Disorders of smooth pursuit eye movement and auditory N100 in schizophrenic patients

Attentional factors are thought to affect eye-tracking patterns. The present study examined the hypothesis that specific quantitative features of eye tracking would be correlated with the amplitude of a component of the auditory evoked potential, the N100, which is known to be enhanced by arousal and selective attention. We studied 12 clinically stable schizophrenic patients by means of DC-electro-oculography. The frequency and amplitude of different types of saccades (catchup, backup, anticipatory saccades, and square wave jerks) were assessed. The results suggest that small and large saccades, as classified by a simple amplitude criterion (4 degrees), have differential meanings and indicate that enhanced amplitudes of small saccades are an effect of arousal.