Wednesday, April 7, 2010

Magnetic Field Behind Right Ear Alters Moral Judgments

Site of the day:

My magnet made me do it.

CAMBRIDGE, Mass. — MIT neuroscientists have shown they can influence people's moral judgments by disrupting a specific brain region — a finding that helps reveal how the brain constructs morality.

To make moral judgments about other people, we often need to infer their intentions — an ability known as "theory of mind." For example, if a hunter shoots his friend while on a hunting trip, we need to know what the hunter was thinking: Was he secretly jealous, or did he mistake his friend for a duck?

Previous studies have shown that a brain region known as the right temporo-parietal junction (TPJ) is highly active when we think about other people's intentions, thoughts and beliefs. In the new study, the researchers disrupted activity in the right TPJ by inducing a current in the brain using a magnetic field applied to the scalp. They found that the subjects' ability to make moral judgments that require an understanding of other people's intentions — for example, a failed murder attempt — was impaired.

Feeling all morally indignant and judgmental? Is this moral indignation wearing you out with stress and strain? Perhaps a magnet is what you need to escape from the burdens of strong feelings of morality.

Transcranial magnetic stimulation (TMS) in 500 msec bursts is enough to alter moral judgments.

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 1 (absolutely forbidden) to 7 (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 someone 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.

Could interrogators use TMS to convince, say, a captured spy that it's okay to divulge state secrets? Might nations or rogue corporations kidnap engineers and scientists and use TMS to convince them that they are morally wrong to try to hold back commercial secrets or military secrets?

Do you want to alter your own moral judgment or someone else's? If so, over what issue or behavior?

by Randall Parker


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