Neural basis of positive, negative, and controversial moral processing in incarcerated adult males with psychopathic traits

Background: Psychopathy is a disorder characterized by antisocial and affective traits and moral violations. It has developed over time from a general sense of moral insanity to a scientifically investigated personality disorder. Prior studies of psychopathy have found abnormal brain activity during moral processing in the amygdala, posterior cingulate, and basal ganglia; however, these studies only examined negatively valenced moral stimuli. Here we aim to replicate prior moral decision-making research in a forensic population and the differences between moral verdict and moral deliberation by psychopathy. We also aim to replicate prior psychopathy research on negative moral judgment and to extend this work by investigating positive and controversial moral stimuli and to investigate whether psychopaths can determine right from wrong. Methods: Incarcerated adult males (N = 245) completed a functional magnetic resonance imaging protocol on the Mind Research Network’s mobile imaging system. Psychopathy was assessed using the Hare Psychopathy Checklist-Revised (PCL-R). Participants were shown words describing three types of moral stimuli: negative (e.g., stealing), positive (e.g., giving to charity), and controversial (e.g., abortion). Participants rated each stimulus as “wrong” or “not wrong”. Results were modeled time-locked to stimulus presentation and separately to participant response. Results: PCL-R Total scores were correlated with “not wrong” responses to negative moral stimuli. PCL-R Total scores were also inversely related to hemodynamic activity in the middle temporal gyrus, basal ganglia, anterior cingulate, and temporal pole and positively related to greater activity in the anterior insula in the contrast of negative > positive. In the controversial > noncontroversial comparison, psychopathy was inversely associated with activity in the temporal parietal junction and dorsolateral prefrontal cortex. Stimulus-locked and response-locked models had few differences. Conclusions: Results support the paralimbic dysfunction hypothesis of psychopathy while demonstrating behavioral impairments and distinct patterns of positively and negatively valenced moral processing in psychopaths. It also indicates that deficits related to psychopathy in moral processing are more pronounced in response to controversial moral stimuli. Differences in deficiencies by psychopathy between moral verdict and moral deliberation are unclear.Research described here was supported by the National Institute of Mental Health and National Institute on Drug Abuse under Award Numbers R01MH070539, R01DA026964-03, and R01DA026505-01A1 to Kent A. Kiehl. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.PsychologyMastersUniversity of New Mexico. Dept. of PsychologyKiehl, KentKiehl, KentCalhoun, VinceClark, Vinc