THE RELATIONSHIP BETWEEN SMOOTH-PURSUIT PERFORMANCE, MOTION PERCEPTION AND SUSTAINED VISUAL-ATTENTION IN PATIENTS WITH SCHIZOPHRENIA AND NORMAL CONTROLS

Background. In this study, we tested the hypothesis that low smooth pu rsuit gain in schizophrenia is related to an abnormality in motion per ception. Methods. The subjects were 19 schizophrenics treated with clo zapine and 19 controls. In addition to smooth pursuit and motion perce ption paradigms, sustained attention was also assessed using a continu ous performance task (CPT). Results. In the patient group, there was a statistically significant negative correlation between smooth pursuit gain and motion perception threshold (r = -0.60, P < 0.01). This rela tionship was not secondary to attention deficits as assessed by the CP T. Conclusions. Our results are consistent with the notion that the sm ooth pursuit gain deficit is related to a deficit in motion perception rather than in attention. Brain area V5 (also referred to as 'MT'in m acaque), located in the parieto-occipital region, is known to be criti cally important both for motion perception and gain. Thus, our results point to an abnormality in this area in schizophrenia.