Perceptual aberrations, schizotypy, and the Wisconsin Card Sorting Test

This study examined performance on the Wisconsin Card Sorting Test (WCST) by 23 schizotypic subjects and 28 normal control subjects. Schizotypy was measured on the Perceptual Aberration Scale (PAS). Overall, schizotypic (high PAS) subjects performed more poorly than control (low PAS) subjects on the WCST; specifically, schizotypic subjects showed deficits on the failure-to-maintain-set and number-of-categories indexes. Consistent with expectations based on research with high-risk subjects, schizotypic subjects were nearly 10 times more likely than controls to be included in a subgroup of deviant WCST performers identified by a composite performance index. WCST performance was not associated with current levels of anxiety or depression. Our results provide evidence for subtle WCST performance deficits in subjects hypothesized to be at risk for psychosis--perhaps schizophrenia--and are broadly consistent with current speculation about dorsolateral prefrontal cortex functioning in schizophrenia as well as recent speculation concerning spatial working memory and schizophrenia. The heuristic potential of our results is discussed and we encourage replication of the present study. Viewed in this context, our results are hypothesis-generating and do not provide definitive confirmation of specific hypotheses.