It is well known that psychopaths can commit violent, and often criminal, acts. But the precise neural mechanisms that underlie this behavior have remained elusive. However, new research reveals the neural circuits that may drive psychopathic behavior. Share on Pinterest New research may change how we perceive psychopaths, as the brain wiring that drives psychopathic behavior is revealed. What goes on in the mind of a psychopath? From specialized neuroscientific studies to popular psychology books, this head-scratching question has preoccupied scientists, ethicists, and journalists alike for years. While it is known that psychopaths sometimes display violent or criminal-like behavior, the neurological underpinnings of this condition have remained somewhat of a mystery. But a team of researchers from Harvard University in Cambridge, MA – led by Joshua Buckholtz, an associate professor of psychology – recently set out to unravel some of this mystery. By examining the brain scans of almost 50 inmates in two medium-security prisons in Wisconsin, Prof. Buckholtz and his team examined what makes psychopaths act the way they do, as well as what drives their decision-making. We may not yet know what goes on in the mind of a psychopath, but the new findings – which are published in the journal Neuron – may help us to understand what goes on their brain.

Studying psychopaths in prisons As the authors explain, previous studies have pointed to an association between the impulsive-antisocial factor and reward-anticipating circuits in the brain, as measured by blood-oxygen-level-dependent signaling, which is a standard technique used in functional MRI. For example, some studies have found a higher volume of striatal gray matter in teenagers with impulsive-antisocial symptoms, as well as in psychopathic offenders. Additionally, Prof. Buckholtz and team have shown in a previous study that scoring highly on the impulsive-antisocial scale correlated strongly with dopamine-releasing circuits and increased brain activity in areas associated with reward anticipation – namely, the nucleus accumbens. All of these studies suggested to the researchers that psychopathic behavior may be associated with excessive dopamine transmission and a stronger “functional reactivity to rewards” in the striatum. So they set out to investigate whether or not their hypothesis was correct. As part of the study, 49 inmates were asked to complete a so-called delayed gratification test while their brains were scanned using mobile scanners. In the test, participants had to choose between receiving a small amount of money right away and being given a larger amount later on. The researchers then estimated the subjective value that each of the two options presented to the participants. The sum of these subjective values was fed into a model based partially on studies carried out in primates. The model enabled the scientists to measure the impulsivity of the participants’ choices, as well as to detect the brain areas that are key in judging the value of these choices. The researchers also examined the inmates’ psychopathic characteristics using a traditional psychopathy test called the Hare Psychopathy Checklist-Revised.