Pursuit eye movements in psychopathology: effects of target characteristics.

Tests of smooth pursuit eye movements using two types of targets, at three different frequencies, with two types of superimposed cognitive tasks were performed by 16 manic-depressive patients, 16 schizophrenic patients, and 14 normal subjects. The results showed that patients track more poorly than normals at all frequencies with either a real pendulum or an electronically driven target. Tracking efficiency of all subjects is improved by both superimposed cognitive tasks. Differences between patients and nonpatients exist under all experimental conditions.