Features that distinguish the smooth-pursuit eye-tracking performance of schizophrenic, affective-disorder, and normal individuals

Examined the eye-tracking records of 25 schizophrenic (mean age 37.6 yrs), 25 unipolar (mean age 37.9 yrs), 24 bipolar (mean age 36 yrs), and 46 medical control (mean age 35 yrs) patients. All the psychiatric patients were in symptom remission. All three psychiatric groups produced more oscillations than controls, and spiky tracking was correlated with poor performance as indexed by the production of large saccades. Schizophrenics did, however, produce smaller saccades and tracked with more phase lag than did each of the other groups. Results suggest that the smooth-pursuit system of schizophrenics is functionally different from that of normal people. Use of the phase lag as a potential marker of schizophrenia is discussed. (33 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).