Cogprints: No conditions. Results ordered -Date, Title. 2018-01-17T14:22:36ZEPrintshttp://cogprints.org/images/sitelogo.gifhttp://cogprints.org/2012-11-09T19:46:17Z2013-02-18T15:15:33Zhttp://cogprints.org/id/eprint/8672This item is in the repository with the URL: http://cogprints.org/id/eprint/86722012-11-09T19:46:17ZMultivariate methods and small sample size: combining with small effect sizeThis manuscript is the author's response to: "Dochtermann, N.A. & Jenkins, S.H. Multivariate methods and small sample
sizes, Ethology, 117, 95-101." and accompanies this paper: "Budaev, S. Using principal components and factor analysis in animal behaviour research: Caveats and guidelines. Ethology, 116, 472-480"
Dr. Sergey V. Budaevsbudaev@gmail.com2009-04-21T02:38:44Z2011-03-11T08:57:21Zhttp://cogprints.org/id/eprint/6421This item is in the repository with the URL: http://cogprints.org/id/eprint/64212009-04-21T02:38:44ZThe Intentionality of Plover Cognitive StatesThis paper attempts to clarify and justify the attribution of mental states to animals by focusing on two different conceptions of intentionality: instrumentalist and realist. I use each of these general views to interpret and discuss the behavior and cognitive states of piping plovers in order to provide a substantive way to frame the question of animal minds. I argue that attributing mental states to plovers is warranted for instrumentalists insofar as it is warranted for similar human behavior. For realists about intentionality, the complexity, adaptability and flexibility of the plovers’ behavior, along with its ability to utilize the content of its representations and to satisfy the conditions of concept attribution, justifies attributing intentionality to plovers. Getting clearer on what is meant by animal minds, provides a better idea of what to look for in animal behavior. In many respects, investigating such phenomena is similar to investigations in other sciences.Chuck Stiegstie0076@umn.edu2008-01-30T15:48:26Z2011-03-11T08:57:03Zhttp://cogprints.org/id/eprint/5917This item is in the repository with the URL: http://cogprints.org/id/eprint/59172008-01-30T15:48:26ZHow training and testing histories affect generalization: a test of simple neural networks We show that a simple network model of associative learning can
reproduce three findings that arise from particular training and
testing procedures in generalization experiments: the effect of 1)
``errorless learning'' and 2) extinction testing on peak shift, and
3) the central tendency effect. These findings provide a true test
of the network model, which was developed to account for other
penhomena, and highlight the potential of neural networks to study
phenomena that depend on sequences of experiences with many stimuli.
Our results suggest that at least some such phenomena, e.g.,
stimulus range effects, may derive from basic mechanisms of
associative memory rather than from more complex memory processes.Stefano Ghirlandastefano.ghirlanda@unibo.itMagnus Enquist2006-11-07Z2011-03-11T08:56:42Zhttp://cogprints.org/id/eprint/5251This item is in the repository with the URL: http://cogprints.org/id/eprint/52512006-11-07ZSymbols are not uniquely humanModern semiotics is a branch of logics that formally defines symbol-based communication. In recent years, the semiotic classification of signs has been invoked to support the notion that symbols are uniquely human. Here we show that alarm-calls such as those used by African vervet monkeys (Cercopithecus aethiops), logically satisfy the semiotic definition of symbol. We also show that the acquisition of vocal symbols in vervet monkeys can be successfully simulated by a computer program based on minimal semiotic and neurobiological constraints. The simulations indicate that learning depends on the tutor-predator ratio, and that apprentice-generated auditory mistakes in vocal symbol interpretation have little effect on the learning rates of apprentices (up to 80% of mistakes are tolerated). In contrast, just 10% of apprentice-generated visual mistakes in predator identification will prevent any vocal symbol to be correctly associated with a predator call in a stable manner. Tutor unreliability was also deleterious to vocal symbol learning: a mere 5% of “lying” tutors were able to completely disrupt symbol learning, invariably leading to the acquisition of incorrect associations by apprentices. Our investigation corroborates the existence of vocal symbols in a non-human species, and indicates that symbolic competence emerges spontaneously from classical associative learning mechanisms when the conditioned stimuli are self-generated, arbitrary and socially efficacious. We propose that more exclusive properties of human language, such as syntax, may derive from the evolution of higher-order domains for neural association, more removed from both the sensory input and the motor output, able to support the gradual complexification of grammatical categories into syntax.Sidarta RibeiroAngelo LoulaIvan AraújoRicardo GudwinJoao Queiroz2006-12-12Z2011-03-11T08:56:44Zhttp://cogprints.org/id/eprint/5298This item is in the repository with the URL: http://cogprints.org/id/eprint/52982006-12-12ZRetrospective revaluation as simple associative learningBackward blocking, unovershadowing and backward conditioned inhibition are examples of "retrospective revaluation" phenomena, that have been suggested to involve more than simple associative learning. Models of these phenomena have thus employed additional concepts, e.g. appealing to attentional effects or more elaborate learning mechanisms. I show that a suitable representation of stimuli, paired with a careful analysis of the discriminations faced by animals, leads to an account of these and other phenomena in terms of a simple "elemental" model of associative learning, with essentially the same learning mechanism as the Rescorla and Wagner (1972) model. I conclude with a discussion of some implications for theories of learning.
Stefano Ghirlanda2006-12-12Z2011-03-11T08:56:44Zhttp://cogprints.org/id/eprint/5299This item is in the repository with the URL: http://cogprints.org/id/eprint/52992006-12-12ZThe evolution of brain lateralization: A game theoretical analysis of population structure
In recent years, it has become apparent that behavioural and brain lateralization is the rule rather than the exception among vertebrates. The study of lateralization has been so far the province of neurology and neuropsychology. We show how such research can be integrated with evolutionary biology to more fully understand lateralization. In particular, we address
the fact that, within a species, left- and right-type individuals are often in a definite proportion different from 1/2 (e.g., hand use in humans). We argue that traditional explanations of brain lateralization (that it may avoid costly duplication of neural circuitry and reduce interference between functions) cannot account for this fact, because increased individual efficiency is unre-
lated to the frequency of left- and right-type individuals in a population. A further puzzle is that, if a majority of individuals are of the same type, individual behaviour becomes more predictable to other organisms. Here we
show that alignment of the direction of behavioural asymmetries in a population can arise as an evolutionarily stable strategy (ESS), when individually asymmetrical organisms must coordinate their behaviour with that of other
asymmetrical organisms. Thus, brain and behavioural lateralization, as we know it in humans and other vertebrates, may have evolved under basically
"social" selection pressures.
Stefano GhirlandaGiorgio Vallortigara2006-12-08Z2011-03-11T08:56:43Zhttp://cogprints.org/id/eprint/5279This item is in the repository with the URL: http://cogprints.org/id/eprint/52792006-12-08ZA century of generalizationWe review empirical data from both ethology and psychology about generalization, that is how animals respond to sets of stimuli including familiar as well as novel stimuli. Our main conclusion is that many characteristics of generalization are universal behavioural phenomena, suggesting that they originate from general properties of nervous mechanisms and/or that evolutionary strategies to cope with novelty and variability in stimulation are limited. We also reach the following conclusions. First, patterns of generalization are largely independent
of systematic group (evidence is available for insects, fish, amphibians, reptiles, birds and mammals, including humans), behavioural context (feeding, drinking, orientation, etc.), modality (light, sound, etc.) and of whether reaction to stimuli is learned or genetically inherited. Second, two major shapes of the generalization gradient can be identified, corresponding to two types of stimulus dimensions. When changes in stimulation involve a rearrangement of a constant amount of stimulation on the sense organs, the generalization gradient peaks close to familiar stimuli, and peak responding is not much higher than responding to familiar stimuli. When the dimension involves increase or decrease of the intensity of stimulation, the gradient is often monotonic, and responding
to some novel stimuli is considerably stronger than responding to familiar stimuli, compared to non-intensity dimensions. Third, rearrangement gradients are better described by Gaussian curves, rather than exponentials
as often suggested. Fourth, when several or many familiar stimuli are close to each other interferences occur, giving rise to predictable response biases such as peak shift or supernormality (interference between positive
and negative stimuli), and stretched bell shaped curves (several positive stimuli). Lastly, no principle differences between biases referred to as peak shift and biases referred to as supernormal stimulation are found. The paper ends with a discussion of theoretical issues.Stefano GhirlandaMagnus Enquist2006-12-08Z2011-03-11T08:56:43Zhttp://cogprints.org/id/eprint/5280This item is in the repository with the URL: http://cogprints.org/id/eprint/52802006-12-08ZThe evolution of signal form: Effects of learned versus inherited recognitionOrganisms can learn by individual experience to recognize relevant stimuli
in the environment or they can genetically inherit this ability from their
parents. Here, we ask how these two modes of acquisition affect signal evolution, focusing in particular on the exaggeration and cost of signals. We argue first, that faster learning by individual receivers cannot be a driving force for the evolution of exaggerated and costly signals unless signal senders are related or the same receiver and sender meet repeatedly. We argue instead that biases in receivers’ recognition mechanisms can promote the evolution of costly exaggeration in signals. We provide support for this hypothesis by simulating coevolution between senders and receivers, using artificial neural networks as a model of receivers’ recognition mechanisms. We analyse the joint effects of receiver biases, signal cost and mode of acquisition, investigating the circumstances under which learned recognition gives rise to more exaggerated signals than inherited recognition. We conclude the paper by discussing the relevance of our results to a number of biological scenarios.Masashi KamoStefano GhirlandaMagnus Enquist2007-12-19T03:04:07Z2011-03-11T08:57:02Zhttp://cogprints.org/id/eprint/5878This item is in the repository with the URL: http://cogprints.org/id/eprint/58782007-12-19T03:04:07ZHabituation of Predator Inspection and Boldness in the Guppy (Poecilia reticulata)This study examined habituation of the predator inspection behavior in the guppy (Poecilia reticulata) and its relationship with boldness (open field locomotion). Two different strategies were discovered: (1) initial inspection of a predator-like fish, correlated with boldness; (2) subsequent surveillance, governed by a random underlying process and unrelated with boldness. The surveillance inspection is probably linked with anti-predator vigilance. Possible implications to between-population variation in inspection behavior are discussed.Dr. Sergey Budaev2003-05-25Z2011-03-11T08:55:17Zhttp://cogprints.org/id/eprint/2971This item is in the repository with the URL: http://cogprints.org/id/eprint/29712003-05-25ZAnimal Consciousness as a Test Case of Cognitive ScienceIn our dealings with animals at least most of us see them as conscious beings. On the other hand the employment of human categories to animals seems to be problematic. Reflecting on the details of human beliefs, for example, casts serious doubt on whether the cat is able to believe anything at all. These theses try to reflect on methodological issues when investigating animal minds. Developing a theory of animal mentality seems to be a test case of the interdisciplinary research programme in cognitive science. From the philosopher`s perspective the most pressing problem is how to talk about animal minds. Can we just employ the vocabulary of human psychology? If not, exploring animal minds contains the non-trivial task of introducing a terminology that allows to see the distinctness of animal minds and to see its connection to the human case.
