New research suggests psychopathic violent offenders have abnormalities in the region of the brain linked to learning from punishment.
The recent MRI study provides insight into the nature of violent psychopaths, the University of Montreal reported.
"One in five violent offenders is a psychopath. They have higher rates of recidivism and don't benefit from rehabilitation [programs]. Our research reveals why this is and can hopefully improve childhood interventions to prevent violence and [behavioral] therapies to reduce recidivism," said Professor Hodgins of the University of Montreal and Institut universitaire en santé mentale de Montréal.
Psychopathic criminals differ from regular criminals in that they have "low response to threats, are cold, and their aggression is premeditated."
To make their findings, the researchers used MRIs to study the brains of violent offenders in England, some of which were psychopaths and some of which weren't. They found structural abnormalities in both gray matter and specific white matter fiber tracts in both groups.
"We observed reductions in gray matter volumes bilaterally in the anterior rostral prefrontal cortex and temporal poles relative to the other offenders and to the non-offenders," Hodgins said.
The observed brain regions have been linked to empathy, pro-social emotions such as guilt and embarrassment, and moral reasoning. "Abnormalities were also found in white matter fiber tracts in the dorsal cingulum, linking the posterior cingulate cortex to the medial prefrontal cortex that were specifically associated with the lack of empathy that is typical of psychopathy," said study co-leader Nigel Blackwood.
The researchers noted it is important to learn from both real and imagined punishments in order to engage in appropriate social behavior. While inside the brain scanner, the subjects (which included non-offenders as controls) completed tasks that assessed their ability to adjust their behavior according to positive and negative responses. The research team found violent offenders failed to respond to punishment cues, and ultimately made poorer quality decisions despite longer periods of deliberation.
"We found that the violent offenders with psychopathy, as compared to both the violent offenders without psychopathy and the non-offenders, displayed abnormal responding to punishment within the posterior cingulate and insula when a previously rewarded response was punished. Our previous research had shown abnormalities in the white matter tract connecting these two regions. In contrast, the violent offenders without psychopathy showed brain functioning similar to that of the non-offenders," Blackwood said. "These results suggest the violent offenders with psychopathy are characterized by a distinctive organization of the brain network that is used to learn from punishment and from rewards."
The findings suggest individuals with psychopathy tend to only weigh the positive outcomes of a decision and tend to look over the potential consequences. This can cause the behavior to lead to a punishment instead of the reward the individual had expected.
The study's results could be used to design early intervention programs for children at risk of developing psychopathy. The study's results on the brain development of people with this psychological condition will most likely be tested in children in the future.
"Since most violent crimes are committed by men who display conduct problems from a young age, learning-based interventions that target the specific brain mechanisms underlying this [behavior] pattern and thereby change the [behavior] would significantly reduce violent crime," Hodgins concluded.
The findings were published under the title "Punishment and the Psychopath: an fMRI Investigation of Reinforcement Learning in Violent Antisocial Personality Disordered Men" in a recent edition of the journal Lancet Psychiatry.
