As Far as the Eye Can See: Relationship between Psychopathic Traits and Pupil Response to Affective Stimuli

Abstract

Psychopathic individuals show a range of affective processing deficits, typically associated with the interpersonal/affective component of psychopathy. However, previous research has been inconsistent as to whether psychopathy, within both offender and community populations, is associated with deficient autonomic responses to the simple presentation of affective stimuli. Changes in pupil diameter occur in response to emotionally arousing stimuli and can be used as an objective indicator of physiological reactivity to emotion. This study used pupillometry to explore whether psychopathic traits within a community sample were associated with hypo-responsivity to the affective content of stimuli. Pupil activity was recorded for 102 adult (52 female) community participants in response to affective (both negative and positive affect) and affectively neutral stimuli, that included images of scenes, static facial expressions, dynamic facial expressions and sound-clips. Psychopathic traits were measured using the Triarchic Psychopathy Measure. Pupil diameter was larger in response to negative stimuli, but comparable pupil size was demonstrated across pleasant and neutral stimuli. A linear relationship between subjective arousal and pupil diameter was found in response to sound-clips, but was not evident in response to scenes. Contrary to predictions, psychopathy was unrelated to emotional modulation of pupil diameter across all stimuli. The findings were the same when participant gender was considered. This suggests that psychopathy within a community sample is not associated with autonomic hypo-responsivity to affective stimuli, and this effect is discussed in relation to later defensive/appetitive mobilisation deficits.

Visual Behavior, Pupil Dilation, and Ability to Identify Emotions From Facial Expressions After Stroke

“…These areas were manually defined for each visual stimulus image, in accordance with previous studies (11,12,15,59). The averaged pupil diameter variation was also extracted, as in previous studies (18,60,61). The results of all the eye-tracking measures represent the averaged behavior of both eyes.…”

“…First, those images or baselines that presented a ratio of missing data >50% in either eye were discarded (23,60,62,63). Second, the first 2 s of the stimuli were also discarded to remove the initial pupil contraction (60). Third, the non-physiological variations in pupil size, identified as those changes occurring at a faster rate than 5 mm/s, were removed.…”

Assessing cognitive load using oculometrics to identify deceit during interviews

“…Additionally, as presented in Figure a, we used a gray image without color to reduce the effect of screen luminescence over pupil size (Kohn & Clynes, ), and a scramble filter was initially applied to each question to hide its meaning, as in Ho and Lu () study of image context. To ensure that the appearance of the interviewer—an attractive 37‐year‐old woman—did not act as a stimulus for any subjects and affect their pupil size (Burley et al, ), the interviewer used a microphone outside the view of the subjects.…”

“…The exciting stimulus of a pleasant image can also affect the pupil size of subjects (Burley, Gray, & Snowden, ). Previous studies have reached the conclusion that explicit stimuli, that is, a woman dressed in a bikini, has a higher impact in terms of pupil size change, compared with nonexplicit arousal stimuli, that is, a fully dressed person (Watts, Holmes, Savin‐Williams, & Rieger, ).…”

Triarchic psychopathy and deficits in facial affect recognition

“…These results indicate that psychopathy is associated with reduced attention to the eyes of affective faces. Another recent study investigated the relationship between pupil dilation and triarchic psychopathy and found that psychopathic traits were unrelated to emotion‐modulated pupil dilation (Burley, Gray, & Snowden, ). Together, these studies are part of a growing body of literature suggesting that psychopathy is not universally associated with facial affect recognition deficits.…”