The treatment of some topic in cognitive science has to reach a reflective equilibrium between our intuitions, a phenomenological approach, philosophical conceptual analysis, various empirical approaches and model building. Reflective equilibrium means in this context that we have to reach a coherent model which incorporates as much of our intuitions concerning animal consciousness and integrates at the same time the findings of the different co-operating sciences. There can be various trade-offs in case of conflict between, say, philosophical definitions of mental terms as to be applied to animals, neurophysiology, our reflected intuitions and ethological model building based on a computational theory of animal minds.
The paper gives an example of reflective equilibrium in discussing the case for awareness in vertebrates. It considers the role of evolutionary reasoning. The main focus lays on two examples of comparing our human notions (chosen here are “having concepts” and “belief”) with corresponding abilities in animals, and how an appropriate conceptual apparatus dealing with the abilities of animals could be introduced.
Manuel Bremer2006-12-03Z2011-03-11T08:56:43Zhttp://cogprints.org/id/eprint/5272This item is in the repository with the URL: http://cogprints.org/id/eprint/52722006-12-03ZChickens prefer beautiful humansWe trained chickens to react to an average human female face but not to an average male face (or vice-versa). In a subsequent test, the animals showed preferences for faces consistent with human sexual preferences (obtained from university students). This suggests that human preferences arise from general properties of nervous systems, rather than from face-specific adaptations. We discuss this result in the light of current debate on the meaning of sexual signals, and suggest further tests of existing hypotheses about the origin of sexual preferences.
Stefano GhirlandaLiselotte JanssonMagnus Enquist2007-04-04Z2011-03-11T08:56:49Zhttp://cogprints.org/id/eprint/5477This item is in the repository with the URL: http://cogprints.org/id/eprint/54772007-04-04ZIndividuality in Fish Behavior: Ecology and Comparative PsychologyThis work is a brief review of a series of studies of the phenotypic organization and ecological significance of individual differences in fish behavior. The following species were studied: guppy Poecilia retuculata, lion-headed cichlid Steatocranus cassuarius, and the convict cichlid Archocentrus nigrofasciatum. We developed methods for the analysis of individual differences in fish behavior and studied their structure, development, and ecological and evolutionary significance.Dr. Sergey BudaevDr. Dmitry Zworykin2006-12-03Z2011-03-11T08:56:43Zhttp://cogprints.org/id/eprint/5273This item is in the repository with the URL: http://cogprints.org/id/eprint/52732006-12-03ZIntensity generalisation: physiology and modelling of a neglected topicI briefly review empirical data about the generalisation of acquired behaviour to novel stimuli, showing that variations in stimulus intensity affect behaviour differently from variations in characteristics such as, for instance, visual shape or sound frequency. I argue that such differences can be seen already in how the sense organs react to changes in intensity compared to changes in other stimulus characteristics. I then evaluate a number
of models of generalisation with respect to their ability to reproduce intensity generalisation. I reach three main conclusions. First, realistic stimulus representations, based on knowledge of the sense organs, are necessary to
account for intensity effects. Models employing stimulus representations too remote from the sense organs are unable to reproduce the data. Second, the intuitive notion that generalisation is based on similarities between stimuli, possibly modelled as distances in an appropriate representation space, is difficult to reconcile with data about intensity generalisation. Third, several simple models, in conjunction with realistic stimulus representations, can account for a wide array of generalisation phenomena along both intensity and non-intensity stimulus dimensions. The paper also introduces concepts which may be generally useful to evaluate and compare different models of behaviour.
Stefano Ghirlanda2006-12-08Z2011-03-11T08:56:43Zhttp://cogprints.org/id/eprint/5277This item is in the repository with the URL: http://cogprints.org/id/eprint/52772006-12-08ZSpectacular pehnomena and limits to rationality in genetic and cultural evolutionIn studies of both animal and human behaviour, game theory is used as a tool for understanding strategies that appear in interactions between individuals. Game theory focuses on adaptive behaviour, which can be attained only at evolutionary equilibrium. Here we suggest that behaviour appearing during interactions is often outside the scope of such analysis. In many types of interaction, conflicts of interest exist between players, fueling the evolution of manipulative strategies. Such strategies evolve out of equilibrium, commonly appearing as spectacular morphology or behaviour with obscure meaning, to which other players may react in non-adaptive, irrational way approach, and outline the conditions in which evolutionary equilibria cannot be maintained. Evidence from studies of biological interactions seems to support the view that behaviour is often not at equilibrium. This also appears to be the case for many human cultural traits, which have spread rapidly despite the fact that they have a negative influence on reproduction.Magnus EnquistAnthony ArakStefano GhirlandaCarl-Adam Wachtmeister2002-04-05Z2011-03-11T08:54:54Zhttp://cogprints.org/id/eprint/2163This item is in the repository with the URL: http://cogprints.org/id/eprint/21632002-04-05ZHomosexual Orientation in Males: Evolutionary and Ethological AspectsEvolutionary theory proposes that adaptive traits are reproduced more successfully than maladaptive traits. Accordingly, natural selection should favour heterosexuality as it facilitates reproduction and the propagation of genes. However, the question becomes, what has maintained homosexuality in a small but consistent percentage of the human population? Research into the evolutionary and hormonal factors associated with a homosexual orientation have yielded provocative but inconsistent results. It also suggests that human sexual orientation, and in particular homosexual orientation, is too complex to be described by one simple model or a single research discipline. The current paper treads a new path and emphasises an integrative approach for the understanding of homosexuality. The authors examine the combined effects of evolutionary factors and neurohormonal processes on the development of a homosexual orientation. It is suggested that research into the topic could benefit from an examination of and change in some of the assumptions upon which much past research has been based.Frank MuscarellaBernhard FinkKarl GrammerMichael Kirk-Smith2002-05-29Z2011-03-11T08:54:55Zhttp://cogprints.org/id/eprint/2228This item is in the repository with the URL: http://cogprints.org/id/eprint/22282002-05-29ZHomosexual Orientation in Males: Evolutionary and Ethological AspectsEvolutionary theory proposes that adaptive traits are reproduced more successfully than maladaptive traits. Accordingly, natural selection should favour heterosexuality as it facilitates reproduction and the propagation of genes. However, the question becomes, what has maintained homosexuality in a small but consistent percentage of the human population? Research into the evolutionary and hormonal factors associated with a homosexual orientation have yielded provocative but inconsistent results. It also suggests that human sexual orientation, and in particular homosexual orientation, is too complex to be described by one simple model or a single research discipline. The current paper treads a new path and emphasises an integrative approach for the understanding of homosexuality. The authors examine the combined effects of evolutionary factors and neurohormonal processes on the development of a homosexual orientation. It is suggested that research into the topic could benefit from an examination of and change in some of the assumptions upon which much past research has been based.Frank MuscarellaBernhard FinkKarl GrammerMichael Kirk-Smith2001-11-30Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1933This item is in the repository with the URL: http://cogprints.org/id/eprint/19332001-11-30ZInversion of initial dominance relationships following the interchange of roles of resident and intruder within pairs of male swordtail fish (Xiphophorus helleri)This experiment consisted of 75 different pairs composed of two male adults Xiphophorus helleri meeting each other twice. On the first occasion, one of the fish was familiarized with the meeting place for 3h (resident) while its opponent was familiarized with another aquarium (intruder). Upon dominance of one individual over the other, the pair members were separated and returned to their respective home groups for 168 hours (7 days). After this period of separation, the same pair members were reunited and met while roles had been reversed: the initial resident became the intruder, and the initial intruder was given prior-residency. Individuals in the initial resident role defeated the initial intruder in a significant majority of cases (76%). On their second meeting, the newly established dominance relationship was noted in favour of the new resident in a significant majority of cases (82%), and in a reversed direction as compared to the initially established dominance order. This shows that prior-residence is a powerful determinant of dyadic dominance outcome in Xiphophorus males when fish show minimal size differences. Claude GouletJacques Beaugrand2001-11-30Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1935This item is in the repository with the URL: http://cogprints.org/id/eprint/19352001-11-30ZRelation between dominance rank, prior agonistic intensity and subsequent aggressive levels in winners and losers of dyads of male Green swordtail fish (Xiphophorus helleri)Aggressive scores obtained in a mirror test 1h before an encounter were found to be a good predictor of victory in male Xiphophorus dyads showing less than 5% size differences. Out of 36 dyad members showing higher aggressive scores at pre-test, 28 obtained victory in the subsequent encounter. It was found that future winners were more aggressive than future losers to their own image in mirror tests before their encounter. Initial individual aggressive levels in mirror tests were also found to be a function of the rank the individuals occupied in their home hierarchies. The higher the rank, the higher was the individual aggressive level as measured by mirror pre-tests, as well as by post-tests. This relationship applied to future winners, as well as to future losers. The level of aggression reached during agonistic encounter was not a function of the social ranks the opponents occupied in their home hierarchies. Males in dyads composed of two omegas fought as fiercely as males in dyads of two alphas or two betas. No significant relationship was noted between the initial individual aggressive scores at mirror pre-test and the levels of aggression reached during encounters. We found in winners the existence of a significant correlation between the aggressive level they reached during agonistic encounter and a subsequent increase in aggressive levels at mirror tests 1h and 24h after victory. The more intense the agonistic encounter, the more important the subsequent increase in aggressive level in winners; an increase which was still detectable 24h after victory. However, prior alpha winners were apparently not as sensitive as prior betas and prior omegas to the aggressive level reached during the encounter since their mirror scores obtained after victory did not change when compared to their baseline at pre-test. After defeat, losers did not show any significant change in aggressive scores in mirror tests. Moreover, it was found that encounters in which a 1h resident met an intruder were in general less aggressive than encounters between two intruders. Experiential effects are discussed as instances of learning and generalisation.
