Smooth pursuit eye movements and neuropsychological impairments in schizophrenia

Smooth pursuit eye movements (SPEM) and neuropsychological performance were examined in a sample of 29 drug-treated schizophrenic patients and 22 healthy controls. Patients had impairment in SPEM as well as in a wide range of neuropsychological tests (Wechsler Adult Intelligence Scale, Wisconsin Card Sorting Test. Finger Tapping, Reaction time, Selective attention, Trail-Making and Simultaneous Capacity). Performance indices were more affected than strategy-executive indices. Drug type (clozapine vs typical) and dose (chlorpromazine units) were not related to neuropsychological impairment among the patients. Indices from the whole range of tests accurately predicted a subjects' group identity (patient vs control). Impaired SPEM was predicted more accurately by tests assessing frontal functions. Seven patients, all men, had only marginal neuropsychological impairments.