Neuropsychological evidence for frontostriatal dysfunction in schizophrenia.
Schizophrenics and controls were compared on a computerized test of attentional set-shifting which provides a componential analysis of the Wisconsin Card Sort Test and has previously been shown to be sensitive to frontal lobe dysfunction and Parkinson's disease. The main test was of extra-dimensional shifting where subjects are required to shift response to an alternative perceptual dimension. In one condition, termed 'perseveration', subjects are required to shift to a novel dimension and ignore the previously relevant one. In the other condition, termed 'learned irrelevance', subjects are required to shift to the previously irrelevant dimension and ignore a novel one. Chronic medicated schizophrenics (N = 32) show a highly significant impairment on the perseveration but not the learned irrelevance condition, as compared to normal age and IQ matched controls (N = 24). This was true even of a subgroup of patients with preserved IQ. The impairments in attentional set-shifting failed to correlate with patients' scores on the Mini-Mental State Examination (mean; S.D. 26.8; 1.8) or with scores on a test of recognition memory. These results provide evidence for a specific deficit in a set-shifting test of executive function and support a hypothesis of frontostriatal dysfunction in schizophrenia.
D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001288:Attention / Q000187:drug effects / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000187:drug effects / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology; D008609:Mental Status Schedule / Q000706:statistics & numerical data; D008875:Middle Aged; D009483:Neuropsychological Tests; D011594:Psychometrics; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents