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Old 12-07-2007, 02:31 PM
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Default Dopamine D2 receptors involved in learning from mistakes

Science 7 December 2007:
Vol. 318. no. 5856, pp. 1642 - 1645
DOI: 10.1126/science.1145044
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Reports
Genetically Determined Differences in Learning from Errors
Tilmann A. Klein,1* Jane Neumann,1 Martin Reuter,2 Jürgen Hennig,3 D. Yves von Cramon,1,4 Markus Ullsperger1,4*
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.

1 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
2 University of Bonn, Bonn, Germany.
3 University of Giessen, Giessen, Germany.
4 Max Planck Institute for Neurological Research, Cologne, Germany.
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