Procedural learning in first episode schizophrenia investigated with functional magnetic resonance imaging.

OBJECTIVE: The present investigation assessed the severity, course, and cerebral implications of serial reaction time (SRT) procedural learning deficits in schizophrenia.
METHOD: Hemodynamic changes on fMRI were assessed during an SRT task in 17 unmedicated first episode psychosis (FEP) patients and matched healthy controls.
RESULTS: The groups demonstrated comparable procedural learning and associated activation of anterior cingulate cortex, subcortical structures, and many left frontal structures. The groups also demonstrated comparable increased activation of right parietal structures on trials with demands for spatial localization without procedural memory. Relative to healthy controls, the schizophrenia sample showed less activation of one region of the left middle frontal cortex and more activation of left superior temporal cortex on procedural trials, but more activation of right medial frontal cortex on localization trials.
CONCLUSIONS: Intact SRT procedural learning and normal or enhanced hemodynamic response in subcortical and right cortical structures diverges from prior results with medicated samples, suggesting a more focal cerebral dysfunction in the left middle frontal cortex before the onset of treatment.