AN ASSESSMENT OF COGNITIVE INHIBITION IN SCHIZOTYPIC INDIVIDUALS

Abstract

This study examined the relationship between cognitive inhibition processes and the positive and negative symptoms of schizotypy. Priming and directed forgetting tasks were used to investigate whether participants who obtained high scores on schizotypy scales would show impaired inhibitory functioning as compared to controls who had low scores on these scales. Participants completed five questionaires. On the basis of their scores, they were divided into four groups: ( l) participants with high scores on all scales ('high schizotypes') (2) participants with high scores on scales measuring positive symptoms ('positive symptom schizotypes') (3) participants with high scores on scales measuring negative symptoms ('negative symptom schizotypes') and (4) participants with low scores on all scales ('low schizotype controls'). The participants also performed the priming and directed forgetting tasks, the former assessing automatic inhibition and the latter, intentional inhibition. Results indicated that positive symptom schizotypes displayed reduced priming effects as compared to the other groups. While the three schizotypic groups and the low schizotype controls showed directed forgetting, the effect was reduced in the former. It is therefore suggested that positive symptoms are associated with impaired automatic and intentional inhibition of irrelevant information while negative signs are only linked to the latter. The present study therefore provides new insights concerning the specificity of cognitive inhibition deficits as a function of the polarity of schizotypic symptomatology. It confirms the usefulness of a symptom oriented approach and provides some validation for the construct of schizotypy.