Claude GouletJacques P. Beaugrand2002-04-05Z2011-03-11T08:54:55Zhttp://cogprints.org/id/eprint/2164This item is in the repository with the URL: http://cogprints.org/id/eprint/21642002-04-05ZHuman Pheromones: Integrating Neuroendocrinology and EthologyThe effect of sensory input on hormones is essential to any explanation of mammalian behavior, including aspects of physical attraction. The chemical signals we send have direct and developmental effects on hormone levels in other people. Since we don't know either if, or how, visual cues might have direct and developmental effects on hormone levels in other people, the biological basis for the development of visually perceived human physical attraction is currently somewhat questionable. In contrast, the biological basis for the development of physical attraction based on chemical signals is well detailed.James V. KohlMichaela AtzmuellerBernhard FinkKarl Grammer2007-04-04Z2011-03-11T08:56:49Zhttp://cogprints.org/id/eprint/5479This item is in the repository with the URL: http://cogprints.org/id/eprint/54792007-04-04ZIndidivual differences in the behaviour of fishesThis is the official printed Russian summary of PhD Thesis, describing a series of studies of the phenotypic organization and ecological significance of individual differences in fish behavior. The following species were studied: guppy Poecilia retuculata, lion-headed cichlid Steatocranus cassuarius, convict cichlid Archocentrus nigrofasciatum, wrasses Symphodus ocellatus, S. tinca, and two species of sturgeons Acipenser stellatus and A. gueldenstaedti. In this Thesis, I developed methods for the analysis of individual differences in fish behavior and studied their structure, development, and ecological and evolutionary significance.Dr. Sergey Budaev2001-11-30Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1936This item is in the repository with the URL: http://cogprints.org/id/eprint/19362001-11-30ZDistinguishing kinds of prior dominance and subordination experiences in male Green swordtail fish (Xiphophorus helleri).In experiments, there are usually two general ways of obtaining dominants and subordinates to test for the effect of recent experience upon ulterior behaviour and dominance. One is to impose such an experience on the contestants by a priori deciding which individual of the pair will become the dominant and which will become the subordinate through the use of rigged contests. The second technique is to let contestants self-select the winner and loser by waiting for the spontaneous outcome of dyadic encounters between two usually well matched opponents. These two techniques of obtaining dominants and subordinates probably represent extreme cases on a single continuum of investment made by animals to settle dominance. To test this, we compared dominants and subordinates obtained from these two techniques in Xiphophorus fish males. It was found that pairs obtained through rigged contests (R) were much more aggressive in subsequent encounters than pairs in which the dominant and subordinate could self-select (S). They recuperated more rapidly from handling, initiated contact earlier, took more time to assess each other, and fought for a longer period of time. Prior-winners and prior-losers of the R condition more frequently relied on aggressive behaviour during contest than that of the S condition. As a consequence, prior-winners and prior-losers of the R condition won equally the subsequent contest. On the contrary, prior-winners of the S condition defeated their prior-loser opponent in a majority of cases. These results can be tentatively explained by the following principle: winning or losing against a well matched opponent would leave more experience than winning over a much weaker opponent, or losing to a much stronger one. This reinforces the hypothesis that prior-experiences are not qualitative states but come in various degrees.
Jacques P. BeaugrandClaude Goulet1999-10-11Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/184This item is in the repository with the URL: http://cogprints.org/id/eprint/1841999-10-11ZThe Geometry of Stimulus ControlMany studies, both in ethology and comparative psychology, have shown that animals react to modifications of familiar stimuli. This phenomenon is often referred to as generalisation. Most modifications lead to a decrease in responding, but to certain new stimuli an increase in responding is observed. This holds for both innate and learned behaviour. Here we propose a heuristic approach to stimulus control, or stimulus selection, with the aim of explaining these phenomena. The model has two key elements. First, we choose the receptor level as the fundamental stimulus space. Each stimulus is represented as the pattern of activation it induces in sense organs. Second, in this space we introduce a simple measure of `similarity' between stimuli by calculating how activation patterns overlap. The main advantage we recognise in this approach is that the generalisation of acquired responses emerges from a few simple principles which are grounded in the recognition of how animals actually perceive stimuli. Many traditional problems that face theories of stimulus control (e.g. the Spence-Hull theory of gradient interaction or ethological theories of stimulus summation) do not arise in the present framework. These problems include the amount of generalisation along different dimensions, peak-shift phenomena (with respect to both positive and negative shifts), intensity generalisation, and generalisation after conditioning on two positive stimuliStefano GhirlandaMagnus Enquist1999-07-16Z2011-03-11T08:53:43Zhttp://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. Hammel1998-08-27Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/172This item is in the repository with the URL: http://cogprints.org/id/eprint/1721998-08-27ZThe Secrets of FacesThis is a comment on an article by Perrett et al., on the same issue of Nature, investigating face perception. With computer graphics, Perrett and colleagues have produced exaggerated male and female faces, and asked people to rate them with respect to femininity or masculinity, and personality traits such as intelligence, emotionality and so on. The key question is: what informations do faces (and sexual signals in general) convey? One view, supported by Perrett and colleagues, is that all aspects of sexual signals convey important information about partner quality. We suggest instead that the interaction between the signal and the receiver's nervous system can result in the evolution of sexual traits not linked to partner quality.Magnus EnquistStefano Ghirlanda2006-12-03Z2011-03-11T08:56:43Zhttp://cogprints.org/id/eprint/5271This item is in the repository with the URL: http://cogprints.org/id/eprint/52712006-12-03ZArtificial neural networks as models of stimulus controlWe evaluate the ability of artificial neural network models (multi-layer perceptrons) to predict stimulus-response relationships. A variety of empirical results are considered, such as generalization, peak-shift (supernormality) and stimulus intensity effects. The networks were trained on the same tasks as the animals in the considered experiments. The subsequent generalization tests on the networks showed that the model replicates correctly the empirical results. It is concluded that these models are valuable tools in the study of animal behaviour.
Stefano GhirlandaMagnus Enquist2006-12-08Z2011-03-11T08:56:43Zhttp://cogprints.org/id/eprint/5278This item is in the repository with the URL: http://cogprints.org/id/eprint/52782006-12-08ZDiscrete conventional signalling of a continuous variableIn aggressive interactions, animals often use a discrete set of signals,
while the properties being signalled are likely to be continuous, for example
fighting ability or value of victory. Here we investigate a particular model
of fighting which allows for conventional signalling of subjective resource
value to occur. The result shows that neither perfect nor no signalling are
evolutionarily stable strategies (ESSs) in the model. Instead, we find ESSs in
which partial information is communicated, with discrete displays signalling
a range of values rather than a precise one. The result also indicates that
communication should be more precise in conflicts over small resources.
Signalling strategies can exist in fighting because of the common interest
in avoiding injuries, but communication is likely to be limited because of
the fundamental conflict over the resource. Our results reflect a compromise
between these two factors. Data allowing for a thorough test of the model are lacking; however, existing data seem consistent with the obtained theoretical results.Magnus EnquistStefano GhirlandaPete L. Hurd1998-06-15Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/170This item is in the repository with the URL: http://cogprints.org/id/eprint/1701998-06-15ZEvolving cooperation in the non-iterated prisoner's dilemma: The importance of spatial organizationMost work on evolving cooperation in the Prisoner's Dilemma treats the non-iterated game as an undesirable simple case that should be risen above. It has been taken as a given that populations evolving to play the non-iterated game will always converge on defection. This paper questions this assumption, and demonstrates that organizing a population spatially dramatically changes the nature of the game and allows cooperation to emerge.M. Oliphant2002-11-19Z2011-03-11T08:55:06Zhttp://cogprints.org/id/eprint/2614This item is in the repository with the URL: http://cogprints.org/id/eprint/26142002-11-19ZSimpler for evolution: Secondary representation in apes, children, and ancestorsGreat apes show behavioural evidence for secondary representation similar to that of children of about two years of age. However, there is no convincing evidence for metarepresentation in apes. A good evolutionary interpretation should be parsimonious and must bring developmental and comparative data in accord. I propose a model based on the work of Perner (1991) and close by pointing out a logical flaw in Heyes’ second proposed experiment.
Thomas Suddendorf1998-06-18Z2011-03-11T08:53:49Zhttp://cogprints.org/id/eprint/328This item is in the repository with the URL: http://cogprints.org/id/eprint/3281998-06-18ZIndividualism and Evolutionary Psychology (or: In Defense of 'Narrow' Functions)Millikan and Wilson argue, for different reasons, that the essential reference to the environment in adaptationist explanations of behavior makes (psychological) individualism inconsistent with evolutionary psychology. I show that their arguments are based on misinterpretations of the role of reference to the environment in such explanations. By exploring these misinterpretations, I develop an account of explanation in evolutionary psychology that is fully consistent with individualism. This does not, however, constitute a full-fledged defense of individualism, since evolutionary psychology is only one explanatory paradigm among many in psychology.David J. Buller1997-09-30Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/160This item is in the repository with the URL: http://cogprints.org/id/eprint/1601997-09-30ZCognitive Ethology: Slayers, Skeptics, and ProponentsIn this paper we identify three major groups of people (among some of whose members there are blurred distinctions) with different views on cognitive ethology, namely, slayers, skeptics, and proponents. Our analyses are based on our reading of some published reviews of Donald Griffin's works in cognitive ethology and other clearly stated opinions concerning animal cognition, in the sense of attribution of mental states and properties such as beliefs, awareness, and consciousness. Slayers Slayers deny any possibility of success in cognitive ethology. In our analyses of their published statements, we have found that they sometimes conflate the difficulty of doing rigorous cognitive ethological investigations with the impossibility of doing so. Slayers also often ignore specific details of work by cognitive ethologists and frequently mount philosophically motivated objections to the possibility of learning anything about animal cognition. Slayers do not believe that cognitive ethological approaches can lead, and have lead, to new and testable hypotheses. They often pick out the most difficult and least accessible phenomena to study (e.g. consciousness) and then conclude that because we can gain little detailed knowledge about this subject, we cannot do better in other areas. Slayers also appeal to parsimony in explanations of animal behavior, but they dismiss the possibility that cognitive explanations can be more parsimonious than noncognitive alternatives, and they deny the utility of cognitive hypotheses for directing empirical research. Skeptics Skeptics are often difficult to categorize. They are a bit more open-minded than slayers, and there seems to be greater variation among skeptical views of cognitive ethology than among slayers' opinions. However, some skeptics recognize some past and present successes in cognitive ethology, and remain cautiously optimistic about future successes; in these instances they resemble moderate proponents. Many skeptics appeal to the future of neuroscience, and claim that when we know all there is to know about nervous systems, cognitive ethology will be superfluous (Bekoff, 1993a; it should be noted that Griffin, 1992 also makes strong appeals to neuroscience, but he does not believe that increased knowledge in neurobiology will cause cognitive ethology to disappear). Like slayers, skeptics frequently conflate the difficulty of doing rigorous cognitive ethological investigations with the impossibility of doing so. Skeptics also find folk psychological, anthropomorphic, and cognitive explanations to be off-putting. Proponents Proponents recognize the utility of cognitive ethological investigations. They claim that there are already many successes and they see that cognitive ethological approaches have provided new and interesting data that also can inform and motivate further study. Proponents also accept the cautious use of folk psychological and cognitive explanations to build a systematic explanatory framework in conjunction with empirical studies, and do not find anecdotes or anthropomorphism to be thoroughly off-putting. Some proponents are as extreme in their advocacy of cognitive ethology as some slayers are in their opposition. But most proponents are willing to be critical of cognitive ethological research without dooming the field prematurely; if cognitive ethology is to die, it will be of natural causes and not as a result of hasty slayings. M BekoffC Allen2001-11-30Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1937This item is in the repository with the URL: http://cogprints.org/id/eprint/19372001-11-30ZCoherent use of information by hens assisting to the victory or defeat of their former dominant by a stranger: a case of transitive inference?We examine the role of observation during the formation of triads in females of the domestic fowl. During hierarchy formation, a hen observing agonistic interactions and conflict settlement between its former dominant and a stranger uses this information when in turn confronted by the latter. Under a first condition, bystanders witnessed their prior dominant being defeated by a stranger before being introduced to them. In a second condition, bystanders witnessed the victory of their prior dominant over a stranger. In a third condition, bystanders witnessed two strangers establishing a dominance relationship before being introduced to their prior dominant and to a stranger the former had just defeated. It was found that behavioural strategies of bystanders depended on the issue of the conflict they had just witnessed. Bystanders which had attended to the defeat of their prior dominant behaved as having no chance of defeating the stranger. They never initiated an attack against it, and upon being attacked, readily submitted in turn to the stranger. On the contrary, bystanders which had witnessed the victory of their prior dominant over the stranger behaved as having some chances against the stranger. They initiated attacks in 50% of cases, and won 50% of conflicts against the stranger. When bystanders had not attended the meeting of their prior dominant, they first initiated contact with the strangers in only 27% of cases, which approximates the average of their chances for defeating the stranger. However, bystanders finally defeated the strangers in 40% of cases. These results suggest that bystanders which had witnessed the encounter of their prior dominant with the stranger had gained some information on the relationship established between them. When confronted in turn to the stranger, observers used this information coherently, perhaps through transitive inference, thus contributing to the existence of transitive relationships within the triads. It is proposed that observational or vicarious learning could account for «transitive inference» in this case: the observer would simply reproduce the behaviour the prior dominant had shown towards the stranger.
