Political bias affects brain activity, study finds
Democrats and Republicans both adept at ignoring facts, brain scans show

Subjects were asked to evaluate statements by President George W. Bush
and Democratic presidential nominee Sen. John Kerry, seen here after a
debate on Oct. 8, 2004. Both Republicans and Democrats ignored
information that could not rationally be discounted, the study found.

Updated: 6:46 p.m. ET Jan. 24, 2006

Democrats and Republicans alike are adept at making decisions without
letting the facts get in the way, a new study shows.

And they get quite a rush from ignoring information that's contrary to
their point of view.

Researchers asked staunch party members from both sides to evaluate
information that threatened their preferred candidate prior to the 2004
Presidential election. The subjects' brains were monitored while they
pondered.
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The results were announced today.

"We did not see any increased activation of the parts of the brain
normally engaged during reasoning," said Drew Westen, director of
clinical psychology at Emory University. "What we saw instead was a
network of emotion circuits lighting up, including circuits
hypothesized to be involved in regulating emotion, and circuits known
to be involved in resolving conflicts."

Bias on both sides
The test subjects on both sides of the political aisle reached totally
biased conclusions by ignoring information that could not rationally be
discounted, Westen and his colleagues say.

Then, with their minds made up, brain activity ceased in the areas that
deal with negative emotions such as disgust. But activity spiked in the
circuits involved in reward, a response similar to what addicts
experience when they get a fix, Westen explained.

The study points to a total lack of reason in political decision-making.

"None of the circuits involved in conscious reasoning were particularly
engaged," Westen said. "Essentially, it appears as if partisans twirl
the cognitive kaleidoscope until they get the conclusions they want,
and then they get massively reinforced for it, with the elimination of
negative emotional states and activation of positive ones."

Notably absent were any increases in activation of the dorsolateral
prefrontal cortex, the part of the brain most associated with
reasoning.

The tests involved pairs of statements by the candidates, President
George W. Bush and Senator John Kerry, that clearly contradicted each
other. The test subjects were asked to consider and rate the
discrepancy. Then they were presented with another statement that might
explain away the contradiction. The scenario was repeated several times
for each candidate.

A brain-scan technique known as functional magnetic resonance imaging,
or fMRI, revealed a consistent pattern. Both Republicans and Democrats
consistently denied obvious contradictions for their own candidate but
detected contradictions in the opposing candidate.

"The result is that partisan beliefs are calcified, and the person can
learn very little from new data," Westen said.

Other relatively neutral candidates were introduced into the mix, such
as the actor Tom Hanks. Importantly, both the Democrats and Republicans
reacted to the contradictions of these characters in the same manner.

The findings could prove useful beyond the campaign trail.

"Everyone from executives and judges to scientists and politicians may
reason to emotionally biased judgments when they have a vested interest
in how to interpret 'the facts,'" Westen said.

The researchers will present the findings Saturday at the Annual
Conference of the Society for
Personality and Social Psychology.


FACT FILE Brain scanners
INTRO
Functional brain imaging helps scientists understand the relationship
between particular types of mental activity and particular areas of the
brain, by charting which regions experience increased blood flow or
metabolism or electromagnetic activity over time. It’s a step beyond CT
scans, or CAT scans, which can map the brain’s structure but not its
functions. Click on the labels above to learn more about three
technologies used for functional brain imaging.
Source: University of Washington, Macalester College, Encarta


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