TIMING AND AMPLITUDE OF SACCADES DURING PREDICTIVE SACCADIC TRACKING IN SCHIZOPHRENIA

Schizophrenia patients have ocular motor abnormalities. It has been hy pothesized that these abnormalities are associated with frontal eye fi eld pathology. If so, schizophrenia patients should have difficulties decreasing saccadic reaction times in response to predictably moving t argets. To evaluate the frontal eye field hypothesis, 25 schizophrenic and 26 nonpsychiatric subjects completed predictive saccadic tracking tasks. The groups demonstrated equivalent decreases in saccadic react ion times over consecutive trials. Schizophrenia patients, however, ha d faster reaction times and shorter amplitude saccades than nonpsychia tric subjects. The shorter amplitude saccades were made regardless of reaction time, perhaps an antipsychotic medication effect. The reactio n time results are unlikely to be an effect of treatment with antipsyc hotic medication and are inconsistent with the hypothesis that schizop hrenia patients have frontal eye field pathology.