The paper in in FrenchJacques P. BeaugrandMichèle E. HoguePaul C. Lague1998-06-24Z2011-03-11T08:53:59Zhttp://cogprints.org/id/eprint/475This item is in the repository with the URL: http://cogprints.org/id/eprint/4751998-06-24ZThe conceptual nature of knowledge, situations, and activity.Situated action can be viewed as a psychological theory about the dynamic relation of conceiving and acting; and as a social theory about the nature of activity as a social choreography. Conventional views of interactivity reduce concepts to words, situations to data, and activities to descriptions of disembodied tasks. The difference between tasks and activities suggests new ways for using computers to facilitate work and learning.William J. Clancey1997-10-14Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/161This item is in the repository with the URL: http://cogprints.org/id/eprint/1611997-10-14ZDeep EthologyThis essay is basically autobiographical. I discuss some of my own research and views on animal cognition and animal welfare/rights.Marc Bekoff1998-05-25Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/168This item is in the repository with the URL: http://cogprints.org/id/eprint/1681998-05-25ZEpistemic Autonomy in Models of Living SystemsThis paper discusses epistemological consequences of embodied AI for Artificial Life models. The importance of robotic systems for ALife lies in the fact that they are not purely formal models and thus have to address issues of semantic adaptation and epistemic autonomy, which means the system's own ability to decide upon the validity of measurements. Epistemic autonomy in artificial systems is a difficult problem that poses foundational questions. The proposal is to concentrate on biological transformations of epistemological questions that have lead to the development of modern ethology. Such an approach has proven to be useful in the design of control systems for behavior-based robots. It leads to a better understanding of modern ontological conceptions as well as a reacknowledgement of finality in the description and design of autonomous systems.Erich Prem1997-09-26Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/156This item is in the repository with the URL: http://cogprints.org/id/eprint/1561997-09-26ZIntentional Communication and Social Play: How and Why Animals Negotiate and Agree to PlayIn these papers we mainly consider how analyses of social play in nonhuman animals (hereafter animals) can inform inquiries about the evolution of cognitive mechanisms. Social play is a good behavioral phenotype on which to concentrate for when animals play they typically perform behavior patterns that are used in other contexts (e.g. predation, aggression, or reproduction). Thus, individuals need to be able to tell one another that they do not want to eat, fight with, or mate with the other individual(s), but rather, they want to play with them. In most species (primarily mammals) in which play has been observed, specific actions have evolved that are used to initiate or to maintain play. Furthermore, sequences of play usually differ from nonplay sequences (within species) and self-handicapping has also been observed, in which, for example, dominant individuals allow themselves to be dominated _only_ in the context of play. In our consideration of how play is initiated and maintained, we discuss issues including the evolution of play, the ecology of play, the sorts of information that are shared during play, what cognitive psychologists who study humans can learn from cognitive ethologists who study other animals, and what play can tell us about the emergence of mind in animals. These essays draw on literature from ethology, psychology, and philosophy. Marc BekoffColin Allen1997-10-14Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/162This item is in the repository with the URL: http://cogprints.org/id/eprint/1621997-10-14ZPlaying with Play What Can We Learn About Cognition, Negotiation, and Evolution?In these papers we mainly consider how analyses of social play in nonhuman animals (hereafter animals) can inform inquiries about the evolution of cognitive mechanisms. Social play is a good behavioral phenotype on which to concentrate for when animals play they typically perform behavior patterns that are used in other contexts (e.g. predation, aggression, or reproduction). Thus, individuals need to be able to tell one another that they do not want to eat, fight with, or mate with the other individual(s), but rather, they want to play with them. In most species (primarily mammals) in which play has been observed, specific actions have evolved that are used to initiate or to maintain play. Furthermore, sequences of play usually differ from nonplay sequences (within species) and self-handicapping has also been observed, in which, for example, dominant individuals allow themselves to be dominated _only_ in the context of play. In our consideration of how play is initiated and maintained, w discuss issues including the evolution of play, the ecology of play, the sorts of information that are shared during play, what cognitive psychologists who study humans can learn from cognitive ethologists who study other animals, and what play can tell us about the emergence of mind in animals. These essays draw on literature from ethology, psychology, and philosophy.Marc Bekoff2001-12-07Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1965This item is in the repository with the URL: http://cogprints.org/id/eprint/19652001-12-07ZRelative importance of initial individual differences, victory and defeat experiences, and assessment accuracy during hierarchy formation: A simulation studyThis simulation study explores some conditions leading to transitivity within dominance orders. Combinations of three parameters were varied to study their consequences upon hierarchy formation and upon the degree of linearity of resultant structures. The factors studied were (i) the importance of initial Resource Holding Potentials (RHPs) , (ii) changes brought in RHPs by successive victories and defeats, and (iii) accuracy of RHP assessment made by opponents. Results show that initial differences in RHP always lead to perfectly transitive chains whose rank order reflects the importance of initial differences. Even when simulated animals make important errors while assessing each other during round robin tournaments, emerging dominance structures are perfectly linear and ranks obtained in the structure are highly correlated with initial values in RHPs. Moreover, accumulated experiences of victory and/or defeat alone always lead to perfectly linear hierarchies. Their combination with initial individual differences in RHP led to the same conclusion. Even when assessment was far from being perfect, not only perfect chains were formed but initial values in RHPs significantly influenced rank order when the contribution of victory and defeat to RHP was relatively unimportant. The higher the importance of victory and defeat to RHP as compared to that of initial RHP values, the lower was the correlation between initial RHP values and the ranks order reached by individuals in the resultant hierarchies. In general also, the lower the variation within initial RHPs, the lower was the correlation between initial RHPs and ranks in the hierarchy. At a given level of initial RHP dispersion, increasing the contribution of victory and defeat to RHP diminished the correlation between initial RHP values and obtained ranks. In addition, inaccurate assessment reduced the overall correlation, especially when dispersion of initial RHP values was low and the contribution of victory and defeat was high. These results shed some light on the controversy about the respective roles of initial individual attributes and that of patterns of resolution in the formation of animal hierarchies. We present the emergence of social order within closed systems as those simulated here as a case of self-organization.
Jacques P. Beaugrand2001-12-01Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1944This item is in the repository with the URL: http://cogprints.org/id/eprint/19442001-12-01ZResolution of agonistic conflicts in dyads of acquainted green swordtails (Xiphophorus helleri, Pisces, Poeciliidae): A game with perfect informationConflict resolution of familiar opponents was compared to that of unfamiliar ones in Xiphophorus helleri males. Under the Familiar condition, the two males which met had settled a contest against each other in a previously staged encounter in another aquarium. Thus one opponent was the previously dominant pair member, the other its previously subordinate. Under the Unfamiliar condition, two males met which were not acquainted with each other but had independently undergone previous experience of victory or defeat. We tested the hypothesis that familiar pairs would conform to some behaviourial predictions of an «asymmetrical game with perfect information». As for unfamiliar pairs, being uninformed of asymmetries at a contest onset, they would have to acquire information on these during the course of interaction («asymmetrical game with assessment») or alternatively would have to persist for a certain time or cost («war of attrition»). All expectations derived from an «asymmetrical game with perfect information» applied to familiar pairs but not to unfamiliar ones. In familiar pairs, all prior roles were reinstated without any escalation. Though prior winners predominantly defeated prior losers under both conditions of cognizance, this difference was more extreme in familiar dyads than in unfamiliar ones. This suggests that the respective roles were less clearly identified in the latter. The costs of conflicts both in terms of aggressive behaviours used and in time were also higher in unfamiliar pairs than in familiar ones. Unacquainted individuals required a longer period to assess each other. In addition, they had to rely on more pugnacious behaviour to settle disputes in comparison to acquainted pairs. As expected also, familiar pairs being already cognizant of initial respective roles were more characterized in terms of the behavioural patterns typical of each of these roles. Differences between ultimate winners and losers were more clear in acquainted pairs, and appeared earlier during conflict. It was also possible earlier during contest to discriminate and to predict ultimate winners from losers of acquainted pairs using behavioural interactions. In most unacquainted pairs, ultimate winners could be forecasted using multivariate discriminant analyses, mainly by their offering «resistance» to future losers. A «war of attrition» did not fit to unacquainted pairs.Jacques P. Beaugrand2001-12-02Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1952This item is in the repository with the URL: http://cogprints.org/id/eprint/19522001-12-02ZThe role of hen's weight and recent experience on dyadic conflict outcomeThis study simultaneously varied experiences of recent victory or defeat, 2-hour familiarity with the meeting place, and hen weight in order to understand their combined effects on the establishment of dyadic dominance relationships between hens not previously acquainted with each other. Three kinds of encounters were arranged: (i) a previous winner unfamiliar with the meeting place met a previous loser familiar with the meeting place (n =28 dyads); (ii) a previous winner met a previous loser, both unfamiliar with the meeting place (n=27); (iii) a previous winner familiar with the meeting place encountered a previous loser unfamiliar with the meeting place (n=28). The weight asymmetry was combined with these three types of encounters by selecting hens showing various weight differences, in favour of the recent loser in 54 dyads and of the recent winner in 29 dyads. Results indicate that recent victory or defeat experience significantly affected the outcome. Even an important weight asymmetry, or familiarity with the meeting place were not sufficient for a hen recently defeated to overcome an opponent that was previously victorious. A 2-hour period of familiarization with the meeting place did not provide any significant advantage over unfamiliarity. Although a significant relationship was found to exist between comb and wattles areas and the initial and final statuses, examination of partial correlations indicates that the influence was from initial status to final status, rather than from comb and wattles to final status. These results suggest that more importance should be attributed to recent social experience in comparison to intrinsic factors in determining dyadic dominance in the hen.
