According to researchers from South London and Maudsley NHS Foundation trust and the Institute of Psychiatry, Psychology and Neuroscience, adults that have psychopathic personality disorder process punishment and reward differently than normal adults because of systematic differences in their brains. The researchers’ studies involved 12 violent individuals diagnosed with anti-social personality disorder (ASPD) and psychopathy, 20 violent individuals diagnosed with ASPD but not psychopathy and 18 healthy non-offenders to serve as the control group. Those with ASPD are commonly hostile, quick to act on impulse and abysmal at decisions. Those with psychopathy are commonly characterized with a lack of empathy towards others and use aggression in order to obtain what they desire without caring about the impact of their actions on the well-being of others. The researchers’ reason for focusing on ASPD and psychopathy in individuals is due to the majority of violent criminal activity being done by people with ASPD. Additionally, half of the people in the prisons in the United Kingdom have met the diagnostic standards for having ASPD. A third of those with ASPD in prison also fit the criteria for psychopathy.
The study consisted of the individuals performing a “reinforcement learning task” while in a functional MRI scanner. The researched tried to evaluate the abilities of the members of the three groups to change their behavior, exhibit “adaptive decision-making”, when they started getting punished for actions that were previously rewarded. The researchers found that those with psychopathy did not merely have a reduction in neural sensitivity to the punishment but instead had different organizational structures in the brain systems responsible for processing information on reversal learning and adaptive decision making. The researchers concluded that the current classification of adult diagnostic schemes included a too large range of individuals with varying characteristics. This included psychopaths who had structural processing differences in their brains from other individuals. Treatment should then be made to be specific instead of general.
This study reminded me of the paper “The Role of Emotion in Decision Making”. In that study, individuals with impairments in the brain, specifically vmPFC lesion patients, chose actions detrimental to them even with foreknowing that harm would come onto them if they performed those actions. Like those with psychopathy, their brain processes the consequences of their actions differently and unlike normal individuals, they lack the same level of ability in choosing “good” actions.
Naqvi N, Shiv B, Bechara A (2006) The role of emotion in decision making: a cognitive neuroscience perspective. Curr Dir Psychol Sci 15:260 –264.