing environment, because what people see and what they do arise together. From this perspective, thinking is a physical skill. As we create names for things, shuffle around sentences in a paragraph, and interpret what our statements mean, every step is controlled not by reinstantiated grammars and previously constructed plans, but adaptively recoordinated from previous ways of seeing, talking, and moving. Situated learning is the study of how human knowledge develops in the course of activity, and especially how people create and interpret descriptions (representations) of what they are doing. This introduction provides a historical perspective of situated learning, including the work of Dewey, Bartlett, Vygotsky, and Ryle. I provide examples of how situated learning is being applied today in business process redesign.William J. Clancey2000-08-13Z2011-03-11T08:54:22Zhttp://cogprints.org/id/eprint/923This item is in the repository with the URL: http://cogprints.org/id/eprint/9232000-08-13ZWorlds apart: Pictorial semantics in the left and right cerebral hemispheresThe dominant view in neuropsychology fails to consider that the
hemispheric "functional division of labor" in terms of language versus
non-language reflects but one dimension of hemispheric differences.
That is, specialization of language in the left hemisphere and of
spatial orientation in the right represent only specific aspects of the
general underlying hemispheric meaning systems. Indeed, we have found
that there can be two full-blown meaning systems, one in the left and
one in the right, which can operate separately and simultaneously in
the normal brain.
~
Dahlia W. Zaidel2004-04-07Z2011-03-11T08:55:30Zhttp://cogprints.org/id/eprint/3528This item is in the repository with the URL: http://cogprints.org/id/eprint/35282004-04-07ZBehavioral estimates of interhemispheric transmission time and the signal detection method: A reappraisalOn the basis of a review of the literature, Bashore (1981) concluded that only simple reaction time experiments with manual responses yielded consistent behavioral estimates of interhemispheric transmission time. A closer look at the data, however, revealed that these experiments were the only ones in which large numbers of observations were invariably obtained from many subjects. To investigate whether the methodological flaw was the origin of Bashore’s conclusion, two experiments were run in which subjects had to react to lateralized light flashes. The first experiment dealt with manual reactions, the second with verbal reactions. Each experiment included a condition without catch trials (i.e., simple reaction time) and two conditions with catch trials. Catch trials were trials in which no stimulus was given and in which the response was to be withheld. Both experiments returned consistent estimates of interhemispheric transmission time in the range of 2–3 msec. No differences were found between the simple reaction time condition and the signal detection conditions with catch trials. Data were analyzed according to the variable criterion theory. This showed that the effect of catch trials, as well as the effect of interhemispheric transmission, was situated at the height of the detection criterion, and not in the rate of the information transmission.Marc Brysbaert1998-06-15Z2011-03-11T08:53:38Zhttp://cogprints.org/id/eprint/39This item is in the repository with the URL: http://cogprints.org/id/eprint/391998-06-15ZCallosal transmission time before and after partial commissurotomyInterhemispheric transmission time was measured in a patient before and after partial commissurotomy sparing the splenium of the corpus callosum. The transmission time was measured using a simple reaction time paradigm with unimanual responses to lateralized flashes at 4 and 8 degrees of eccentricity. Post-operative transfer time was longer than pre-operative transfer time at 8 degrees but not at 4 degrees of eccentricity. These data do not support the notion that the callosal transfer time is always faster through motor rather than visual fibers. They rather suggest that the callosal transfer time through visual fibers is longer than the callosal transfer time through motor fibers only for flashes at large eccentricities.M. IacoboniI. FriedE. Zaidel1999-11-16Z2011-03-11T08:53:41Zhttp://cogprints.org/id/eprint/124This item is in the repository with the URL: http://cogprints.org/id/eprint/1241999-11-16ZDynamics of event-related potentials to trains of light and dark flashes: responses to missing and extra stimuli in elasmobranch fish.To characterize the dependencies of ERPs in lower vertebrates and brain levels upon recent history and sequences of stimuli, trains of flashes were delivered at various frequencies to unanesthetized rays while recording in optic tectum and telencephalon. ERPs to repetitive stimuli cannot be understood in terms of simple refractoriness and recovery. Processes must be invoked such as simultaneous excitation and suppression, facilitation