Relation of neuroleptic dose and tardive dyskinesia to attention, information-processing, and psychophysiology in medicated schizophrenics.

Relationships of neuroleptic dosage and tardive dyskinesia with measures of attentional, information-processing, and psychophysiological dysfunctions in medicated chronic schizophrenics were explored by correlational and stepwise multiple-regression analysis. High neuroleptic dosage was found to be associated with increased reaction time, reduced span of apprehension, low basal skin conductance level, and reduced skin conductance reactivity. Severe abnormal involuntary movements were associated with increased eye-tracking dysfunction, increased scanning eye-movement rate, increased reaction time, and reduced skin conductance reactivity. These findings led to the hypothesis that neuroleptic dosage and tardive dyskinesia may be sources of error variance in the measurement of attentional, information-processing, and psychophysiological functions in schizophrenics.