Abnormal Processing of Affective Words by Psychopaths

Abstract

We tested the hypothesis that psychopathy is associated with abnormal processing of affective verbal material. Criminal psychopaths and nonpsychopaths, defined by the Psychopathy Checklist, performed a lexical decision task ("Is it a word or not?") while we recorded reaction time and event-related potentials in response to letter-strings consisting of affective and neutral words and pronounceable nonwords. On the assumption that they do not make efficient use of affective information, our primary prediction was that psychopaths would show less behavioral and event-related potential differentiation between affective and neutral words than would nonpsychopaths. The results were in accordance with this prediction. The lexical decisions of nonpsychopaths were significantly faster, and relevant event-related potential components were significantly larger, to affective words than to neutral words. In sharp contrast, psychopaths failed to show reaction time facilitation or larger amplitude event-related potentials to affective words. We suggest that psychopaths extract less information from affective words than do other individuals. Possible implications of these and related findings for understanding the behavior of psychopaths are discussed.