Functional imaging--schizophrenia.

Abstract

Evidence from recent studies of brain function in schizophrenia confirms that the frontal underactivity reported in earlier studies is a feature only of cases with decreased psychomotor activity, while patients with different symptom profile have different patterns of cerebral activity. Each of the three major groups of schizophrenic symptoms reflects a specific pattern of aberrant cerebral activity in association cortex of frontal, parietal and temporal lobes, and in related subcortical nuclei. These patterns indicate imbalances between neuronal activity at diverse interconnected brain sites, rather than abnormal function at a single location. Furthermore, during the performance of executive tasks, schizophrenic subjects exhibit impaired frontal activation, while during memory tasks there a tendency towards impaired temporal lobe activation. The difficulty activating a particular region does not reflect fixed loss of function. Rather the evidence indicates that the characteristic feature of schizophrenia is disturbed connectivity between cerebral areas.