The contingent negative variation in psychopaths.

There have been persistent claims that the contingent negative variation (CNV) is absent or greatly attenuated in psychopaths. However, these claims are based on a few studies with serious methodological and diagnostic problems. The present study attempted to avoid these problems. The subjects were male prison inmates divided into psychopaths and nonpsychopaths on the basis of scores on the Psychopathy Checklist. CNV was recorded while the subject performed a forewarned reaction time task with a relatively long interval (6 s) between the warning stimulus and the imperative stimulus. Motivation to perform well was ensured by having reaction times to the imperative stimulus determine how much money would be won or lost on a given trial. The early CNV of psychopaths was significantly larger than was that of the nonpsychopaths. There were no group differences in the late CNV or in reaction time. To the extent that the early CNV reflects processing of the warning stimulus and attention to task demands, the results are consistent with the hypothesis that psychopaths are proficient at focusing attention on events that interest them.