Genes 2 Brains 2 Mind 2 Me

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Amidst the current economic panic, I’m feeling more shocked than usual when listening to the flip-flopping, falsehoods, fabrications, backstepping, about-facing and unabashed spin-doctoring spewing forth from the news media. If watched long enough, one may even develop empathy for Henry Paulson who carries the weight of the global economy on his shoulders. Nevertheless, what do we know about making mistakes ? Not necessarily global financial catastrophies, but little everyday mistakes. Why do some of us learn from our mistakes ? What’s going on in the brain ? Enter Michael Frank, Christopher D’Lauro and Tim Curran, in their paper entitled, “Cross-task individual differences in error processing: Neural, electrophysiological and genetic components” [Cognitive, Affective, & Behavioral Neuroscience (2007), 7 (4), 297-308]. Their paper provides some amazing insight into the workings of human error-processing.

It has been known for some time that when you make a mistakke – oops! – mistake, that there are various types of electrical current that emanate from the frontal midline (cingulate cortex) of your brain.  The so-called error related negativity (ERN) occurs more strongly when you are more focused on being correct and also seems to be more strong in people with certain personality traits (apparently not news commentators or politicians) while the error positivity (Pe) occurs more strongly when you become consciously aware that you made an error (perhaps not functioning in news commentators or politicians). Perhaps the ERN and Pe are basic neural mechanisms that facilitate an organisms adaptive ability to stop and say, “hey, wait a minute, maybe I should try something new.” The Frank et al., paper describes a relation between learning and dopamine levels, and suggests that when dopamine levels dip – as happens when our expectations are violated (“oh shit!, I bought stock in Lehman Brothers“) – that this may facilitate the type of neural activity that causes us to stop and rethink things. To test whether dopamine might play a role in error processing, the team examined a common variant (rs4680) in the catechol-o-methyl transferase gene, a gene where A-carriers make a COMT enzyme that is slower to breakdown dopamine (a bulky methionine residue near the active site) than G-allele-carriers. Subjects performed a learning task where correct responses could be learned by either favoring positive feedback or avoiding negative feedback as compared to neutral stimuli. The team suspected that regardless of COMT genotype, however, there would be no COMT association with learning strategy, since COMT influences dopaminergic activity in the frontal cortex, and not in the striatum, which is the region that such reinforcement learning seems to be stored.

Interestingly, the team found that the error positivity (Pe) was higher in participants who were of the A/A genotype, but no difference in genetic groups for the error related negativity (ERN). This suggests that A/A subjects deploy more attentional focus when they realize they have made an error. Lucky folks ! My 23andMe profile shows a GG at this site, so it seems that when I make errors, I may have a normal ERN, but the subcortical dopamine that dips as a result does not (on average) result in much greater attentional focus. Oh well, I guess its the newsmedia pool for me.

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