François MartinJacques P. BeaugrandPaul C. Lague2001-12-01Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1938This item is in the repository with the URL: http://cogprints.org/id/eprint/19382001-12-01ZThe role of recent experience and weight on hen's agonistic behaviour during dyadic conflict resolution.Recent victory or defeat experiences and 2-hour familiarity with the meeting place were combined with size differences in order to better understand their effects on the behaviour leading to the establishment of dyadic dominance relationships between hens not previously acquainted with each other. Three kinds of encounters were videotaped: (i) a previous winner unfamiliar with the meeting place met a previous loser familiar for 2 hours with the meeting place (n = 12 dyads); (ii) as in (i) but both were unfamiliar with the meeting place (n=12); (iii) as in (i) but the previous winner was familiar with the meeting place while the previous loser was unfamiliar (n=13). The weight asymmetry was combined with these three types of encounters by selecting hens of various weight differences: in 29 dyads the recent loser was heavier than the recent winner and in 8 dyads it was the reverse. Recent experience had a major influence upon both agonistic behaviour and dominance outcome. Hens that were familiar with the meeting site initiated attacks more frequently than their unfamiliar opponent but did not win significantly more often. Recent experience and site familiarity could be used to identify 80% of future initiators. Once the first aggressive behaviour had been initiated, it led to victory of its initiator in 92% of cases. Weight was not found to influence agonistic behaviour nor dominance outcome. However, hens with superior comb and wattles areas won significantly more initial meetings than opponents with smaller ones. In the final encounters, victory also went more frequently to the bird showing larger comb and wattles, which happened also to be the previous dominant in a majority of cases. The use of higher-order partial correlations as an ex post facto control for comb and wattles indicates that they were not influential upon agonistic behaviour nor on dominance outcome, but were simply co-selected with the selection of victorious and defeated birds in the first phase of the experiment designed to let hens acquire recent victory/defeat experience.
François MartinJacques P. BeaugrandPaul C. Lague1998-06-09Z2011-03-11T08:53:57Zhttp://cogprints.org/id/eprint/448This item is in the repository with the URL: http://cogprints.org/id/eprint/4481998-06-09ZAction Selection in a hypothetical house robot: Using those RL numbersReinforcement Learning (RL) methods, in contrast to many forms of machine learning, build up value functions for actions. That is, an agent not only knows `what' it wants to do, it also knows `how much' it wants to do it. Traditionally, the latter are used to produce the former and are then ignored, since the agent is assumed to act alone. But the latter numbers contain useful information - they tell us how much the agent will suffer if its action is not executed (perhaps not much). They tell us which actions the agent can compromise on and which it cannot. It is clear that many interesting systems possess multiple parallel and conflicting goals, all demanding attention, and none of which can be fully satisfied expect at the expense of others. Animals are the prime example of such systems. In [Humphrys, 1995], I introduced the W-learning algorithms, showing one method of resolving competition among behaviors automatically by reference to their RL values. The scheme has the unusal feature that behaviors are at all times in selfish pursuit of their own goals and have no explicit concept of cooperation, despite residing in the same body. In this paper, I apply W-learning to the world of a hypothetical house robot, which doubles as family toy, movile security camera, mobile smoke alarm and occasional vacuum cleaner. I show how a W-learning community of behaviors inside the robot will support a robust behavior pattern, capabable of opportunistic behavior, avoiding dithering, and allowing for the concept of default behavior and expression of low-priority goals.Mark Humphrys1998-06-09Z2011-03-11T08:53:57Zhttp://cogprints.org/id/eprint/447This item is in the repository with the URL: http://cogprints.org/id/eprint/4471998-06-09ZAction Selection methods using Reinforcement LearningAction Selection schemes, when translated into precise algorithms, typically involve considerable design effort and tuning of parameters. Little work has been done on solving the problem using learning. This paper compares eight different methods of solving the action selection problem using Reinforcement Learning (learning from rewards). The methods range from centralised and cooperative to decentralised and selfish. They are tested in an artificial world and their performance, memory requirements and reactiveness are compared. Finally, the possibility of more exotic, ecosystem-like decentralised models are considered.Mark Humphrys1997-08-19Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/154This item is in the repository with the URL: http://cogprints.org/id/eprint/1541997-08-19ZCognitive Ethology, Vigilance, Information Gathering, and Representation: Who Might Know What and Why?Cognitive ethology, a relatively new interdisciplinary and integrative science, is under attack with respect to its scientific status. However, there also are strong supporters of research in this area. In this paper I consider (1) some of the topics in which cognitive ethologists are interested, (2) possible connections between cognitive analyses of social behavior and philosophical concepts including intentionality and representation, (3) recent work on vigilance or scanning behavior in highly social birds, Evening Grosbeaks (Coccothraustes vespertinus), that benefits from taking a cognitive perspective, and (4) what may be gained by taking a cognitive approach to the study of social behavior and what may be lost by not doing so. My study of vigilance indicates that the way in which individuals are positioned with respect to one another influences their behavior, and that when a flock contains four or more birds there are large changes in scanning and other patterns of behavior that may be related to how grosbeaks attempt to gather information about other flock members. When birds are arranged in a circular array so that they can see one another easily compared to when they are arranged in a line that makes visual monitoring of flock members more difficult, birds who have difficulty seeing one another are (i) more vigilant, (ii) change their head and body positions more often, (iii) react to changes in group size more slowly, (iv) show less coordination in head movements, and (v) show more variability in all measures. These differences in behavior argue against the pooling of data collected on individuals feeding in different geometric arrays. The variations in behavior also may say something about if and how individuals attempt visually to represent their group to themselves--how they form, store, and use records of the behavior of others to inform their own future behavior. Marc Bekoff2001-12-01Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1939This item is in the repository with the URL: http://cogprints.org/id/eprint/19392001-12-01ZCoherent use of information by hens observing their former dominant defeating or being defeated by a stranger.This study examines the role of observation during the formation of triads in female domestic hens. Results indicate that during hierarchy formation, a hen observing agonistic interactions and conflict settlement between its former dominant and a stranger uses this information when in turn confronted by the latter. Under a first condition (E, N=15 triads), bystanders witnessed their prior dominant being defeated by a stranger before being introduced to them. In a second condition (C1, N=16 triads), bystanders witnessed the victory of their prior dominant over a stranger. In a third condition (C2, N=15 triads), bystanders witnessed two strangers establishing a dominance relationship before being introduced to their prior dominant and to a stranger the former had just defeated. The behavioural strategies of bystanders depended on the issue of the conflict they had witnessed. Bystanders of the E condition behaved as having no chance of defeating the stranger. They never initiated an attack against it, and upon being attacked, readily submitted in turn to the stranger. On the contrary, bystanders of the C1 condition behaved as having some chances against the stranger. They initiated attacks in 50% of cases, and won 50% of conflicts against the stranger. Under condition C2, bystanders first initiated contact with the strangers in only 27% of cases, which approximates the average of their chances for defeating the stranger. However, bystanders finally defeated the strangers in 40% of cases. These results suggest that bystanders of conditions E and C1 gained some information on the relationship existing between their prior dominant and the stranger and that they used it coherently, perhaps through transitive inference, thus contributing to the existence of transitive relationships within the triads. Alternate explanations are examined.Michèle E. HogueJacques P. BeaugrandPaul C. Lague2001-12-01Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1953This item is in the repository with the URL: http://cogprints.org/id/eprint/19532001-12-01ZConflict outcome in male green swordtail fish dyads (Xiphophorus helleri): Interaction of body size, prior dominance/subordination experience and prior residencyThe relative contribution of asymmetries in prior experience, size, and prior residency to the determination of dyadic dominance between unacquainted individuals was examined using pairs of green swordtail fish, Xiphophorus helleri. Four types of encounters were staged between an intruder and a smaller resident: (1) both had experienced prior victory; (2) both had experienced prior defeat; (3) the intruder had experienced prior victory and the resident prior defeat; and (4) the intruder had experienced prior defeat and the resident prior victory. In a fifth condition in which two intruders met, one was a prior subordinate and the other a prior dominant smaller in size than its opponent. In all these encounters, the superiority in lateral surface of one fish varied between 0 to 30% over that of its opponent. Results showed that (1) when size differences between contestants were within the range of 0-10% and there was an asymmetry in prior social experience, conflicts were essentially resolved according to prior experience with prior winners systematically defeating prior losers; (2) prior residency of 3 hours was an advantage only when both opponents had experienced prior defeat before meeting and when size asymmetries were small (e.g. <20%). It was not an advantage between prior winners or between a prior winner and a prior loser; (3) when large size asymmetries existed (e.g. 20-30%), size uniquely determined dominance outcome and nullified other advantages or disadvantages due to prior social experience and prior residency; and (4) at intermediate levels of size asymmetries (e.g. 10-20%), size partially cancelled any advantage due to a prior victory, and gradually beacme the most important factor in accounting for victories.
