...Lacking a 'Guardian Angel of Behavior'
...Lacking a 'Guardian Angel of Behavior'
By Kathleen Fackelmann
In the 1991 film The Silence of the Lambs, British actor Anthony Hopkins paints an Academy Award-winning portrait of a serial killer. Now scientists are studying brain images that may help explain why real-life psychopaths display that same chilling lack of remorse.
The research, which was presented at the Society for Neuroscience meeting in San Diego, suggests that violent & abusive people probably have abnormalities in sections of the brain that are involved in making moral judgments.
The findings could raise questions about the way society deals with violent killers and other types of abusive personalities.
"Should psychopaths be punished if, for reasons beyond their control, they do not have the appropriate brain circuitry to process moral dilemmas?" asks researcher Adrian Raine of the University of Pennsylvania in Philadelphia..
Raine is among researchers who have used scanners to take snapshots of the brain. They study the images, looking for damage to regions that control rage or the ability to make a moral decision.
Small studies have suggested that a malfunction in certain brain regions might predispose people to violent, abusive & amoral behavior.
At the neuroscience meeting, Raine presented new findings from a large meta-analysis of 47 small brain-imaging studies. These smaller, inconclusive studies took brain scans of antisocial people (sociopaths & destructive narcissists), including psychopaths, as well as people without a history of violence or abuse.
After analyzing the findings on more than 1,400 people, Raine and his colleagues found that killers, antisocials and pathological people tended to have abnormalities in parts of the brain that are involved in making moral decisions, such as the prefrontal cortex.
"The prefrontal cortex is like the guardian angel of behavior," Raine says.
This region helps process emotions such as rage and the impulse to act out. "It's the part of the brain that says, 'Hey, hold on a minute.' "
The findings are the strongest to date to link brain abnormalities, particularly in the prefrontal cortex, to violent & abusive behavior, Raine says.
Preliminary findings from another brain-imaging study suggest aggressive teenage boys may have abnormalities not just in the prefrontal cortex, but also in the amygdala, a region that processes fear.
Guido Frank, a researcher at the University of Colorado-Denver, took brain scans of such young people and found that they overreact to a threat and that their prefrontal cortexes seem less able to control the urge to lash out.
Violent & abusive behavior probably is caused by a lot of factors, including exposure to abuse as a child, an impoverished environment and genetic factors, says Erik Parens, a bioethicist at the Hastings Center, a bioethics research institute in Garrison, N.Y. No one factor can explain a violent or abusive act, he says.
Even if researchers prove psychopaths and other pathological types have brain damage that predisposes them to violence, the findings might not be an excuse that will hold up in court, Raine says: "We must protect society."