Why does a normal looking human turn into a Jack the Ripper? According to dictionary a psychopath is a person with a horrible mental disorder that leads to violent, often murderous behaviour.
But thus far it has been near impossible to understand what happens in the brain that turns a human into a raging psychopathic murderer? However, new research led by a Harvard professor of psychology Joshua Buckholtz into the wiring (neural circuits) that drives psychopathic behaviour may unravel at least some of the mystery.
Dr Buckholtz and his examined the brain scans of about 50 inmates at prisons in Wisconsin to find out what makes psychopaths act the way they do and what drives their decision-making. Their findings were reported in the latest edition of Neuron.
The report points to an association between impulsive-antisocial factor and reward-anticipating circuits in the brain. Earlier studies had shown that the brains of individuals with high scores on the impulsive-antisocial behavioural scale are characterised by elevated levels of dopamine and heightened activity in nucleus accumbens, an area associated with reward anticipation.
They further revealed that violent behaviour is accompanied by much stronger “functional reactivity to rewards” in the striatum of psychopaths. Apparently this is the reason why psychopaths enjoy their murderous work so much!
In their study, Dr Buckholtz and his team asked 49 jail inmates to complete a delayed gratification test while their brains were scanned using mobile scanners. With their model the scientists were able to assess how impulsive the choices of the participants were and to detect the brain areas that are key in judging the value of these choices. The psychopathic characteristics of the subjects were evaluated using a traditional psychopathy test called the Hare Psychopathy Checklist-Revised.
The results confirmed the scientists’ hypothesis that the more psychopathic a person is, the greater is his magnitude of the rewards response, suggesting that the way they calculate the value of rewards is dysregulated.
Clearly, among psychopaths the area of the brain that calculates immediate rewards from an action is improperly or not at all governed by another area of the brain called the prefrontal lobe that is involved in social and moral decision-making, fear learning, and empathic responses. The vmPFC is also responsible for the ability to project the consequences of our actions and decisions into the future.
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