Emotional modulation of the pupil in psychopathy: A test of the Response Modulation Hypothesis

Some aspects of psychopathy may be underpinned by a deficit in processing emotional information, although there is evidence that this impairment only emerges when the affective cues are not central to ongoing goal-directed behaviour. However, this hypothesis has not been explored previously in relation to autonomic reactivity to emotional stimuli. The current study investigated this in a large (N = 174) community sample by examining changes in pupil diameter, a measure of autonomic nervous system activity, while participants viewed images that were either neutral in content or contained highly arousing/emotional content. Participants' attentional focus was manipulated across two tasks, such that participants either focused on whether the image contained emotional content (emotion-focus) or whether there were people present in the image (alternate-focus). Psychopathy was conceptualised via the Triarchic model of boldness, meanness and disinhibition. As expected, the arousing images caused greater pupil dilation compared to neutral images. However, the magnitude of this dilation was not moderated by any aspect of psychopathy regardless of the participant's attentional focus. It may be that reduced pupil reactivity to emotional stimuli is only expressed at high levels of psychopathy not normally found in community samples, or that participants with high traits of psychopathy in the community were still able to sufficiently attend to the emotional components of the images to overcome any autonomic deficits regardless of their attentional focus. Further research is needed to explore these possibilities.