Laterality in schizophrenia. A reaction time study.

A laterality study in schizophrenia was carried out by measuring reaction time (RT) in a baseline condition and while subjects were engaged in a concurrent task. In the baseline condition, a clinical measure of psychoticism was associated with differential slowing with the right hand in schizophrenic dextrals but not in a control group of affective dextrals. The concurrent task suppressed the effect of psychoticism on RT performance. The results suggest that left-hemisphere deficits in schizophrenia are state dependent, and so not necessarily due to cortical dysfunction.