• Affective Traits of Psychopathy and the Role of Early Visual Attention: An Electrophysiological Study

      Weissflog, Meghan; Department of Psychology
      Models of affective processing abnormalities in psychopathy have involved both amygdala abnormalities and attentional deficits to peripheral affective information. Neurophysiological bases for the latter are not currently well understood. Often presented as competing explanations for affective traits of psychopathy, these models may instead be compatible, describing different levels of analysis, with the amygdala playing a role in early attention allocation. To explore this possibility, this dissertation was designed to integrate these two areas of the literature by proposing a neurophysiologically-based model of biases in attention to peripheral affective information in psychopathy. This model is centred on the idea that attentional biases seen in psychopathy may result from reduced responsivity of a subcortical thalamus-amygdala circuit that influences the allocation of attention to salient stimuli in the environment during initial stages of processing. Event-related potential (ERP) components that reflect attention allocation during early stages of visual information processing were used to test the hypothesis that individuals high in psychopathic traits would show reduced attention allocation to peripheral information in the form of reduced and/or delayed ERP responses. Explored were the relations between psychopathic personality traits and early ERP responses to simple stimulation of the visual system (Study 1) and to spatially-filtered emotional faces involving implicit versus explicit processing of the stimuli (Study 2). ERP effects related to overall psychopathic trait severity, but also yielded factor-specific ERP response patterns. Study 1 results were consistent with the present hypotheses. Specifically, higher Factor 1 scores (primary, affect-based traits) were associated with reduced attention-related ERP amplitudes in response to a flash stimulus presented peripheral to task performance. Factor 2 severity (secondary antisocial and behavioural traits) was associated with ERP latencies in primary visual cortex. Study 2 also showed somewhat more complex but Factor-specific patterns of early visual processing. Overall, the results were consistent with a reduced responsivity of the thalamo-amygdalar pathway in psychopathy-related individual differences in attention at early stages of visual information processing, both for affective information and simple sensory stimulation. This raises the question of whether such processing differences are a predisposing factor for the development of psychopathic traits.
    • Using the HEXACO to Capture Psychopathy: Development and Initial Validation of the Power Proxies of Psychopathic Traits

      Power, Jordan P.; Department of Psychology
      Psychopathy, though often considered an abnormal personality construct, has been repeatedly found to be related to “normal” personality traits, and the HEXACO model of personality is particularly capable of capturing the “dark” personality variance integral to the construct. Additionally, while previous research indicates that psychopathy can be applied to both sexes, it has been suggested that psychopathic traits are expressed somewhat differently between men and women. In Study 1, we examined the relations between the Self-Report Psychopathy Scale (SRP) and the HEXACO-60 in a student sample (n = 1,346) in order to create proxy measures for Hare’s two-factor/four-facet model of psychopathy and to investigate sex differences in the associations between the SRP and the HEXACO. We created “general” proxies for use with samples of men and women in addition to male- and female-specific proxies for potential use with samples of exclusively men or women, respectively. The proxies had good psychometric properties and had stronger correlations with several psychopathy-relevant variables than did a previous attempt to measure the SRP facets using HEXACO items. In Study 2, we investigated how the proxies would function in a youth community sample (n = 396). The proxies related to many external variables in a similar manner as that of a previously validated measure of psychopathic traits in youth, suggesting that the proxy scales can be used with younger populations. In Study 3, we used a MTurk sample (n = 471) to update the proxy scales with HEXACO-100 items and to investigate sex differences in the relations between the SRP and the new HEXACO items. Several items were added to each version of the proxy scales and, compared to the original proxies, the updated proxies displayed better psychometric properties and stronger correlations with psychopathy-relevant variables. Overall, this program of research demonstrates considerable overlap between Hare’s model of psychopathy and the HEXACO model of personality. Honesty-Humility and altruism seem to underlie all of the psychopathy scales, whereas aspects of the other HEXACO domains tend to differentiate the psychopathy scales from one another. Further, several sex differences in how psychopathic traits relate to basic personality were identified.