It's really quite something. I'm pulling large sections from the more-readable blog, here, because I'm too lazy to figure out what the neurology paper is saying. The blogger writes:
Westen and his colleagues studied the brains of 15 self-identified Democrats and 15 self-identified Republicans as they were presented with a series of slides that showed undeniably inconsistent statements by John Kerry. The partisans were asked to consider whether Kerry's two statements were inconsistent, and were then asked to rate the extent to which Kerry's statements were contradictory, from 1 (strongly disagree) to 4 (strongly agree). They then repeated the process with undeniably inconsistent statements by George W. Bush, and again with inconsistent statements by politically neutral males. Here's how Westen described the results:
They had no trouble seeing the contradictions for the opposition candidate, rating his inconsistencies close to 4 on the four-point rating scale. For their own candidate, however, ratings averaged closer to 2, indicating minimal contradiction. Democrats responded to Kerry as Republicans responded to Bush. And as predicted, Democrats and Republicans showed no differences in their response to contradictions for the politically neutral figures.
The results showed that when partisans face threatening information, not only are they likely to "reason" to emotionally biased conclusions, but we can trace their neutral footprints as they do it.
When confronted with potentially troubling political information, a network of neurons becomes active that produces distress. ... The brain registers the conflict between the data and desire and begins to search for ways to turn off the spigot of unpleasant emotion. We know that the brain largely succeeded in this effort, as partisans mostly denied that they had perceived any conflict between their candidate's words and deeds.
Not only did the brain manage to shut down distress through faulty reasoning, but it did so quickly -- as best we could tell, usually before subjects even made it to the third slide [which asked them to consider whether the statements were inconsistent]. The neural circuits charged with regulation of emotional states seemed to recruit beliefs that eliminated the distress and conflict partisans had experienced when they confronted unpleasant realities. And this all seemed to happen with little involvement of the circuits normally involved in reasoning.
But the political brain also did something we didn't predict. Once partisans had found a way to reason to false conclusions, not only did neural circuits involved in negative emotions turn off, but circuits involved in positive emotions turned on. The partisan brain didn't seem satisfied in just feeling better. It worked overtime to feel good, activating reward circuits that give partisans a jolt of positive reinforcement for their biased reasoning.
This is basically the root of the well-known "confirmation bias."
Isn't that cool? The brain actually shuts down when faced with unpleasant information around your candidate. Explains a lot, doesn't it?
Partly as a result of this, and partly because I was trying to find information for myself, I have set up yet another blog, this one a temporary election season jobber, that I've called Just the facts ma'am. My hope is to answer claims by various parties and partisans with as little partisanship as I possibly can. We'll see how well I do.