Oculomotor Pursuit in Schizophrenia

To the Editor.—  The presence of impaired eye-tracking in schizophrenic patients has been studied by Holzman et al,^1.2 Shagass et al,^3.4 and Kuechenmeister et al.⁵ These studies have also investigated the effects of age, sex, drugs, neuropathy, affective disorders, and perceptual-cognitive tasks on eye-tracking.Although these articles represent important findings, other factors appear to warrant further study. Questions arise as to whether lengthy tracking tasks used by previous studies might produce fatigue or inattention that could affect eye-tracking in schizophrenics. In addition, Young's observation⁶ that a velocity range exists in which accurate tracking for humans is optimal would support further study of the effects of target velocity on eye-tracking. A study was conducted to determine whether the reported deficiency in pursuit tracking by schizophrenics was a function of the target velocity and/or the duration of the tracking trial.Twelve male and five female schizophrenic patients participated.