ABNORMALITY OF SMOOTH-PURSUIT EYE-MOVEMENT INITIATION - SPECIFICITY TO THE SCHIZOPHRENIA SPECTRUM

Schizophrenia patients have a deficiency of smooth pursuit eye movemen t initiation. We addressed whether this deficit is specifically relate d to a predisposition for schizophrenia. Thirty-two relatives of schiz ophrenia patients, eight schizotypals, 13 psychiatric comparison, and 33 nonpsychiatric subjects were assessed on smooth pursuit initiation. The nonpsychiatric subjects had significantly higher eye acceleration s than did subjects in the other three groups, who did not significant ly differ. The relatives were subdivided into three groups: (a) those with a schizophrenia spectrum disorder (n = 4) performed similarly to the schizotypals; (b) those with a major depression history (n = 7) we re similar to the psychiatric comparison subjects; and (c) those with no psychiatric history differed from the nonpsychiatric subjects only on 30 degrees/s targets. There was also a significant relationship bet ween offspring and parent eye accelerations to 30 degrees/s targets (r = .476). These results suggest that pursuit initiation deficits may b e associated with a nonspecific, genetically transmitted neurological abnormality among schizophrenia spectrum disorder subjects.