Science Daily takes a close look at how psychopaths’ brains are shaped by rewards:
Previous research on psychopathy has focused on what these individuals lack — fear, empathy and interpersonal skills. The new research, however, examines what they have in abundance — impulsivity, heightened attraction to rewards and risk taking. Importantly, it is these latter traits that are most 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 are not particularly good predictors of violence or criminal behavior,” David Zald, associate professor of psychology and of psychiatry and co-author of the study, said. “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 it overwhelms 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, imaging of the brain to measure dopamine release, in concert with a functional magnetic imaging, or fMRI, probe of the brain’s reward system.
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The researchers found in those 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.