Behavioural and neural correlates of emotion recognition as a function of psychopathic personality traits

Psychopathy is associated with well-known characteristics such as a lack of empathy and impulsive behaviour, but it has also been associated with impaired recognition of emotional facial expressions. The use of event-related potentials (ERPs) to examine this phenomenon could shed light on the specific time course and neural activation associated with emotion recognition processes as they relate to psychopathic traits. In the current study we examined the PI, N170, and vertex positive potential (VPP) ERP components and behavioural performance with respect to scores on the Self-Report Psychopathy (SRP-III) questionnaire. Thirty undergraduates completed two tasks, the first of which required the recognition and categorization of affective face stimuli under varying presentation conditions. Happy, angry or fearful faces were presented under with attention directed to the mouth, nose or eye region and varied stimulus exposure duration (30, 75, or 150 ms). We found that behavioural performance to be unrelated to psychopathic personality traits in all conditions, but there was a trend for the Nl70 to peak later in response to fearful and happy facial expressions for individuals high in psychopathic traits. However, the amplitude of the VPP was significantly negatively associated with psychopathic traits, but only in response to stimuli presented under a nose-level fixation. Finally, psychopathic traits were found to be associated with longer N170 latencies in response to stimuli presented under the 30 ms exposure duration. In the second task, participants were required to inhibit processing of irrelevant affective and scrambled face distractors while categorizing unrelated word stimuli as living or nonliving. Psychopathic traits were hypothesized to be positively associated with behavioural performance, as it was proposed that individuals high in psychopathic EMOTION RECOGNITION AS A FUNCTION OF PSYCHOPATHY 111 traits would be less likely to automatically attend to task-irrelevant affective distractors, facilitating word categorization. Thus, decreased interference would be reflected in smaller N170 components, indicating less neural activity associated with processing of distractor faces. We found that overall performance decreased in the presence of angry and fearful distractor faces as psychopathic traits increased. In addition, the amplitude of the N170 decreased and the latency increased in response to affective distractor faces for individuals with higher levels of psychopathic traits. Although we failed to find the predicted behavioural deficit in emotion recognition in Task 1 and facilitation effect in Task 2, the findings of increased N170 and VPP latencies in response to emotional faces are consistent with the proposition that abnormal emotion recognition processes may in fact be inherent to psychopathy as a continuous personality trait. EMOTION RECOGNITION AS A FUNCTION OF PSYCHOPATHY IV Acknowledgements First and foremost, I have to thank my advisor, Dr. Sidney Segalowitz, for the hours he has spent reading, reviewing, and otherwise helping me to shape this thesis into the work that it has become. Moreover, I would like to thank him for his insight, support and endless energy which have made my graduate experience more edifying and rewarding than I could ever have anticipated. I would also like to thank Jane Dywan and Angela Book, my committee members, for their continuous support and advice during the completion of this thesis. Your encouragement has been a motivating factor throughout this process, for which I am very grateful. In addition, I must thank my lab mates in the Brock University Cognitive and Affective Neuroscience lab, as just about every one of them has contributed to the completion of this thesis, be it through advice, technical assistance, theoretical discussions, or just some much needed distraction. In addition, I am very thankful for the wonderful cohort of incoming Master's students that I was so lucky to be grouped in with. This road would have felt much longer in didn't have such amazing people to share the trip with. Finally, I am forever grateful to my mom and my grandparents for everything they've done for me that has helped me to reach this point in my life. Along with the rest of the wonderful friends and family that I have been so lucky to have been graced with, words cannot express how much they have done to help and support me along the way. EMOTION RECOGNITION AS A FUNCTION OF PSYCHOPATHY v Table of