Neuropsychological and oculomotor correlates of spatial working memory performance in schizophrenia patients and controls

Recent reports of spatial working memory deficits in schizophrenia provide evidence for dorsolateral prefrontal cortical (DLPFC) dysfunction. However, the question of how spatial working memory performance relates to other ta sk impairments in schizophrenia considered reflective of frontal dysfunctio n, such as the Wisconsin Card Sorting Test (WCST) and smooth pursuit eye tr acking, has been largely unexplored. Spatial working memory, as measured by a computerized visual-manual delayed response task (DRT), was evaluated in 42 schizophrenia patients and 54 normal controls. Subjects also completed a battery of neuropsychological and oculomotor tasks. Schizophrenia patient s performed as accurately as controls on a no-delay, sensory-motor control condition, but showed a significant impairment in spatial accuracy with the addition of an 8-s delay and verbal distraction task. For the patients, wo rking memory impairment was associated with fewer categories on the WCST, i mpaired eye tracking, fewer words learned on the Rey Auditory Verbal Learni ng Test, but not with measures of general cognitive and clinical functionin g. Results suggest the presence of a sub-group of schizophrenia patients wi th common pathophysiology that accounts for the co-variance of several task s implicating prefrontal dysfunction. (C) 1999 Elsevier Science B.V. All ri ghts reserved.