Zapping brain appears to reduce aggressive intentions, study says
The possibility of using brain stimulation to help prevent future violence just passed a proof of concept stage, according to new research published in the Journal of Neuroscience.
In a double-blind, randomized controlled study, volunteers who received a charge to their dorsolateral prefrontal cortex — the part of the brain that lies directly behind the forehead and is responsible for planning, reasoning and inhibition — were less likely to say they would consider engaging in aggressive behavior compared to a similar group that received a sham treatment.
The experiment looked at aggressive intent as well as how people reasoned about violence and found that a sense of moral wrongfulness about hypothetical acts of aggression was heightened in the group receiving the transcranial direct current stimulation (tDCS). This form of brain stimulation delivers targeted impulses to the brain through electrodes on a person’s scalp.
“Zapping offenders with an electrical current to fix their brains sounds like pulp fiction, but it might not be as crazy as it sounds,” said Adrian Raine, a neurocriminologist at the University of Pennsylvania and one of the study’s investigators.
In the experiment, 39 volunteers were given direct current stimulation to their prefrontal cortex for 20 minutes. A placebo group was given a low current for 30 seconds. On the following day, both groups read two stories, one depicting an act of physical aggression and the other an act of sexual aggression. Both groups of volunteers were then asked to rate their likelihood of performing similar acts on a scale of one to 10, with one being the least likely and 10 most likely. To gauge their sense of morality, subjects were asked to rate on a scale of zero (not at all) to 10 (very) how morally wrong it would be to act the same way as the protagonist in both stories.
For a third task measuring aggression, subjects were shown an image of a doll and told it represented a partner or friend. They were told they could relieve themselves of any negative energy toward that person by inserting zero to 51 pins into the doll. The more used, according to this metric, the greater the aggression.
The researchers found a 54 percent reduction in aggressive intentions in the group receiving the stimulation and a 31 percent jump in their sense of moral wrongfulness about acts of aggression. There was no significant difference between the two groups in the voodoo-dolllike test measuring behavioral aggression.