The effects of antipsychotic drugs and symptomatology on perceptual asymmetry in schizophrenia.

Perceptual asymmetry was measured in acutely psychotic schizophrenic patients and normal controls using a dichotic monitoring task. Although the schizophrenic group differed from the controls in terms of accuracy and speed of response, there were no significant group differences with respect to asymmetries in these variables. The pattern of responding in the schizophrenic group was also examined in relation to differences in symptomatology and antipsychotic drug administration. These variables, in isolation and in interaction with each other, were found to have a number of effects on both asymmetry and overall level of responding. The results were interpreted in the context of an information processing model of functional hemisphere asymmetry in schizophrenia, and the implications regarding the nature of schizophrenic symptomatology and the effects of antipsychotic drugs were discussed.