Visual P300 in treatment-resistant schizophrenic patients

Although cognitive functioning in schizophrenia continues to be the focus o f considerable research, few studies have attempted to evaluate the cogniti ve functions of neuroleptic treatment-resistant schizophrenic patients. Red uced amplitude of the P300 event-related potential (ERP) is one of the most consistently reported cognitive abnormality in schizophrenia. We therefore sought to determine whether treatment-resistant schizophrenic patients are also characterized by a significant reduction in P300 amplitude, Subjects responded to an infrequent visual stimulus while ignoring binaurally presen ted auditory stimuli. No group differences were observed for reaction time or P300 amplitude. The percentage of correct responses was excellent for al l subjects, although controls were more accurate. (C) 1999 Academic Press.