Dissociable Contribution Of Prefrontal And Striatal Dopaminergic Genes To Learning In Economic Games
Set E, Saez I, Zhu L, Houser D, Myung N, Zhong SF, Ebstein R, Chew SH & Hsu M (2014) Proceedings of the National Academy of Sciences, 2014. Abstract
Game theory describes strategic interactions where success of players’ actions depends on those of coplayers. In humans, sub- stantial progress has been made at the neural level in characteriz- ing the dopaminergic and frontostriatal mechanisms mediating such behavior. Here we combined computational modeling of stra- tegic learning with a pathway approach to characterize association of strategic behavior with variations in the dopamine pathway. Specifically, using gene-set analysis, we systematically examined contribution of different dopamine genes to variation in a multi- strategy competitive game captured by (i) the degree players antic- ipate and respond to actions of others (belief learning) and (ii) the speed with which such adaptations take place (learning rate). We found that variation in genes that primarily regulate prefrontal do- pamine clearance—catechol-O-methyl transferase (COMT) and two isoforms of monoamine oxidase—modulated degree of belief learn- ing across individuals. In contrast, we did not find significant asso- ciation for other genes in the dopamine pathway. Furthermore, variation in genes that primarily regulate striatal dopamine func- tion—dopamine transporter and D2 receptors—was significantly as- sociated with the learning rate. We found that this was also the case with COMT, but not for other dopaminergic genes. Together, these findings highlight dissociable roles of frontostriatal systems in stra- tegic learning and support the notion that genetic variation, orga- nized along specific pathways, forms an important source of variation in complex phenotypes such as strategic behavior.
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