?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Stimulus+dimension+shifts+in+patients+with+schizophrenia%2C+with+and+without+paranoid+hallucinatory+symptoms%2C+or+obsessive+compulsive+disorder%3A+strategies%2C+blocking+and+monoamine+status&rft.creator=OADES%2C+Robert++D.&rft.subject=Clinical+Psychology&rft.subject=Neuropsychology&rft.subject=Neuropsychiatry&rft.description=Introduction%3A+Reversal+and+intra-dimensional+(ID)+and+extra-dimensional+(ED)+non-reversal+shifts+in+task+discrimination+learning+were+compared.+The+aim+was+to+see+if+%22learned+inattention%22+to+the+irrelevant+dimension+differentially+influenced+the+efficacy+of+learning+and+of+the+stimulus+choice+strategy.+(An+overall+indicator+of+monoamine+metabolism+was+measured+for+potential+congruence+between+switches+of+attention+and+dopamine+activity%3A+see+Oades%2C+Neurosci.+Biobehav.+Rev.%2C+%2C+9%2C+261-283%2C+1985).%0A%0AMethods%3A+Performance+on+pattern-discrimination+discrimination+shifts+was+compared+with+conditioned+blocking+(CB%3A+another+test+of+%22learned+inattention%22)+and+related+to+the+status+of+monoamine+neurotransmitter+metabolism+reflected+in+24h-urine+samples+between+tests.+Results+are+reported+for+29+healthy+subjects+(mean+age+18.0y)%2C+13+patients+with+obsessive+compulsive+disorder+(OCD%3A+mean+age16.3y)%2C+and+28+with+schizophrenia%2C+including+14+paranoid+hallucinatory+(PH%3A+19.6y)+and+14+nonparanoid+patients+(NP%3A+17.5y).+%0A%0AResults%3A%0A1.+PH+and+NP+patients+improved+learning+with+practice+but+showed+an+impaired+shift+on+each+task.+%0A2.+Unlike+PH+and+control+subjects%2C+the+NP+shift+impairment+was+non-specific+and+related+to+their+problems+on+simple+reversal+of+the+discrimination.+%0A3.+The+length+of+the+stimulus-response+sequences+showed+that+all+subjects+were+able+to+acquire+a+set+for+colour.+%0A4.+An+analysis+of+choice+on+sequential+pairs+of+stimuli+showed+that+while+all+patients+showed+fewer+win-stay+sequences%2C+only+PH+patients+perseverated+with+lose-stay+sequences.+This+type+of+error+in+PH+patients+contrast+with+the+increase+of+win-shift+errors+in+NP+patients+(figure+1).+%0A5.+Learning+about+the+added+stimulus+on+the+CB+task+related+to+the+efficiency+of+intra-dimensional+shift+in+NP+patients.+%0A6.+An+impairment+with+OCD+patients+was+restricted+to+the+ED-shift+(not+reversal+or+ID-shift).+%0A7.+Increases+of+dopamine+activity+related+to+slower+initial+learning%2C+but+to+more+switches+(and+rapid+learning)+on+all+shift+tasks%3A+(positive+correlations+with+win%2Flose-shift%2C+negative+with+win-stay).+NA+activity+in+PH+and+NP+patients+related+to+increased+win-stay+and+decreased+lose-shift+decisions+(figure+1).+%0A8.+Increased+serotonin+activity+correlated+with+faster+learning+in+controls%2C+OCD+and+PH+patients.+But+the+opposite+relationships+for+dopamine+and+serotonin+activity+held+for+NP+patients+(figure+2).+%0A%0AConclusions%3A+%0AThe+different+tasks+of+the+%22learned+inattention%22+paradigm+have+different+if+related+requirements+and+correlates.+The+monoamine+data+are+consistent+with+the+postulated+function+of+noradrenaline+in+tuning+and+dopamine+in+switching+operations.+The+behavioural+data+are+consistent+with+the+automatization+of+endogenous+information+processing%2C+while+NP+patients+use+exogenous+attentional+strategies+fir+selecting+information+and+PH+patients+show+inefficient+endogenous+control+of+attention.%0A&rft.publisher=Elsevier&rft.date=1997&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F1138%2F2%2FBBR-oades.pdf&rft.identifier=++OADES%2C+Robert+D.++(1997)+Stimulus+dimension+shifts+in+patients+with+schizophrenia%2C+with+and+without+paranoid+hallucinatory+symptoms%2C+or+obsessive+compulsive+disorder%3A+strategies%2C+blocking+and+monoamine+status.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1138%2F