Psychopathic offenders' response to punishment
Adults with psychopathic personality disorder process information related to punishment and reward differently due to functional differences in their brains, according to a new study from researchers at the Institute of Psychiatry, Psychology and Neuroscience (IoPPN), published in Lancet Psychiatry.
Most violent crimes are committed by people with anti-social personality disorder (ASPD) and half the UK prison population meet the diagnostic criteria for this disorder. These individuals are ‘hot headed’ and so are aggressive, impulsive, and poor decision-makers. One third of those in prison with ASPD also meet the diagnostic criteria for psychopathy, and so are callous, lacking in empathy ('cold hearted'), grandiose and instrumentally aggressive, that is, they use aggression in a planned way to get what they want. The researchers used an fMRI scanner to trace the brain activity of adults with ASPD with and without psychopathy in response to punishment and reward tasks and found subjects with psychopathy had distinct differences in their responses to punishment information.
“We know that men with both antisocial personality disorder and psychopathy respond poorly to punishment across their lives: they seem to struggle to use punishment to change their behaviour. Until now we did not know why,” said senior author Dr Nigel Blackwood from the Department of Forensic and Neurodevelopmental Sciences, IoPPN. “The key is in their altered information processing system for punishment and reward information in comparison to antisocial men without psychopathy. This is the first study to show these differences in functional terms.”
The study comprised 12 violent offenders with ASPD and psychopathy, 20 violent offenders with ASPD but not psychopathy, and 18 healthy non-offenders. They completed a ‘reinforcement learning’ task in the fMRI scanner and researchers assessed their ability to adjust their behaviour (‘adaptive decision-making’) when the consequences of their responses changed from reward to punishment.
Dr Blackwood continued: “At the point at which something previously rewarded was now punished, we found abnormally increased activity in the posterior cingulate cortex and the anterior insula. Crucially, our findings suggest that offenders with psychopathy do not simply show reduced neural sensitivity to punishment and, instead, they show altered organisation of the information processing system responsible for reversal learning and adaptive decision making.
“This is similar to the findings in children with callous and unemotional traits. Childhood diagnostic schemes such as DSM-V already recognize the callous unemotional group of children, but adult diagnostic schemes do not, and lump all such men together as antisocial personality disordered. This means that in treatment terms we have a ‘one size fits all’ approach and this is wrong.”
Professor Sheilagh Hodgins, University of Montreal, and co-author on the paper added: “Our studies are providing insights into the neural mechanisms at work in adult violent offenders and so may be used, along with other findings, to design treatment to reduce reoffending. Conduct problems and the antecedents of psychopathy emerge early in life when learning-based interventions have the potential to alter brain structure and functioning. Future studies could focus on the development of psychopathy in children with callous and unemotional traits and, hopefully, improve childhood interventions to prevent violence and so create behavioural therapies which, in turn, could significantly reduce violent crime.”
This research was funded by grants from the Department of Health (the National Forensic Mental Health R&D programme), the Ministry of Justice (a DSPD programme grant), the Psychiatry Research Trust and the National Institute for Health Research Biomedical Research Centre and Dementia Unit at the South London and Maudsley NHS Foundation Trust and King’s College London.
Paper reference: Gregory, S. et al. ‘Punishment and psychopathy: a case-control functional MRI investigation of reinforcement learning in violent antisocial personality disordered men’ published in Lancet Psychiatry DOI: 10.1016/S2215-0366(14)00071-6
Lancet podcast: for an audio interview with Dr Blackwood click on this link.
For further information contact Tom Bragg, Press Officer at IoPPN, King’s College London, on +44(0)2078485377 or email tom.bragg@kcl.ac.uk