and its opposite, rebound and induced rhythms, each with development and decay times and nonlinearities. Some of these processes are uncovered by omitting a stimulus from a train. Omitted stimulus potentials (OSPs) act as though the brain expects a stimulus within 5-7 ms of the interstimulus interval (ISI) of the train. Very few ISIs suffice. The effect upon VEP form and duration of the number of stimuli in short trains, before the steady state response (SSR) is established, is complex. Alternation of the amplitude of successive VEPs (1 large every 2 VEPs, 1 in 3, 1 in 4) is one indication of complexities in the SSR. OSPs also alternate. A single extra stimulus interpolated into a regular train causes distinct effects according to its position. Sharp discontinuities in these effects appear with <5 ms shifts. Total power of the SSR decreases with stimulation frequency but there is a large peak of increased power at 7 Hz and another at 12 Hz. Induced rhythms are a labile, late phase of OSPs as well as of rested VEPs and of the OFF response to a long light pulse. Jittered ISI experiments show that the apparent expectation of the OSP is little affected and that the intervals in the last few hundred milliseconds are most influential. The OSP studied here (ISI <0.5 s)is quite different from that so far studied in human subjects (ISI >1s). We predict further similarities when each taxon is tested in the other ISI range. A major category of response characteristics, besides sensitivity, receptive fields and recovery times, is dependence upon recent history of iterative events, including intervals, delays, omissions and perhaps multiple facilitating and forgetting time constants. The variables examined parametrically in this study are only some of those available. Such dynamical characteristics are important neglected properties of afferent systems at each level.Sacit KaramürselT.H. Bullock2000-08-16Z2011-03-11T08:54:23Zhttp://cogprints.org/id/eprint/938This item is in the repository with the URL: http://cogprints.org/id/eprint/9382000-08-16ZMemory for faces in epileptic children before and after brain surgeryMemory for pairs of unfamiliar children's faces was investigated in 29 children and adolescents suffering from left (LTLE) or right (RTLE) temporal-lobe epilepsy, before and after temporal-lobe surgery. Both immediate and delayed memory were tested. Before surgery, RTLE subjects performed worse than either LTLE subjects or normal children. After surgery, RTLE subjects improved significantly. Overall (after surgery), there was no significant LTLE-RTLE difference, but on delayed memory, the RTLE group was worse than the LTLE group. The results suggest specialization for facial memory in the right hemisphere of young patients, as in adults, despite early brain damage. Elizabeth D. BeardsworthDahlia w. Zaidel1998-03-12Z2011-03-11T08:54:07Zhttp://cogprints.org/id/eprint/613This item is in the repository with the URL: http://cogprints.org/id/eprint/6131998-03-12ZPersonality and lipid level differences associated with homosexual and bisexual identity in menBisexuality is thought by many to be an intermediate sexual orientation on a continuum between the more exclusive extremes of heterosexuality and homosexuality. Kinsey et al. (1948) adopted this assumption in devising their scale of sexual orientation, which assigned seven anchored points along what they saw as a continuum of behavior from exclusively homosexual (HS) to exclusively heterosexual (HT).Peter J SnyderJames D WeinrichRichard C Pillard2000-08-19Z2011-03-11T08:54:23Zhttp://cogprints.org/id/eprint/942This item is in the repository with the URL: http://cogprints.org/id/eprint/9422000-08-19ZSex of the face in Western art: Left and right in portraitsThe relationship between observers' taste and the sitter's face orientation as function of sitter sex in painted portraits was investigated. The historical tendency in portraiture is that the sitter's left side of the face is more likely than the right to be turned towards the viewer and this side bias is stronger with women than with men. Correctly oriented and reversed museum portraits were viewed by subjects who gave ratings of "liking" the portrait as a whole (Experiment 1) and for "attractiveness" of the sitter (Experiment 2). Only portraits of women showed a left-right difference with right favored significantly over left, irrespective of orientation or type of rating. These findings go against the historical pattern of the sex-related bias in portraiture. They suggest that most women are painted in an orientation which is less favorable to them. Dahlia W. ZaidelPeter FitzGerald2000-08-13Z2011-03-11T08:54:22Zhttp://cogprints.org/id/eprint/920This item is in the repository with the URL: http://cogprints.org/id/eprint/9202000-08-13ZA view of the world from a split-brain perspectiveThe extent to which observed behavior in the complete commissurotomy
patients is supported by only one hemisphere would depend on individual
