Inefficiency of post-error adjustment in impulsive violent offenders.

Criminal offenders who show repeated impulsive violent behavior are often described as having impairments in both inhibitory control and error processing. A sample of such offenders was compared with controls using event-related potentials recorded during the performance of a combined flanker and stop-signal task with the aim of investigating the underlying mechanisms that may contribute toward such violent behavior by indexing conflict monitoring, error detection, and post-error processing. The results obtained indicated lower amplitude of the stop-signal N2 component for successfully inhibited trials, reflecting different degrees of inhibition in impulsive violent offenders, as well as a reduced Pe component over the parietal area, an indication of reduced awareness of errors. This is consistent with the behavioral data indicating a lack of post-error slowing compared with the control group. This suggests that these offenders have problems with error awareness, subjective error assessment processes, and the adjustment of future behavior.