The startle reflex as an indicator of psychopathic personality from childhood to adulthood: A systematic review

Triarchic psychopathy and affective picture processing: An event-related potential study

Psychopathy and its precursors appear to be associated with abnormal affective response. For example, individuals high in psychopathy show reduced psychophysiological response to unpleasant stimuli, which might explain low levels of empathy in psychopathic individuals, and their pursuit of individual goals without regard for others' wellbeing. In keeping with the notion that psychopathology is best represented on a continuum, the triarchic model suggests that psychopathy is characterized by elevations on three traits: boldness, meanness and disinhibition. Understanding how these traits relate to psychophysiological response to emotional stimuli would help validate the triarchic model, while also bridging to other psychopathological spectra (e.g., internalizing psychopathology, which is characterized by low boldness). Here, N = 123 young adults passively viewed unpleasant, pleasant and neutral pictures while subjective and electrocortical response were recorded. Controlling for the other triarchic traits, individuals with higher self-reported meanness had smaller late positive potentials (LPPs) to both pleasant and unpleasant pictures, whereas individuals higher in boldness had larger LPPs to unpleasant pictures. In addition, those higher in meanness rated unpleasant pictures as more pleasant and less emotionally arousing. Disinhibition was not associated with the LPP or ratings. Meanness appears to drive blunted response to unpleasant pictures that has previously been observed among those high on psychopathy, and may also be associated with reduced engagement with generic pleasant stimuli. Moreover, results converge with prior work on other traits of transdiagnostic relevance (e.g., extraversion), as well as internalizing symptoms, providing a bridge between psychopathy and other forms of psychopathology.

Blunted startle reactivity in everyday sadism and psychopathy

Two studies examined the amplitude of the startle response as a function of the Dark Tetrad of personality (narcissism, Machiavellianism, psychopathy, and sadism). We measured electromyographic activity of the orbicularis oculi muscle evoked by a startle stimulus while participants viewed images on a computer screen. Both studies revealed a negative correlation between general startle reactivity (averaged across positive, negative, and neutral images) and sadistic tendencies. In Study 2, all four dark traits were negative correlates of general startle reactivity. Study 2 also examined the personality correlates of aversive startle potentiation (ASP; indexed by greater reactivity while viewing negatively-valenced images than positive or neutral images). ASP correlated negatively with a variety of personality measures of psychopathy and sadism, their facets, and related personality tendencies (callousness, risk-taking, and restricted affect). These findings suggest that ordinary people with high levels of callousness and antagonism display physiological evidence of non-reactivity (i.e., blunted acoustic startle in general), whereas psychopathy and sadism are preferentially associated with reduced ASP.

Low defensive cardiac reactivity as a physiological correlate of psychopathic fearlessness: Gender differences

Affective/interpersonal features of psychopathy have been consistently associated with diverse psychophysiological indicators of low threat sensitivity, suggesting an underlying deficit in the reactivity of the brain's defensive motivational system. This study examined the Cardiac Defense Response (CDR) -a complex pattern of heart rate changes in response to an aversive, intense, and unexpected stimulus- and its second accelerative component (A2), as a new physiological indicator of the fearlessness trait component of psychopathy. The differential contribution of dispositional fearlessness, externalizing proneness, and coldheartedness to the CDR pattern elicited during a defense psychophysiological test was examined in a mixed-gender sample of 156 undergraduates (62% women) assessed by the Psychopathic Personality Inventory-Revised (PPI-R). Higher PPI-R Fearless Dominance scores were related to lower heart rate changes throughout the CDR in women, but not in men. Further analyses on scales conforming the fearless dominance factor revealed that the hypothesized reduced A2 was specifically related to higher PPI-R Fearlessness scores only in women. Our findings provide initial evidence for the utility of the A2 to better understand the physiological aspects of fearlessness tendencies and its potential distinct manifestations across genders.

Attention-affect interactions and triarchic psychopathy: New electrophysiological insights from the late positive potential

One of the most prominent characteristics of psychopathy is a reduced processing of emotionally relevant information. However, it is still unclear how attentional mechanisms may modulate this deficit. The current study aimed to examine the impact of attentional focus on emotion processing in relation to the triarchic constructs of boldness, meanness, and disinhibition. Participants performed two tasks in which pleasant, neutral, and unpleasant framed pictures were presented. In the first task, participants were required to indicate the color of the frame (alternative-focus task), whereas in the second task they were instructed to indicate the emotional category of the image (affect-focus task). The Late Positive Potential (LPP) was used as an index of sustained engagement of attention to affective material. Confirming a successful task manipulation, we observed reduced LPP amplitudes, particularly for affective relevant material, in the alternative-focus task compared to the affect-focus task. Most interestingly, our results evidenced that trait meanness scores were associated with blunted elaborative processing of affective material (both appetitive and aversive) when this information was task-relevant (affect-focus task), but not when it was task-irrelevant (alternative-focus task). These findings indicate that high mean individuals are characterized by blunted elaborative processing of affective stimuli when their motivational relevance is determined in a top-down manner (i.e., when it is task-relevant). Our results highlight the need for further studying of the bottom-up and top-down dynamics of emotional attention in psychopathy.