differences interacting with a variety of factors such as genetics,
intelligence, and so on. The lesson imparted here is that there is
sufficient functional redundancy in the neocortex so that the capacity
to maintain a wide range of abilities is within the control of one
hemisphere. And, yet, as seen in what is missing in the patients'
behavior, one hemisphere is not quite enough. Nature seems to have
intended that the two hemispheres complement each other, that the full
range of human behavior be best accomplished through interaction
between the left and right hemispheres.Dahlia W. Zaidel1998-12-21Z2011-03-11T08:53:39Zhttp://cogprints.org/id/eprint/73This item is in the repository with the URL: http://cogprints.org/id/eprint/731998-12-21ZA Neural Attentional Model for Access to Consciousness: A Global Workspace PerspectiveA broad consensus has developed in recent years in the cognitive and neurosciences that the cognitive functions of the mind arise out of the activities of an extensive and diverse array of specialized processors operating as a parallel, distributed system. A theoretical perspective is presented which expands upon this "society" model to include globally integrative infuences upon this arrary of processors. This perspective serves as the basis for an explicit neural model of a "global workspace within a system of distributed specialized processors". Anatomical and physiological evidence are reviewed which suggest that this parallel, modular architecture is superceded by a more diffuse, tangential intracortical network capable of integrating underlying modular activites into increasingly global cognitive representations. There follows an explication of the role of this "neural global workspace" in providing the essential basis for the central control of attention and the generation of unified, conscious percepts. Finally the role of thalamic and brainstem activation systems in these integrative processes is discussed.James NewmanBernard J. Baars1998-06-16Z2011-03-11T08:53:58Zhttp://cogprints.org/id/eprint/459This item is in the repository with the URL: http://cogprints.org/id/eprint/4591998-06-16ZSituated action: A neuropsychological interpretation (Response to Vera and Simon)Symbols in computer programs are not necessarily isomorphic in form or capability to neural processes. Representations in our models are stored descriptions of the world and human behavior, created by a human interpreter; representations in the brain are neither immutable forms nor encoded in some language. Although the term "symbol" can be usefully applied to describe words, smoke signals, neural maps, and graphic icons, a science of symbol processing requires distinguishing between the structural, developmental, and interactive nature of different forms of representing.William J. Clancey1998-06-15Z2011-03-11T08:54:11Zhttp://cogprints.org/id/eprint/685This item is in the repository with the URL: http://cogprints.org/id/eprint/6851998-06-15ZLearning as social and neural.Representations are created and given meaning in a shared perceptual space, where they are spoken, written, and drawn in the context of social activity. Consequently, problems in science education cross the boundaries of traditional modularization of the mind into separate perceptual, representation, and communication components that act at distinct times, in distinct domains. We illustrate these issues with a case study of physics learning using a simulation program. The learners are initially uncertain about what aspects of motion to see, where the representations are on the screen, and how to express the relationship between vector notation and motion. At a local level, the students jointly coordinate conversational and perception-action processes to maintain a mutually intelligible stream of activity. At a slightly broader level, they use perception, language, and gesture to construct a shared understanding of what the notation on the computer screen means. Even more broadly, the students use their understanding of the notation to relate their activity to ways in which scientists address similar situations. We conclude that learning to make sharp distinctions from a repertoire of fuzzy, everyday descriptions requires simultaneous, coordination of perception, gesture, and language; one cannot assume competence in two areas and analyze only the third.J. RoschelleWilliam J. Clancey1998-06-24Z2011-03-11T08:53:49Zhttp://cogprints.org/id/eprint/335This item is in the repository with the URL: http://cogprints.org/id/eprint/3351998-06-24ZThe biology of consciousness: Comparative review of Israel Rosenfield, The Strange, Familiar, and Forgotten: An anatomy of Consciousness and Gerald M. Edelman, Bright Air, Brilliant Fire: On the Matter of the MindFor many years, most AI researchers and cognitive scientists have reserved the topic of consciousness for after dinner conversation. Like "intuition," the idea of consciousness appeared to be too vague or general to be a good starting place for