Saturday, December 08, 2007

Learning From Our Mistakes

Our ability to learn from our mistakes no doubt plays a significant role in our psychological and moral development. We all make poor decisions, and our ability to learn from those mistakes increases the likelihood that our lives will go better in the future. And this process never ends, as there are countless dimensions of our lives (e.g. relationships, career, fiscal responsibility, sport, etc.) where we have room to continue to improve and grow. So in one sense, our individual (and collective) lives are really a series of "trial and error" projects. You live and (hopefully!) you learn.

But are we *equally* apt to learn from our mistakes? A study published in the latest issue of Science suggests we are not. In "Genetically Determined Differences in Learning from Errors" the authors contend that people with a particular gene variant (A1-allele carriers) actually have difficulty learning through negative reinforcement. And this might explain why people with this particular allele have an increased risk of developing addictive behaviors.

Here is the abstract:

Genetically Determined Differences in Learning from Errors
Tilmann A. Klein et. al.

The role of dopamine in monitoring negative action outcomes and feedback-based learning was tested in a neuroimaging study in humans grouped according to the dopamine D2 receptor gene polymorphism DRD2-TAQ-IA. In a probabilistic learning task, A1-allele carriers with reduced dopamine D2 receptor densities learned to avoid actions with negative consequences less efficiently. Their posterior medial frontal cortex (pMFC), involved in feedback monitoring, responded less to negative feedback than others' did. Dynamically changing interactions between pMFC and hippocampus found to underlie feedback-based learning were reduced in A1-allele carriers. This demonstrates that learning from errors requires dopaminergic signaling. Dopamine D2 receptor reduction seems to decrease sensitivity to negative action consequences, which may explain an increased risk of developing addictive behaviors in A1-allele carriers.