Jacques P. BeaugrandDaniel PayetteClaude Goulet1998-06-15Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/169This item is in the repository with the URL: http://cogprints.org/id/eprint/1691998-06-15ZThe Dilemma of Saussurean CommunicationA Saussurean communication system exists when an entire communicating population uses a single "language" that maps states unambiguously onto symbols and then back into the original states. This paper describes a number of simulations performed with a genetic algorithm to investigate the conditions necessary for such communication systems to evolve. The first simulation shows that Saussurean communication evolves in the simple case where direct selective pressure is placed on individuals to be both good transmitters and good receivers. The second simulation demonstrates that, in the more realistic case where selective pressure is only placed on doing well as a receiver, Saussurean communication fails to evolve. Two methods, inspired by research on the Prisoner's Dilemma, are used to attempt to solve this problem. The third simulation shows that, even in the absence of selective pressure on transmission, Saussurean communication can evolve if individuals interact multiple times with the same communication partner and are given the ability to respond differentially based on past interaction. In the fourth simulation, spatially organized populations are used, and it is shown that this allows Saussurean communication to evolve through kin selection.Michael Oliphant2001-12-04Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1960This item is in the repository with the URL: http://cogprints.org/id/eprint/19602001-12-04ZThe role of individual differences and patterns of resolution in the formation of dominance orders in domestic hens triadsThis research compares the role of initial individual characteristics to that of patterns of resolution in which successive dominance relationships are established during the formation of triads in the domestic hen. Combining weight, prior victory or defeat in the site of encounter, and comb size, we created three levels of asymmetries on characteristics for triads of hens. The effects of these asymmetries were then examined on the resultant hierarchies and on the order of conflict resolution within triads under two different conditions of assembly. In one condition (simultaneous triad), the three hens were simultaneously introduced to each other and could thus freely choose their opponent. In the other condition (step-assembled triad), the hen predicted to occupy the highest rank was left on standby and introduced once the two other hens had settled dominance, thus disrupting the normal process of hierarchy formation by imposing the first sequence of dominance settlement. We found that the structure of triadic hierarchies can be predicted from individual characteristics existing prior to hierarchy formation. No differences in the resultant structures were found between conditions of introduction, though different paths of conflict resolution were followed indicating that individual differences had a more determining role on the resultant hierarchies than patterns of resolution. Beside showing that individual differences determine resultant triadic structures, the present results also show that the same end structures can be reached by following resolution paths that are not necessarily of the Double Dominance and Double Subordinance types as prescribed by Chase's model. It is also found that in the simultaneous condition hens select each other to form pairs. Therefore, individuals do not meet at random but choose each other as opponents. The two hens predicted from individual differences to occupy the highest ranks first settle dominance, followed by settlement between the winner of the previous encounter and the bystander.Sylvie CloutierJacques P. BeaugrandPaul C. Lague2001-12-01Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1943This item is in the repository with the URL: http://cogprints.org/id/eprint/19432001-12-01ZThe role of observation and of individual differences in in the determination of rank order in triads of male green swordtail fish (Xiphophorus helleri)Triads of Xiphophorus helleri males composed of a large prior winner (A), a small prior winner (a), and a small prior loser (w) were formed. In one condition, A was used as bystander while in another condition it was the small w. The bystander could see through a transparent partition and observe conflict settlement between the two other fish without interacting with them. As soon as a dominance relationship clearly emerged, the partition was raised and the fish on standby could establish dominance relationships with them. The most frequent triadic structures obtained were A >a>w and A>w>a indicating that individual characteristics played a determinant role in hierarchy formation. Patterns of assembly depended on individual differences of the fish. The fact that the same dominance structures were reached through various patterns of assembly suggests that individual differences are more determinant than paths of resolution in Xiphophorus.Jacques P. BeaugrandPierre-Alain Cotnoir2001-12-04Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1959This item is in the repository with the URL: http://cogprints.org/id/eprint/19592001-12-04ZSelecting dominants and subordinates at conflict outcome can confound the effects of prior dominance or subordination experienceIndividuals with a previous experience of dominance are likely to be dominants in further encounters. To test this effect, individuals with a previous experience of dominance are used for the experiments. One way to obtain such individuals is to let opponents «self-select»: encounters between pairs of more or less equivalent opponents are staged and one selects ex post facto the dominant and subordinate from the ensuing conflict. This paper formally shows that the selection of dominant and subordinate animals modifies the dominance probability functions of the two corresponding sub-samples of animals. As a result, the propensity of previous winners to win again and of previous losers to repeat their loss can be attributed to this artefact rather than to prior social experience. A simulation confirms the results of the theoretical analysis. This result has serious methodological implications. When one relies solely on selection to obtain winners and losers, equiprobability is no longer the appropriate null hypothesis against which prior social experience effects have to be tested. To clearly demonstrate the effect of dominance experience, one must show that prior winners defeat neutral opponents in at least of all cases; reciprocally, to show that prior subordinate experience plays a role, prior losers must win in less than of all fights against neutral opponents; finally, to conclude that a combined effect of the two kinds of prior experience is in operation, one must obtain that prior winners defeat prior losers in more than 83% of all planned conflicts. The present result does not imply that experience effects are not at work when the selection procedure is used, but that the procedure used to show their effects is inadequate because effects of experience on a subsequent encounter are confounded with those introduced by statistical selection
Jean BéginJacques P. BeaugrandRené Zayan1998-06-09Z2011-03-11T08:53:58Zhttp://cogprints.org/id/eprint/452This item is in the repository with the URL: http://cogprints.org/id/eprint/4521998-06-09ZW-learning: Competition among selfish Q-learnersW-learning is a self-organising action-selection scheme for systems with multiple parallel goals, such as autonomous mobile robots. It uses ideas drawn from the subsumption architecture for mobile robots (Brooks), implementing them with the Q-learning algorithm from reinforcement learning (Watkins). Brooks explores the idea of multiple sensing-and-acting agents within a single robot, more than one of which is capable of controlling the robot on its own if allowed. I introduce a model where the agents are not only autonomous, but are in fact engaged in direct competition with each other for control of the robot. Interesting robots are ones where no agent achieves total victory, but rather the state-space is fragmented among different agents. Having the agents operate by Q-learning proves to be a way to implement this, leading to a local, incremental algorithm (W-learning) to resolve competition. I present a sketch proof that this algorithm converges when the world is a discrete, finite Markov decision process. For each state, competition is resolved with the most likely winner of the state being the agent that is most likely to suffer the most if it does not win. In this way, W-learning can be viewed as `fair' resolution of competition. In the empirical section, I show how W-learning may be used to define spaces of agent-collections whose action selection is learnt rather than hand-designed. This is the kind of solution-space that may be searched with a genetic algorithm.Mark Humphrys1997-09-30Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/157This item is in the repository with the URL: http://cogprints.org/id/eprint/1571997-09-30ZCognitive Ethology and the Explanation of Nonhuman Animal BehaviorIn each essay I discuss some aspects of the field of cognitive ethology and show how interdisciplinary research can inform evolutionary, comparative, and ecological studies of animal minds. I stress the importance of studying animals other than primates.Marc Bekoff1997-09-30Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/159This item is in the repository with the URL: http://cogprints.org/id/eprint/1591997-09-30ZCognitive Ethology: The Comparative Study of Animal MindsIn each essay I discuss some aspects of the field of cognitive ethology and show how interdisciplinary research can inform evolutionary, comparative, and ecological studies of animal minds. I stress the importance of studying animals other than primates. Marc Bekoff2001-12-01Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1940This item is in the repository with the URL: http://cogprints.org/id/eprint/19402001-12-01ZThe effect of prior victory or defeat in the same site as that of subsequent encounter on the determination of dyadic dominance in the domestic henWe examined the effect of prior victory or defeat in the same site as that of a subsequent encounter on the outcome of dyadic encounter of domestic hens by placing them in two situations: In the first set of dyads, two unacquainted hens having experienced prior victory were introduced in the site where one had experienced victory. In the second set, two unacquainted hens having experienced defeat were introduced in the site where one had recently lost. Results indicate that victories are equally shared between individuals with prior victory experiences, while familiarity with the meeting site did not give any advantage. However, hens having previously lost were disadvantaged when the encounter occurred in the same site as that of their prior defeat. This demonstrates that previous social experience in a site is more important on the outcome of subsequent encounters for losers than winners. Losers seem to associate the site with the stressful effect of losing or being more easily dominated.Sylvie CloutierJacques P. BeaugrandPaul C. Lague1997-09-30Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/158This item is in the repository with the URL: http://cogprints.org/id/eprint/1581997-09-30ZPlay Signals as Punctuation: The Structure of Social Play in CanidsActions called play signals have evolved in many species in which social play has been observed. Despite there being only few empirical demonstrations, it generally is accepted that play signals are important in the initiation ("I want to play") and maintenance ("I still want to play") of ongoing social play. In this study I consider whether a specific and highly stereotyped signal, the bow, is used to maintain social play in adult and infant domestic dogs, infant wolves, and infant coyotes. To answer this question the temporal placement of bows relative to actions that are also used in other contexts (dominance or predatory encounters) such as biting accompanied by rapid side-to-side shaking of the head was analyzed to determine if bows performed during ongoing social play are used to communicate the message "I want to play despite what I am going to do or just did -- I still want to play." The nonrandom occurrence of bows supports the hypothesis that bows are used to maintain social play in these canids when actions borrowed from other contexts, especially bites accompanied by rapid side-to-side shaking of the head, are likely to be misinterpreted. Marc Bekoff1998-06-09Z2011-03-11T08:53:57Zhttp://cogprints.org/id/eprint/450This item is in the repository with the URL: http://cogprints.org/id/eprint/4501998-06-09ZTowards self-organising Action SelectionSystems with multiple parallel goals (e.g. autonomous mobile robots) have a problem analogous to that of action selection in ethology. Architectures such as the subsumption architecture (Brooks) involve multiple sensing-and-acting agents within a single robot on its own if allowed. Which to give control at a given moment is normally regarded as a (difficult) problem of design. In a quest for a scheme where the agents decide for themselves in a sensible manner, I introduce a model where the agents are not only autonomous but are in full competition with each other for control of the robot. Interesting robots are ones where no agent achieves total victory, but rather a serires of compromises are reached. Having the agents operate by the reinforcement learning algorithm Q-learning (Watkins) allows the introduction of an algorithm called `W-learning', by which the agents learn to focus their competitive efforts in a manner similar to agents with limited spending power in an economy. In this way, the population of agents organises its own action selection in a coherent way that supports parallelism and opportunism. In the empirical section, I show how the relative influence an agent has on its robot may be controlled by adjusting its rewards. The possibility of automated search of agent-combinations is considered.Mark Humphrys1997-08-20Z2011-03-11T08:53:42Zhttp://cogprints.org/id/eprint/155This item is in the repository with the URL: http://cogprints.org/id/eprint/1551997-08-20ZVigilance, Flock Size, and Flock Geometry: Information Gathering by Western Evening GrosbeaksVigilance (scanning) and other behavior patterns were studied in free-ranging Evening Grosbeaks (Coccothraustes vespertinus) at feeders to assess how flock size and flock geometry influenced the behavior of individual birds. The present results indicate that the way in which individual grosbeaks are positioned with respect to one another effects many aspects of their behavior, especially when a flock contains four or more birds. Birds in a linear array who have difficulty seeing one another, when compared to individuals organized in a circle who can easily see one another, are (1) more vigilant, (2) change their head and body positions more often, (3) react to changes in group size more slowly, (4) show less coordination in head movements, and (5) show more variability in all measures. These differences in behavior can be explained from a cognitive ethological perspective that favors intentional or representational explanations. Specifically, the data suggest that individual grosbeaks, when scanning and moving about, are visually monitoring the flock in which they are feeding and gathering information about a number of variables including flock size, what others