To explore the characteristics of cerebral activation during the performance of WCST in first-episode, drug-naive schizophrenic patients by functional magnetic resonance imaging,Wisconsin Card Sorting Test (WCST) and Color Card Sorting Test (CCST).

Twenty healthy adults and twenty schizophrenic patients underwent fMRI with a 1.5T MR imager with gradient echo-EPI sequence during the performance of Wisconsin Card Sorting Test (WCST) and Color Card Sorting Test (CCST). The functional images of two groups were analyzed with analysis software. The active volume of interested brain areas and the performance of WCST were compared between healthy group and patient group. Results:(1) The performance of WCST in first-episode drug-naive schizophrenic group were significantly lower than the performance in healthy group(P<0.01) . (2) The images subtracted the functional images of CCST from those of WCST in healthy group suggested that activations were mainly localized in the bilateral frontal lobe, especially the dorsolateral prefrontal cortex,posterior parietal cortices and anterior cingulate gyrus.(3)The patients group showed less activations in left dorsolateral prefrontal cortex(P<0.01), left anterior cingulated (P<0.05),but more activations in left posterior parietal cortices(P<0.05).

The dorsolateral prefrontal cortex and anterior cingulate of first-episode schizophrenic patients are hypofunction,which maybe involved in the executive function disorder in schizophrenia. The hyperactivity of posterior parietal cortices maybe can compensate the hypofrontality in a certain extent.