“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.” [. . .]
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. [. . .]
“None of the circuits involved in conscious reasoning were particularly engaged,” Westen said. [. . .]
Notably absent were any increases in activation of the dorsolateral prefrontal cortex, the part of the brain most associated with reasoning.
Now, the interpretation put on these results, by MSNBC if not by the Emory team itself, concerns the irrationality of partisan “bias.” “Nonpartisanship” is such a strange fetish in US media and political culture.
But of course political habits are about affective fixes; and political responses are affectively conditioned before they are reasoned–or even ideological–judgements. No great surprise or scandal there.
Update: further discussion at Alas.