?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Impaired+attention-dependent+augmentation+of+MMN+in+nonparanoid+vs+paranoid+schizophrenic+patients%3A+a+comparison+with+obsessive-compulsive+disorder+and+healthy+subjects&rft.creator=OADES%2C+Robert+D.&rft.creator=DITTMANN-BALCAR%2C+Alexandra&rft.creator=ZERBIN%2C+Dieter&rft.creator=GRZELLA%2C+Ina&rft.subject=Clinical+Psychology&rft.subject=Neuropsychiatry&rft.description=Introduction%3A+Mismatch+negativity+(MMN)%2C+in+the+deviant-minus-standard+event-related+potential+(ERP)+difference-waveform%2C+may+represent+a+working+memory+trace+for+tone+differences+(a+deviant+among+a+sequence+of+standards).+Most%2C+but+not+all+studies+find+MMN+reduced+in+patients+with+schizophrenia.+%0AAims%3A+This+report+investigates+if+differences+may+be+attributable+to+experimental+condition+(diffuse+vs+focused+attention)%2C+component+identification+(N1-like+vs+N2-like)%2C+topographic+distribution+and+clinical+condition+(with+%2F+without+paranoid+-hallucinatory+symptoms%2C+PH%2FNP).+Comparisons+were+made+for+12+PH+and+12+NP+schizophrenic+patients+with+13+obsessive+compulsive+and+25+normal+control+subjects.+%0AResults%3A+Frontal+MMN+reduction+in+schizophrenics+largely+resulted+from+an+absence+of+an+increase+in+focused+attention+conditions+as+in+comparison+groups.+But+there+was+marked+activity+recorded+from+sites+over+the+temporal+lobe+in+NP+patients.+These+features+were+not+reflected+in+other+components+except+for+a+visible+but+nonsignifiant+N1-like+temporal+locus+in+NP+patients.+Further%2C+schizophrenic+patients+did+not+show+an+increase+in+late+positivity+with+focused+attention+like+the+comparison+groups.++%0AConclusions%3A+The+results+show+that+so-called+automatic+processing+deficits+in+schizophrenia+(amount+and+locus+of+MMN)+are+best+seen+in+situations+requiring+the+activation+of+controlled+attentional+processes.+It+is+suggested+that+impaired+processing+of+irrelevant+stimuli+and+reduced+frontal+MMN+in+NP+patients+may+reflect+reduced+dopaminergic+responsivity.%0A%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%2F1155%2F2%2Fbiopsychiat.pdf&rft.identifier=++OADES%2C+Robert+D.+and+DITTMANN-BALCAR%2C+Alexandra+and+ZERBIN%2C+Dieter+and+GRZELLA%2C+Ina++(1997)+Impaired+attention-dependent+augmentation+of+MMN+in+nonparanoid+vs+paranoid+schizophrenic+patients%3A+a+comparison+with+obsessive-compulsive+disorder+and+healthy+subjects.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1155%2F