Brian Sullivan

Psychopaths are not only impulsive, their brains are wired
to take risks and seek out rewards at any cost, claim researchers at Vandabilt University..


So while it’s known that psychopaths lack fear, empathy and
interpersonal skills, a disruption in the brains dopamine reward circuitry wants money, sex, or fame, in extreme ways.


By uncovering the role of the brain’s reward system in psychopathy, the study published in Nature Neuroscience,opens  a new area of study forunderstanding what drives these individuals.


“Psychopaths are often thought of as cold-blooded criminals
who take what they want without thinking about consequences,” said lead author Joshua Buckholtz,a graduate student in the Department of Psychology.


“We found that a hyper-reactive dopamine reward system may be the foundation for some of the most problematic behaviors associated withpsychopathy, such as violent crime, recidivism and substance abuse.”


Whilst it has been known that psychopathic individuals, this study focused onstudying their abundant impulsivity, heightened attraction to rewards and risk taking.

It's these impulsive excessive behaviors that are closely linked with the violent and criminal aspects of psychopathy.



“There has been a long tradition of research on psychopathy that has focused on the lack of sensitivity to punishment and a lack of fear, but those traits arenot particularly good predictors of violence or criminal behavior,” said associateprofessor of psychology and psychiatry, David Zald, a study co-author.


 “Our data is suggesting that something might be happening on the other side of things. These individuals appear to have such a strong draw to reward—to the carrot—that itoverwhelms the sense of risk or concern about the stick.”

To examine the relationship between dopamine and psychopathy, the researchers used positron emission tomography, or PET, and blood oxygen level–dependent

functional magnetic resonance imaging (fMRI ) to measure the brains dopamine release to probe of the brain’s reward system.

“The really striking thing is with these two very different techniques we saw a
very similar pattern—both were heightened in individuals with psychopathic traits,” Zald said.

Volunteers were given a personality test to determine their level of psychopathic traits.

Psychopathic  traits exist in a spectrum, violent criminals falling at one end of the spectrum to the manipulativeness, egocentricity, aggression and risk taking of a "normal" person.

First, the researchers gave the and then PET was used to view dopamine release after volunteers the had speed. In a second test, the volunteers were told they would receive a monetary reward for completing a simple task. While performing it their brains were scanned.

“Our hypothesis was that psychopathic traits are also linked
to dysfunction in dopamine reward circuitry,” Buckholtz said.

“Consistent with what we thought, we found people with high levels of psychopathic traits had almost four times the amount of dopamine released in response to amphetamine.”

Individuals with elevated psychopathic traits the dopamine reward area of the brain, the nucleus accumbens, was much more active while they were anticipating
the monetary reward than in the other volunteers.

“It may be that because of these exaggerated dopamine responses, once they focus on the chance to get a reward, psychopaths are unable to alter their attention until they get what they’re after,“ Buckholtz said.

As Professor Zald said “It’s not just that they don’t appreciate the potential threat, but that the anticipation or motivation for reward overwhelms those concerns.”

In the past, substance abuse has been associated with alterations in dopamine responses and psychopathy is strongly associated with substance abuse.
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