Visit Indian Travel Sites
Goa,
Kerala,
Tamil Nadu,
Andhra Pradesh,
Delhi,
Rajasthan,
Uttar Pradesh,
Himachal Pradesh,
Assam,
Sikkim,
Madhya Pradesh,
Jammu & Kashmir
Karnataka
|
How the brain constructs morality | MIT neuroscientists have influenced people's moral judgments by disrupting specific brain region,
a development 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." 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
was impaired. The researchers, led by Rebecca Saxe, MIT assistant professor of
brain and cognitive sciences, report their findings in the Proceedings of the
National Academy of Sciences the week of March 29. The study offers "striking
evidence" that the right TPJ, located at the brain's surface above and behind
the right ear, is critical for making moral judgments, says Liane Young, lead
author of the paper. It's also startling, since under normal circumstances people
are very confident and consistent in these kinds of moral judgments, says Young,
a postdoctoral associate in MIT's Department of Brain and Cognitive Sciences.
"You think of morality as being a really high-level behavior," she says. "To be
able to apply (a magnetic field) to a specific brain region and change people's
moral judgments is really astonishing." To reach the conclusion, the researchers
used a non-invasive 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 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.
|
|
|
|
|
|