understanding cognition. Work on narrowly-defined problems in specialized domains such as medicine and manufacturing focused our concerns on the nature of representation, memory, strategies for problem-solving, and learning. Some writers, notably Ornstein(1972) and Hofstadter (1979), continued to explore the ideas, but implications for cognitive modeling were unclear, suggesting neither experiments, nor new computational mechanisms.W J. Clancey1998-04-30Z2011-03-11T08:53:57Zhttp://cogprints.org/id/eprint/443This item is in the repository with the URL: http://cogprints.org/id/eprint/4431998-04-30ZReview of Rosenfield's "The Invention of Memory"Evidence collected by Bartlett, Collingwood, James, Bransford, Jenkins, and Sacks argues against the memory-as-stored-structures hypothesis, the keystone of expert systems and cognitive modeling research.William J. Clancey2010-09-13T03:48:42Z2011-03-11T08:57:45Zhttp://cogprints.org/id/eprint/7024This item is in the repository with the URL: http://cogprints.org/id/eprint/70242010-09-13T03:48:42ZIndividual analysis of laterality dataGraphical and statistical analyses are presented that allow one to check for an individual subject whether the performance during a session is stable. whether the difference between the left and the right visual half-field is significant. and whether the performance is uniform over different sessions. Analyses are given for accuracy data and for latency data. Though the analyses are described for a visual half-field experiment, they can easily be adapted for other laterality tasks.M. Brysbaertmarc.brysbaert@ugent.beG. d'Ydewalle2010-09-13T03:48:51Z2011-03-11T08:57:44Zhttp://cogprints.org/id/eprint/7023This item is in the repository with the URL: http://cogprints.org/id/eprint/70232010-09-13T03:48:51ZTachistoscopic presentation of verbal stimuli for assessing cerebral dominance: Reliability data and some practical recommendations.Reliability data point to rather high test-retest correlations (>.65) for VHF data with four- and live-letter words as stimuli, but replicate previous findings that the first test score correlates poorly with later test scores. The same results are obtained for accuracy and latency data, though small differences exist. All laterality indices lead to the same conclusions and have high intercorrelations. The point-biserial correlation coefficient is, however, a slightly more reliable index of naming latency than the mere difference between LVF and RVF. No such superiority is found for the indices based on accuracy data. The results also point to the need to present a sufficient number of stimuli before firm conclusions can be drawn.M. Brysbaertmarc.brysbaert@ugent.beG. d'Ydewalle2000-08-23Z2011-03-11T08:54:23Zhttp://cogprints.org/id/eprint/943This item is in the repository with the URL: http://cogprints.org/id/eprint/9432000-08-23ZHemispheric memory for surrealistic versus realistic paintingsThe issue of hemispheric processing of art works, either alone or in relation to a certain aspect of language, was investigated in normal subjects. Three experiments were performed. In the first, memory for surrealistic versus realistic pictures was investigated. In the second, memory for metaphoric versus literal titles of these pictures was measured. In the third, memory for the paintings was determined as a function of the same titles. The results of the first experiment showed a right visual field (RVF) advantage for the surrealistic pictures. No field difference emerged for the realistic pictures. The results of the second experiment indicated a RVF advantage in memory for metaphoric titles. Moreover, in the RVF, there was an advantage for titles from surrealistic-metaphoric pairs over all other pairings. Results of experiment three showed a RVF advantage in remembering pictures from surrealistic-metaphoric pairs and in the left visual field (LVF) there was advantage for pictures with literal titles. Taken together, the results suggest left hemisphere advantage in processing meaningful, yet incongruous arrays, both pictorial and linguistic. The results are discussed in terms of hemispheric memory for art works, metaphors, and the relationship between the two in the brain. Dahlia W. ZaidelAsa Kasher2001-01-24Z2011-03-11T08:54:29Zhttp://cogprints.org/id/eprint/1255This item is in the repository with the URL: http://cogprints.org/id/eprint/12552001-01-24ZEvent-related potentials in autistic and healthy children on an auditory choice reaction time taskIntroduction: Childhood autism can occur in 5 out of 10,000 of the population. The condition covers problems of sensory modulation, comprehension and communication as it relates to both objects and people. Of the stages of information processing recorded in auditory event-related potentials (ERPs), reductions of N1 and P3 amplitude have been reported in many situations, but an increased P3 response to non-targets may represent difficulties in attributing differentially significance to some but not all stimuli..
