Research scientists at MIT have been studying the right temporo-parietal junction (TPJ) region of the brain that seems to be involved in judging the behavior of other people. With the help of transcranial magnetic stimulation (TMS) applied to the region, they were able to affect the moral conclusions that people reached when analyzing the actions of others.
From MIT news office:
The researchers used a noninvasive technique known as transcranial magnetic stimulation (TMS) to selectively interfere with brain activity in the right TPJ. A magnetic field applied to a small area of the skull creates weak electric currents that impede nearby brain cells’ ability to fire normally, but the effect is only temporary.
In one experiment, volunteers were exposed to TMS for 25 minutes before taking a test in which they read a series of scenarios and made moral judgments of characters’ actions on a scale of one (absolutely forbidden) to seven (absolutely permissible).
In a second experiment, TMS was applied in 500-milisecond bursts at the moment when the subject was asked to make a moral judgment. For example, subjects were asked to judge how permissible it is for a man to let his girlfriend walk across a bridge he knows to be unsafe, even if she ends up making it across safely. In such cases, a judgment based solely on the outcome would hold the perpetrator morally blameless, even though it appears he intended to do harm.
In both experiments, the researchers found that when the right TPJ was disrupted, subjects were more likely to judge failed attempts to harm as morally permissible. Therefore, the researchers believe that TMS interfered with subjects’ ability to interpret others’ intentions, forcing them to rely more on outcome information to make their judgments.
Image: MRI brain scans showing the location of the right temporoparietal junction (blue circle). The purple triangle shows a nearby region that the researchers disrupted with magnetic stimulation as a control experiment.
Press release: Moral judgments can be altered … by magnets
Abstract in PNAS: Disruption of the right temporoparietal junction with transcranial magnetic stimulation reduces the role of beliefs in moral judgments
