Adaptation to prismatic displacement by schizophrenics and normals.

A sample of schizophrenic inpatients and a control sample of normal volunteers, matched for age and sex were tested on two tasks before and after an exposure condition in which they pointed repeatedly to a target while viewing their hands and the target through prisms. Both groups showed significant changes in both tasks--judging the straight-ahead, and pointing to a single target without sight of the hands. The groups did not differ from each other in the amount of changes in straight-ahead judgments, but normals showed greater adaptive change in the pointing task. These results contradict earlier reports that schizophrenics fail to adapt to altered visual-proprioceptive inputs; but they also help distinguish between modes of proprioceptive utilization that do and do not differentiate schizophrenics from normals.