are doing, where others are, which individuals are present, phenotypic features of flock members, food resources, or the location of potential predators. Individuals likely use visual records of the behavior and perhaps the phenotypic features of others, and this information influences various aspects of their behavior. Marc Bekoff1998-06-09Z2011-03-11T08:53:57Zhttp://cogprints.org/id/eprint/451This item is in the repository with the URL: http://cogprints.org/id/eprint/4511998-06-09ZW-learning: A simple RL-based Society of MindW-learning is a self-organising action-selection scheme for systems with multiple parallel goals, such as autonomous mobile robots. It uses ideas drawn from the subsumption architecture for mobile robots (Brooks), implementing them with the Q-learning algorithm from reinforcement learning (Watkins). Brooks explores the idea of multiple sensing-and-acting agents within a single robot, more than one of which is capable of controlling the robot on its own if allowed. I introduce a model where the agents are not only autonomous, but are in fact engaged in direct competition with each other for control of the robot. Interesting robots are ones where no agent achieves total victory, but rather the state-space is fragmented among different agents. Having the agents operate by Q-learning proves to be a way to implement this, leading to a local, incremental algorithm (W-learning) to resolve competition. I present a sketch proof that this algorithm converges when the world is a discrete, finite Markov decision process. For each state, competition is resolved with the most likely winner of the state being the agent that is most likely to suffer the most if it does not win. In this way, W-learining can be viewed as `fair' resolution of competition. In the empirical section, I show how W-learning may be used to define spaces of agent-collections whose action selection is learnt rather than hand-designed. This is the kind of solution-space that may be searched with a genetic algorithm.Mark Humphrys1998-03-12Z2011-03-11T08:54:07Zhttp://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 Pillard1998-09-06Z2011-03-11T08:54:15Zhttp://cogprints.org/id/eprint/738This item is in the repository with the URL: http://cogprints.org/id/eprint/7381998-09-06ZBook review of _The Egalitarians -- Human and Chimpanzee_ by Margaret PowerThis book combines some very interesting ideas with stunningly poor scholarship to create a potentially missleading book. Because the basic thesis -- that episodic extreme aggression seen among chimpanzees at Gombe and Mahale has been artificially induced by provisioning -- has been widely considered and parallels other criticisms of nonhuman primate data (e.g. debates over the 'naturalness' of langur infanticide), there is a risk people unfamiliar with the chimpanzee data will accept her conclusions uncritically. At the same time, her attempt to integrate developmental psychology with socioecology in humans and apes is interesting and it'd be a shame to dismiss that approach simply because of the poor application. Secondarily, the book should be of interest to historians of science because it maps so clearly onto the tradition of contrasting Rousseauian and Hobbesian views of (human) nature.Jim Moore1998-09-29Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/178This item is in the repository with the URL: http://cogprints.org/id/eprint/1781998-09-29ZIs the monkeys' world scientifically impenetrable?Cheney & Seyfarth (C&S) argue for a hybrid approach which 'place (empiricistic findings) tentatively within the framework of a more mentalistic approach'(p.9). The book is an important contribution to clarify the value and limits of the intentional approach in interpreting monkey behaviour, particularly C&S's excellent field work with vervets. But, unintentionally, it also demonstrates that cognitive science is more a perspective than a scientific discipline. In order to illustrate this, I shall consider the following topics: evolution of intelligence, concept formation, philosophy of scienceWinand Dittrich1998-09-06Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/177This item is in the repository with the URL: http://cogprints.org/id/eprint/1771998-09-06ZSociobiology and incest avoidance: a critical look at a critical reviewEprint summary: This short article points out a number of problems with treatment of data & theory in an earlier article by Gregory C. Leavitt in which he mis-cites mainly old papers on inbreeding in nonhumans to support his contention that the human incest taboo does not have a biological component/substrate.Jim Moore1998-11-15Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/180This item is in the repository with the URL: http://cogprints.org/id/eprint/1801998-11-15ZEnhancement of Opioid-Mediated Analgesia: A Solution to the Enigma of PlacentophagiaTwo major consequences of placentophagia, the ingestion of afterbirth materials that occurs usually during mammalian parturition, have been uncovered in the past several years. The first is that increased contact, associated with ingesting placenta and amniotic fluid from the surface of the young, causes an accelerated onset of maternal behavior toward those young. The second, which probably has importance for a broader range of mammalian taxa than the first, is that ingestion of afterbirth materials produces enhancement of ongoing opioid-mediated analgesia. The active substance in placenta and amniotic fluid has been named POEF, for Placental Opioid-Enhancing Factor. Recent research on both consequences is summarized, with particular attention to POEF, the generalizability of the enhancement phenomenon, its locus and mode of action, and its significance for new approaches to the management of pain and addiction.Mark B. Kristal2001-12-07Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1966This item is in the repository with the URL: http://cogprints.org/id/eprint/19662001-12-07ZOutcome of dyadic conflict in male green swordtail fish, Xiphophorus helleri: effects of body size and prior dominanceThe relative contribution of prior experience and of size asymmetries to the determination of dyadic dominance between unfamiliar individuals was examined using pairs of green swordtail fish, Xiphophorus helleri. Three experiments were conducted to assess the extent to which superiority in size could override potential handicaps resulting from prior experience. These results indicated that prior experience accounted for dyadic dominance when the size advantage of a previously subordinate over a previously dominant opponent was less than 25 mm2. However, as the lateral surface of the subordinate fish increased, neither previous experience nor size differences clearly accounted for the outcome of dyadic conflict. Even when the size advantage of subordinate opponents was in the 126-150 mm2 range, size differences did not adequately explain the outcome. In conflicts between large previously subordinate and smaller dominant fish, there was evidence for an inverse linear relation between the effects of size and the likelihood of establishing dyadic dominance. In general, males with prior experience as subordinates had to be at least 40% larger than a previously dominant fish to win a significant proportion of conflicts. These results indicate that prior agonistic experience and body size effects can be additive when at the advantage of one opponent. These factors can also cancel each other out when in opposition, at least when size differences are not extreme. The results also confirm the main effect of both factors as well as their interaction in the determination of conflict outcomes for X. helleri.
Jacques P. BeaugrandClaude GouletDaniel Payette2001-12-01Z2011-03-11T08:54:50Zhttp://cogprints.org/id/eprint/1942This item is in the repository with the URL: http://cogprints.org/id/eprint/19422001-12-01ZPrior residency and the stability of dominance relationships in pairs of green swordtail fish Xiphophorus helleri (Pisces, Peociliidae)The stability of dominance relationships between pairs of male Green Swordtail fish was followed daily for 20 consecutive days. In one experimental sample composed of 21 pairs, dominance of one of the fish had been favoured on the first day by giving the fish prior familiarity (prior residency) with the aquarium where it was to meet an intruder. In a control sample composed of 12 pairs, two intruders met in an unfamiliar aquarium. It was expected that the advantage given to the dominant by familiarity with the aquarium on the first day would disappear as the subordinate acquired in turn familiarity with the milieu. In comparison with pairs composed of two intruders, this would show up by more frequent inversions of the initial dominance relationship in pairs composed of a prior resident and an intruder. Only two inversions occurred over the 20 days of follow up and they occurred equally in the experimental (5%) and control (8%) samples. These results confirm the great stability of dominance relationships in dyads and invalidate the hypothesis that the prior residency advantage would decay as the subordinate became familiar with the aquarium. Unexpectedly, 13 of the 66 (20%) fish died over the 20 days. Death equally occurred in both samples but 12 (92%) cases implied initial subordinates. The exception was an initial dominant which had become the subordinate pair member three days before death. Various hypotheses are suggested to account for the selective deaths of subordinates.
Jacques P. BeaugrandMartin Beaugrand1998-06-15Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/197This item is in the repository with the URL: http://cogprints.org/id/eprint/1971998-06-15ZRethinking the language bottleneck: Why don't animals learn to communicate?While most work on the evolution of language has been centered on the evolution of syntax, my focus in this paper is instead on more basic features that separate human communication from the systems of communication used by other animals. In particular, I argue that human language is the only existing system of learned arbitrary reference. While innate communication systems are, by definition, directly transmitted genetically, the transmission of a learned learned systems must be indirect. Learners must acquire the system by being exposed its the use in the community. Although it is reasonable that a learner has access to the utterances that are produced, it is less clear how accessible the meaning is that the utterance is intended to convey. This particularly problematic if the system of communication is symbolic -- where form and meaning are linked in a purely conventional way. Given this, I propose that the ability to transmit a learned symbolic system of communication from one generation to the next represents a key milestone in the evolution of language.Michael Oliphant2001-12-07Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1964This item is in the repository with the URL: http://cogprints.org/id/eprint/19642001-12-07ZSocial and spatial structure in brook chars (Salvelinus fontinalis) under competition for food and shelter/shadeSalmonids, outside their reproductive period, are seen to have two types of territory called "territorial mosaic" and "partial territory". The first aspect of this research aimed at identifying the type of territory established by mature brook chars in artificial streams. After this, the biological value of spacing out was studied with regard to two resources: food, and shelter/shade which gives protection. Three 5 X 1 X 1 m artificial streams were built on the edge of a natural brook which provided a continuous water supply. One hundred and fifty mature brook chars (Salvelinus fontinalis) taken from that brook were distributed into 30 colonies with 5 members apiece. Three experimental conditions were created, and 10 colonies were submitted to each of these. In the first experimental condition, the quality of shelter/shade differed in 3 sectors of the artificial streams, whereas the quantity of food remained the same for all 3. In the second experimental condition, the quality of shelter/shade was identical, while the quantity of food differed in the 3 sectors. In the last condition, conflict was created: the fish had to choose between an area which offered excellent shelter/shade but no food, one which provided ample nourishment but no shelter/shade, and one in which all those resources were present at intermediate levels. Observation of the 30 colonies revealed "partial territory" in all cases. These corresponded to more or less complete aggressive-dominance hierarchies. Almost every alpha established territory, and the number of territorial individuals progressively decreased throughout inferior ranks. Alphas had exclusive use of their territory. Lower-ranking individuals successfully defended their territory against their subordinates, but were unable to drive away higher-ranking conspecifics. Overall results also indicated that the highest-ranking brook chars in the aggressive-dominance hierarchies more frequently established their territories in sectors of the streams with good shelter/shade than in sectors with good alimentary conditions.Jean CaronJacques P. Beaugrand2001-12-05Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1962This item is in the repository with the URL: http://cogprints.org/id/eprint/19622001-12-05ZDES DIFFÉRENCES LIÉES AU SEXE DANS LES STRATÉGIES DE RÉPARTITION SPATIALE CHEZ DES POISSONS PORTE-ÉPÉE (XIPHOPHORUS HELLERi) MAINTENUS EN CAPTIVITÉThe swordtail fish is a species particularly abundant in fresh water of Mexico and Central America. It is an ovoviviparous species, not really territorial which shows nipright order. In this research, significant differences of spatial distribution have been found according to the position in the nipright order and according to the sex of the fish. These differences bind with two external variables: the presence of sexual partners and the space available for the fish. The dominating males prefer a space partition allowing access to the females more than a compartment allowing access to more space in volume. They also chase their subordinates in the contiguous compartment of the aquarium. Females swordtails prefer the bigger compartment independently of the presence of conspecific males. These results are discussed in the light of reproductive strategies particular to each sex.Pierre-Alain CotnoirJacques P. BeaugrandClaude Goulet2001-12-16Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1987This item is in the repository with the URL: http://cogprints.org/id/eprint/19872001-12-16ZAn experimental model of aggressive dominance in Xiphophorus helleri (Pisces, Poeciliidae)An experimental model was constructed using seven postulates derived from the experimental results of Zayan (1974, 1975a,b,c, 1976). The model specifies the relative importance of several asymmetries in predicting aggressive dominance in Xiphophorus helleri. These asymmetries concern differences between opponents with respect to: prior residence in the tested area (versus intrusion); immediate social experiences of dominance or submission; social isolation; individual familiarity and recognition. The predictions of the general model were checked experimentally and confirmed; a multiple orthogonal regression accounted for about 97% of the variance in our experimental results. The basic experimental results serving as postulates were confirmed and could be generalized; a new synthetic and predictive model was formulated concerning the determinants of aggressive dominance in Xiphophorus males. The following empirical generalisations were either confirmed or disclosed by the present study of opponents