Compromised speed discrimination among schizophrenia patients when viewing smooth pursuit targets.

Schizophrenia subjects' smooth pursuit abnormalities may reflect a problem with perception of motion, although evidence comes primarily from reports using stimuli that differ from standard smooth pursuit stimuli (i.e. moving gratings or coherent dots). This study presented schizophrenia and healthy subjects with a forced-choice speed discrimination paradigm using smooth pursuit-like stimuli. The schizophrenia subject's motion processing was impaired, as evidenced by their significantly higher speed discrimination thresholds (a difference that was 1.7 larger for the patient group). Abnormalities of motion perception in schizophrenia, even for simple stimuli, suggest a problem with motion processing in area MT.