Antisaccades and smooth pursuit eye tracking and schizotypy.

Abstract

Eye tracking deficits are one of a few widely validated behavioral markers of risk for schizophrenia. Recently, it has been proposed that antisaccade performance may also constitute a marker of schizophrenia risk. This study investigated whether eye tracking and antisaccade deficits could be found in another population with putative liability to schizophrenia-nonclinical subjects with elevated scores on a psychometric index of perceptual aberrations. Subjects were 55 university students who received either high or normal scores on the Perceptual Aberration Scale, a measure of schizotypy indexing body image and perceptual distortions. Subjects completed a smooth pursuit eye tracking task and an antisaccade task. Eye movements were monitored using an infrared limbus tracker. Subjects with high Perceptual Aberration Scale scores (putative "schizotypes") had lower pursuit quality and a lower percentage correct on the antisaccade task than the controls. The 2 groups did not differ in antisaccade or error latencies. The increase in antisaccade errors in the schizotypes was accounted for almost entirely by an increase in perseverative errors, but virtually no difference between groups on random errors. Antisaccade performance was significantly related to pursuit quality. Subjects with elevated Perceptual Aberration Scale scores have performance deficits on oculomotor tasks that have been linked to latent liability to schizophrenia, namely, smooth pursuit and antisaccade performance. The antisaccade errors in the schizotype group were primarily perseverations, a behavioral pattern often associated with frontal lobe dysfunction and observed in the performance of schizophrenic patients.