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Just came across something that just *begged* me to discuss it in this column. It involves amygdala and motivation, so it fits in nicely with the current topic list. I promised myself when I started this blog not to get political, but this is a case in which scientific findings have been highly politicized and overinterpreted by the Press. I will present the case, the *common* interpretation that shows up in the news articles if you do a Google search on the topic, some additional scientific facts, and then how you could twist the results to support the opposite political position.
I present this not to be political, but to point out the dangers in politicizing the interpretation. Do I actually believe *either* interpretation? Actually, no, I take a more centrist view and I claim that we need to consider the results in the much broader view of total information from the field of Neuroscience.
One last warning: This blog is full of links to scientific papers. I chose those rather than the news articles to *reduce* the political spin. My apologies, but it is possible that some subscriber links will not work, but I tried to stick to public searchable papers.
A controversial study about liberal vs. conservatives and cognitive ability is a brain scan study that showed *greater* activity in some of the “cognitive processing” parts of the brain for self-identified liberal vs. conservative students (http://www.nature.com/neuro/journal/v10/n10/abs/nn1979.html).
Now there is a new study (http://www.ncbi.nlm.nih.gov/pubmed/21474316) that demonstrates that the cingulate cortex is larger in self-identified liberals, and the amygdala is larger in conservatives. The cingulate cortex is an area of the brain that deals with mismatch and conflict. When a person is presented with conflicting information and must make a decision (i.e. the “moral dilemmas” that I have talked about in this forum before), the cingulate is highly active. The amygdala is notorious for being involved in fear reaction.
Naturally, the "spin" being applied is that liberals are able to better perceive complex, conflicting information, while conservative brains are dominated by fear.
Well, there are two problems with that interpretation. First is that the amygdala is not the “fear” engine that those "spinners" would have us believe. Amygdala processes information regarding fear, true. It also processes other emotional cues.
Amygdala is a *memory* structure, as I posted in the previous blog. It is *very* important in processing expectancy of outcome with actual outcome (http://emotion.caltech.edu/dropbox/bi133/files/holland_and_gallagher.pdf). In particular it is critical for using *memory* of outcomes to guide behavior (http://neuro.cjb.net/content/23/35/11078.full). The *fear* processing is one much more highly associated with threat, than with anxiety (http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006415).
So what about cingulate? Guess what? IT DOES THE SAME THING! Cingulate responds to goal expectancy (http://neuron.nimh.nih.gov/richmond/Science.pdf). It *also* detects when the reality (reward or absence of reward) does *not* match the theoretical expectancy (http://www.jneurosci.org/content/31/11/4178.full).
Let's turn that spin around, because we can know put forth a *new* interpretation of the results. Both liberals and conservatives have different brain areas active when processing inputs. In liberals, the cingulate is more active because it is constantly having to resolve conflicts between expectancy and actuality. In conservatives, the amygdala is more active because they predict outcome based on experience and memory, and not mere reward seeking.
Sure, it’s all a matter of spin, right?
Yeah, not so much. This blog is about Science and "Getting it right!" so let’s tackle the *second* problem I mentioned. Interpreters of the 2007 brain-scan activity study failed to take into the basic foundation of neuroscience: neurons that have to work harder develop more, stronger connections and thus show more activity in a brain scan. The basis for this is a theory of plasticity, the Hebb Rule and while we know now that it is not exact, it is a good working model for brain development, cognitive function and memory formation.
Thus a different interpretation of the 2007 study is “liberal brains work harder to processing the same information as conservative brains.” This could mean anything from more effort, more experinece or more conflicts between what they expect and what actually occurs. This actually ties in with other studies which show *abnormal* behavior associated with cingulate activity such as obsessive compulsive disorder, the fact that cingulate neurons are most activated when test conditions do *not* reflect reality (http://www.sciencemag.org/content/296/5573/1709.full) and to the expectation of pain (http://www.ncbi.nlm.nih.gov/pubmed/9721952?dopt=Abstract).
So what's *really* happening here? Are conservatives vs. liberals impaired, enhanced, do they use more or less of their brains?
No. They are different. They approach problems from a different perspective. Remember, amygdala and cingulate perform very similar functions: prediction of outcomes. The *purpose* behind such a prediction has to do with planning behaviors. The brain has a number of "pre-programmed" networks to accomplish most any task that may be required. Faster reaction time and minimum "work" are provided by predicting the most likely outcome, but the brain needs to compare the prediction with the actual outcome in order to better predict in the future. The difference in roles of amygdala and cingulate is what information is involved in the prediction/comparison of outcomes. If we use a simple semantic definition of "Conservative = a person most likely to choose an action based on preserving historical trends" vs. "Liberal = a person most likely to be willing to choose an action that may involve risk and definitely involves change", then by all means, they will each use a different area of the brain: Conservative will use the area tied closest to memory - i.e. the amygdala, while Liberal will use the area associated with risk-reward and changing behavior.
Different approach, yes. Different intelligence. No. Is one *better* than the other? not necessarily, just different.
So why did I get political? Because the truth is that this is an example of the dangers of politicizing, overinterpreting or even misinterpreting science. And finally, because The Lab Rats' Guide to the Brain is all about *Getting it right*!