An MRI study has revealed that psychopathic violent offenders have brain abnormalities in areas that influence learning from punishment.
In violent crimes, one in five offenders is a psychopath. These offenders do not benefit from current rehabilitation programs and are more likely to commit another crime. Identifying the neural mechanisms behind the persistent violent behavior of psychopaths can lead to more effective programs for prevention and rehabilitation.
The study, published in The Lancet Psychiatry, included 12 violent offenders with antisocial personality disorder and psychopathy, 20 violent offenders with antisocial personality disorder but no psychopathy, and 18 non-offenders who had neither disorder. The offenders were convicted of violent crimes including murder, rape, attempted murder, and grievous bodily harm.
While undergoing a functional MRI, each participant completed a task designed to see how they adjusted their behavior when the consequences of their actions changed from positive to negative. In the task, participants matched images. Sometimes they received points for making correct pairs, and other times they did not.
The violent offenders did not change their actions even as the consequences changed; they made poor decisions despite taking longer to decide what to do when compared with controls. When violent offenders with psychopathy were punished for an action that was previously rewarded, they showed abnormal responses in the posterior cingulate and insula compared with the responses of violent offenders without psychopathy and controls.
Additionally, those with psychopathy had decreased gray matter volumes bilaterally in the anterior rostral prefrontal cortex and temporal poles, areas that are associated with empathy, guilt, embarrassment, and moral reasoning. They also had abnormalities in white matter fiber tracts in the doral cingulum that were associated with lack of empathy.
The researchers hypothesize that those with psychopathy may make decisions differently than those without the condition. Usually, decision making involves considering both the positive and negative consequences and choosing the action that will most likely lead to a positive outcome. People with psychopathy may not consider negative consequences, possibly basing their actions only on potential positive consequences.
The conduct problems and symptoms associated with psychopathy can be seen early in life, and learning-based interventions can reduce these problems if performed early enough. The researchers hope that their insights into the brain structure of psychopaths can influence future studies of children, potentially helping identify and target children for early treatment.
- Gregory S, et al. Punishment and psychopathy: a case-control functional MRI investigation of reinforcement learning in violent antisocial personality disordered men. Lancet Psych. 2015; doi: 10.1016/S2215-0366(14)00071-6.