Anger in the Brain, Part II
I had a chance to catch up with Australia-based researcher Tom Denson after my earlier post, and wanted to pass along a few more observations about the neurobiology of anger that came out of that conversation.
First off, there may be something to this idea that anger is an emergent neural property that arises when the dorsal Anterior Cingulate Cortex registers a mismatch between what we expect to happen (on the basis of experience) and what actually happens. A simpler way of putting this is when reality doesn’t match prediction, we get pissed off.
As Denson explained it, “The dorsal Anterior Cingulate Cortex is a conflict detector, and not just about interpersonal social relationship conflict. It could be a conflict like the Stroop test.” (This is a well-known psychological task in which experimental subjects have to overcome a typographical conflict, as it were, and describe the color of a word, such as “red,” when it is printed in green ink). “The dACC is like a gate-keeper,” Denson said. “When you’re driving, you’re often zoned out, not really paying attention because you’ve done it so many times before. That’s based on experience. But if someone cuts you off, and there’s a mismatch between what should happen and what does happen, the dACC says, ‘Hey, there’s a problem here! Deal with it!’ That’s what’s going on in the dACC, and that’s correlated with anger.”
Just to crystallize the point, Denson added, “People in general just don’t like expectancy violation.”
That phrase—“expectancy violation”—is just another way of saying that the brain doesn’t like surprises or unexpected turns of events, which curls back to two other aspects of wisdom: the ability to deal with uncertainty and change, and emotion regulation (that is, keeping that anger under control).
Here are a couple of other interesting tidbits. As Denson and colleagues claim in their 2009 paper, researchers had not previously provoked anger in human subjects while their brains were actively being scanned; given the primacy of anger as a human emotion (and motivator), that’s remarkable. Cognitive neuroscientists have tried to approximate anger in subjects, either by showing images of angry people or asking subjects to recall an episode that made them mad. But Denson said his “primary concern is to create a realistic social environment” for his experimental subjects, and in that sense, these experiments, however preliminary, push the envelope by deliberately provoking anger in subjects while they are in the MRI machine.
Here’s another interesting observation. In the Australian anger experiments, the researchers reportedly detected no activity in the amygdala, which is one of the centers of the emotional brain. Not sure what that means, but it’s at least mildly surprising that there wasn’t at least a brief fritz of fear when the subjects were chastised.
Denson is analyzing two new data-sets that further explore the neural state of anger, with hopes of publishing in the next two or three months. It’ll be fascinating to see where this research goes.