Methods: Recordings were derived from midline and 4 lateral sites on the scalp of 7 children with autism and 7/13 healthy control children matched for age (median 139 vs. 135 months). A three-tone oddball paradigm was presented in a passive and active-task form (72% at 1 kHz, 14% at 0.5 kHz and 14% at 2.0 kHz)
Results:
a) Autistic subjects showed twice as many errors of omission and a higher beta criterion (signal detection) for targets.
b) For autistic subjects N1 latencies were shorter and N1 amplitude larger to deviants (especially nontargets).
c) However, subtraction of the ERPs in nontarget from target conditions showed that the processing negativity (PN) and especially the Negative difference (Nd) was smaller in autistic subjects.
d) In contrast the P3 amplitude (especially after the target) was smaller in autistic subjects.
e) Within autistic subjects the topography showed more early negativity after deviants at left frontal sites and more target induced late positivity at right parietal sites.
Conclusions: The ERPs of autistic children were more responsive to stimulus features (high frequency or deviance) and less responsive to the stimulus associations (target features). The ERPs also provide conflicting signs of neurodevelopment, -- precocious in the right-hemispheric emphasis for P3, but delayed in that P3 was not maximal at parietal sites.
R.D. OadesM.K. WalkerL.B. GeffenL.M. Stern1998-04-25Z2011-03-11T08:53:37Zhttp://cogprints.org/id/eprint/22This item is in the repository with the URL: http://cogprints.org/id/eprint/221998-04-25ZThe brain as a Darwin MachineAMIDST all the hyperbole about thinking machines that has accompanied the emergence of large-scale parallel computers from their serial predecessors, we have begun to contemplate the prospect of simulating some of our brain's massive parallelism. But one immediately runs into a role reversal worthy of a Mozart opera: the most distinctively human higher brain functions are surprisingly serial.William H. Calvin2000-06-07Z2011-03-11T08:54:21Zhttp://cogprints.org/id/eprint/858This item is in the repository with the URL: http://cogprints.org/id/eprint/8582000-06-07ZLearning Theory and the Evolutionary AnalogyIn this article, past comparisons of learning and evolution as analogous processes are discussed and some inaccuracies and omissions in those discussions are pointed out. The evolutionary analogy is examined for its ability to suggest solutions to five fundamental theoretical issues about learning - superstitions, why a reinforcer has the effect it does, the relationship among various procedures yielding learning, the relevance of the matching law to the problem of what reinforces an avoidance response, and whether behavioral and cognitive views of learning can be reconciled. In each case it is argued that the analogy is instructive.Marion Blute2001-01-22Z2011-03-11T08:54:29Zhttp://cogprints.org/id/eprint/1247This item is in the repository with the URL: http://cogprints.org/id/eprint/12472001-01-22ZSelf recognition and social awareness in the deconnected minor hemisphereTwo patients with cerebral commissurotomy were tested with visual input lateralized to left or right half of the visual field by an opaque hemifield screen set in the focal plane of an optical system mounted on a scleral contact lens which allowed prolonged exposure and ocular scanning of complex visual arrays. Key personal and affect-laden stimuli along with items for assessing general social knowledgability were presented among neutral unknowns in visual arrays with 4-9 choices. Selective manual and associated emotional responses obtained from the minor hemisphere to pictures of subject's self, relatives, pets and belongings, and of public, historical and religious figures and personalities from the entertainment world revealed a characteristic social, political, personal and self-awareness comparable roughly to that of the major hemisphere of the same subject.Roger W. SperryEran ZaidelDahlia W. Zaidel2001-08-20Z2011-03-11T08:54:46Zhttp://cogprints.org/id/eprint/1757This item is in the repository with the URL: http://cogprints.org/id/eprint/17572001-08-20ZVision in a monkey without striate cortex: a case studyA rhesus monkey, Helen, from whom the striate cortex was almost totally removed, was studied intensively over a period of 8 years. During this time she regained an effective, though limited, degree of visually guided behaviour. The evidence suggests that while Helen suffered a permanent loss of 'focal vision' she retained (initially unexpressed) the capacity for 'ambient vision'.Nicholas K Humphrey