showing very small size differences: G1: The dominance propensity is significantly higher in resident individuals than in intruders. G2: The dominance propensity is significantly higher in previously dominant individuals than in previously submissive ones. G2 holds true for dyadic encounters between acquainted as well as between unacquainted pairmembers. G3: The dominance propensity is similar in previously dominant individuals and in previously isolated ones. G4: The dominance propensity is significantly higher in previously isolated individuals than in previously submissive ones. G5: G2 overrides G1 in both acquainted and unacquainted opponents. In general it was found that recent agonistic experience (victory or defeat) was much more important to explain future issues than familiarity with the meeting place. However, negative effects of recent defeat appeared diminished when the prior loser encountered on familiar ground a prior dominant or isolated but unacquainted opponent.Jacques P. BeaugrandR.C. Zayan1998-09-06Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/175This item is in the repository with the URL: http://cogprints.org/id/eprint/1751998-09-06ZThe evolution of reciprocal sharingGenetical models of the evolution of reciprocal altruism (as distinct from cooperation, mutualism, or nepotism) have difficulty explaining the initial establishment of an altruist gene in a selfish deme. Though potential mechanisms have been suggested, there is an alternative: much "altruistic" behavior may in fact be purely selfish in origin and consequently reciprocity need not be invoked to provide a selective benefit to the actor. _Sharing_ and _helping_ are fundamentally different behavior categories and should not be confused. Patterns of resource sharing in chimpanzees correspond to predictions made by a selfish model but not to those of a reciprocal altruism model, and many observations of human gift exchange are consistent with the selfish, but not the altruistic, model. This suggests that presumed hominid meat exchange may have been the result of competition, not altruism or even cooperation, and that evolutionary models of "altruistic" behavior should be treated with caution.Jim Moore1998-09-06Z2011-03-11T08:53:43Zhttp://cogprints.org/id/eprint/176This item is in the repository with the URL: http://cogprints.org/id/eprint/1761998-09-06ZFemale transfer in primatesIntergroup transfer by males is nearly universal among social primates. Furthermore, among the most frequently studied monkeys - savanna baboons and Japanese and rhesus macaques - females typically remain in their natal groups, so troops are composed of related matrilines. These facts strongly support two major theories: 1) that kin selection is a powerful force in patterning sociality (if one is to live in a group, one should prefer a group of one's relatives), and 2) that the ultimate explanation for intergroup transfer is the avoidance of inbreeding depression (though both sexes would prefer to live with kin, one sex has to disperse to avoid inbreeding and for a variety of reasons the losing sex is generally male). Substantial rates of transfer by females in social species with routine male transfer would cast doubt on both ideas. In fact, evidence reviewed here indicates that female transfer is not unusual and among folivorous primates (e.g., _Alouatta_, the Colobinae) it seems to be routine. In addition to casting doubt on the demographic significance of inbreeding avoidance and favoring mutualistic and/or game theory interpretations of behavior over nepotistic ones, this finding supports the hypothesis that predator detection is the primary selective pressure favoring sociality for many primates. Finally, while female bonding [_sensu_ Wrangham, R. W. (1980), _Behaviour_ 75: 262-299] among primates appears to be less common than generally believed, the observed correlation between female transfer and morphological adaptations to folivory provides empirical support for Wrangham's model for the evolution of female-bonded groups.Jim Moore2001-12-08Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1970This item is in the repository with the URL: http://cogprints.org/id/eprint/19702001-12-08ZSocial organization of small heterosexual groups of Green swordtails (Xiphophorus helleri, Pisces, Poeciliidae) under conditions of captivitySixteen populations, each of four male and four female green 'swordtail fish, were observed in 54 litre tanks separated into two unequal volumes by a partition allowing swimming from one area to another only at the surface. Each population was observed on 2 4 occasions, making a combined total of 50 observation periods of 2 hours each. Chase right orders, spatial positions as well as several agonistic and epigamic behaviour units were noted during each period of observation. Males and females apparently form distinct hierarchies which are perfectly linear and transitive in 68% and 42% of the cases respectively. Some dominance structures are incomplete, but no intransitivity is noted. Alpha males are much more aggressive than their isosexual subordinates. In females, the frequency of aggressive behaviour appears to be more proportional to the social rank of the initiator, but the number of chases received from other females is the best indicator of rank in the female hierarchies. Alpha males are responsible for 80% of all sexual activity and have privilege to behaviour leading to insemination with a high probability in 85 % of the cases. Females are not courted according to their position in the female hierarchy, nor to their size. In the two compartment situation of the present study, which allowed spacing out and visual isolation of the individuals, the alpha males occupied the larger area of the aquarium in the company of the four females while the three subordinate males were restricted to the smaller area, unaccompanied by any females. This spacing out pattern emerged with neat regularity from the data and was apparently caused and maintained by aggressive behaviour, especially by charges, initiated by the alpha male toward male rivals. However, it is not evident that the behaviour of the alpha male should be neatly qualified as territorial defence, since specific area linked dominance was never realized in the present study. The social scheme most readily applicable to the present social and spatial organization is the "one male to several females" system or monarchistic male hierarchy, in which one male becomes very dominant over the others, occupies the larger area and is also the sole individual to court the females and to attempt insemination (haremic). These results support the sociobiological theorem that to dominate is to have priority of access to the necessities of life and reproduction.Jacques P. BeaugrandJean CaronLouise Comeau2001-12-05Z2011-03-11T08:54:51Zhttp://cogprints.org/id/eprint/1961This item is in the repository with the URL: http://cogprints.org/id/eprint/19612001-12-05ZModèles de dominance et théorie de lévolutionFactors which contribute to the fact that an individual maintains a relationship of quality with its environment, and thus is well adjusted to it, are the same factors which favor its social dominance. In a context in which resources are limited or can become scarce, dominance orders get established because it is to the interest of individuals to compete, and because there exist individual differences in competitive ability due to various degrees of individual adaptation. Individuals which are less adapted learn to avoid futile confrontations with opponents which they assess as superior in adaptation to themselves in the light of acquired eco-socio-cognitive experiences. Social organization of a given species is a compromise between living alone and not being able to profit from the important advantages of living in a group, and living in group of which the major disadvantage is to have to compete with others. The biological value of social organization as a complex property emerging from sociosystems is that such an organization allows some individuals to reproduce more than others. The dominance structure plays a role similar to a filter which retains only the best adapted, a role identical to that of natural selection. Such a differential promotion of individuals which results from intrasexual rivalry furnishes the material to epigamic selection. Females, having interest to be more selective when it comes to choose their reproductive partner, develop preferences for certain types of males which maximize their chances of reproduction. This choice made by females is not necessarily the product of highly complex neurobiological activity but nonetheless it leads to the selection of dominant individuals, thus of those which are the best adapted within a given group.
Jacques P. Beaugrand1998-12-02Z2011-03-11T08:54:16Zhttp://cogprints.org/id/eprint/760This item is in the repository with the URL: http://cogprints.org/id/eprint/7601998-12-02ZSuppression of infanticide in mother ratsIn order to test the hypothesis that infanticidal tendencies are suppressed when rats become mothers, very young newborn pups, either naturally born or cesarean-delivered, were presented to virgin females and to newly delivered mothers. Provided that the pups were lively, uncleaned of fetal fluids or membranes, and presented without placentas, nearly all virgins killed and nearly all mothers did not. Newborns were also presented to Day 22 pregnant rats and to rats whose pregnancies had recently been surgically terminated. Large proportions of both groups either were nonkillers or were actively maternally responsive (and a smaller proportion were both) despite the fact that none of these rats had undergone parturition or cared for pups. These results indicate that, independent of its effect on maternal caretaking, pregnancy suppresses infanticide in previously infanticidal nulliparae even before they become mothers. Hence, infants are protected from their own parents. In addition, evidence was obtained in support of the idea that freshly delivered pups have stimulus properties that make them specially suited for promoting the onset of maternal caretaking.L. C. PetersM. B. Kristal2001-06-08Z2011-03-11T08:54:40Zhttp://cogprints.org/id/eprint/1548This item is in the repository with the URL: http://cogprints.org/id/eprint/15482001-06-08ZDiscriminatory approach to auditory stimuli in Guinea fowl (Numida meleagris) after hyperstriatal/hippocampal brain damageIntroduction:
The dorsomedial hyperstriatum accessorium (DMHA) appears to mediate some functions simialr to the mammalian hippocampus on tests in the visual modality ( Oades 1976a, 1976b). Here we investigate similar attention-related functions in the auditory modality after brain damage in and around the avian hippocampus. To what extent do these functions extend posterior to the posterior commissure (parahippocampus) and relate to the apparent hierarchical function reported from auditory areas that are adjacent posteriorly (e.g. Field L) ?
Methods:
Operation: Aspiration lesions and cuts were made to discrete parts of the hyperstriatum/hippocampus anterior and posterior to the posterior commissure in adult birds: the performance of these two lesion groups was compared with sham-controls..
Training/testing: Guinea fowl were trained to approach, feed and retreat from a food dish after hearing a species-specific food-trill. An ethogram including approach, search, locomotion and tension behaviour was recorded before and after operation for a training and test regime of variations of the natural calls and other sounds
Histology is shown in figure 1 : Sonograms of fast-, slow, novel-, arousal-trills and "watch-winding" are shown in figure 2 : Photographs and Sketches of the behavioural responses are shown in figure 3.
Results:
1/ Both groups with anterior and posterior lesions showed impaired recognition of the stimulus variations, shown a) by more search behaviour in both groups, and b) increased approach tendencies in the posterior-lesion group.
[Nonetheless test stimuli were rcognized to be different - e.g. search after extinction > after filtered trills > after novel stimuli]
2/ Extended approach after posterior-lesions was followed by a long period of arousal / high tension.
3/ Transient tension behaviour after anterior damage habituated rapidly - search behaviour changed to low tension..
[The anterior lesioned group responded with search to filtered trills - there was message content still in the stimulus, whereas the posterior group changed behaviour.]
Conclusions:
It is proposed that after anterior hyperstriatal damage (hippocampus) there were changes in the thresholds for matching specifications of learned stimuli with new sensory input - initial activation was followed by disengagement.
In contrast more posterior damage incurred an impairment to the general rules for the selection of sensory input - hence this led to more generalised approach and arousal responses.
In conclusion there is a hierarchy of associative function extending anterior from the sensory field L, and this is discussed in terms of the function impaired after brain damage - perseveration (gross behavioural consequences) and persistence (application of recognition units to patterns of sensory stimulation).
Oades1998-11-19Z2011-03-11T08:54:16Zhttp://cogprints.org/id/eprint/757This item is in the repository with the URL: http://cogprints.org/id/eprint/7571998-11-19ZPlacentophagia: A biobehavioral enigma (or De gustibus non disputandum est)Although ingestion of the afterbirth during delivery is a reliable component of parturitional behavior of mothers in most mammalian species, we know almost nothing of the direct causes or consequences of the act. Traditional explanations of placentophagia, such as general or specific hunger, are discussed and evaluated in light of recent experimental results. Next, research is reviewed which has attempted to distinguish between placentophagia as a maternal behavior and placentophagia as an ingestive behavior. Finally, consequences of the behavior, which may also be viewed as ultimate causes in an evolutionary sense, are considered, such as the possibility of beneficial effects on maternal behavior or reproductive competence, on protection against predators, and on immunological protection afforded either the mother or the young.Mark B. Kristal1998-12-03Z2011-03-11T08:54:16Zhttp://cogprints.org/id/eprint/761This item is in the repository with the URL: http://cogprints.org/id/eprint/7611998-12-03ZLearning in escape/avoidance tasks in female rats does not vary with reproductive conditionTo determine whether the development of novel stimulus-response associations by the mother during the periparturient period is attributable to a general facilitation of learning produced by the hormonal milieu during that period, learning ability under various reproductive conditions was assessed in two tasks unrelated to the periparturitional situation. The two tasks, selected because they equalized the various groups for motivation and performance variables, were acquisition of a water-maze escape (including two reversals), and acquisition and retention of an unsignalled shuttlebox shock avoidance. The groups tested in the water maze were a midpregnant group, an immediately prepartum group, and an immediately postpartum group. In the shuttlebox, the same conditions (different rats) were compared, together with a nonpregnant estrus condition, and a nonpregnant diestrus condition. The results of both experiments indicate that although learning occurred, the characteristics of acquisition and retention were not influenced by reproductive condition.Mark B. KristalSeymour AxelrodMichael Noonan