164. Attenuated frontal activation during mental rotation in schizophrenia

Abstract

Patients with schizophrenia are impaired on tasks of occulomotor and haptic delay as well as visuo-spatial working memory, suggestive of frontal cortex abnormalities. Mental rotation tasks combine elements of visuo-spatial processing and working memory which requires the involvement of the central executive, localized to the frontal cortex. We used fMRI to investigate a mental rotation task in 5 dextral schizophrenic patients and 7 controls matched on age, IQ and handedness. We hypothesised that patients would have a deficit in mental rotation which will manifest as abnormalities in the BOLD signal in the frontal cortex. Schizophrenic subjects have intact basic spatial processing, therefore we predicted that occipital areas will be equally active in both groups while frontal regions of activation will be reduced or absent in the schizophrenic group.