Reconciling discrepant findings for P3 brain response in criminal psychopathy through reference to the concept of externalizing proneness

Abstract

We sought to address inconsistencies in the literature on amplitude of P3 brain potential response in offenders diagnosed with psychopathy. These inconsistencies contrast with the reliable finding of reduced P3 in relation to externalizing tendencies, which overlap with impulsive-antisocial features of psychopathy, as distinguished from the affective-interpersonal features. Employing a sample of incarcerated male offenders (N = 154) who completed the Psychopathy Checklist-Revised along with a three-stimulus visual oddball task, we tested the hypothesis that impulsive-antisocial features of psychopathy would selectively exhibit an inverse relationship with P3 amplitude. Clear support for this hypothesis was obtained. Our findings clarify the discrepant findings regarding psychopathy and P3, and establish P3 as a neurophysiological point of contact between psychopathy and externalizing proneness from the broader psychopathology literature.

Keywords: Antisocial behavior; EEG/ERP; Externalizing; P3; Psychopathy.

Figure 1

Average ERP waveforms for novel picture stimuli (left plots) and target ‘head’ stimuli (right plots) at electrode sites Fz, Cz, and Pz (upper, middle, and lower plots, respectively). High and Low PCL-R Antisocial groups consist of participants within the study sample falling within the upper and lower quartiles, respectively, of scores on the Antisocial Behavior facet of the Psychopathy Checklist-Revised (Hare, 2003).

Figure 2

Mean novel P3 amplitude elicited during the first and second half of the task. High and Low PCL-R Impulsive-Irresponsible groups consist of participants within the study sample falling within the upper and lower quartiles, respectively, of scores on the Impulsive-Irresponsible Lifestyle facet of the Psychopathy Checklist-Revised (Hare, 2003).