Poster Session A, Saturday, March 23, 1:30 pm - 3:30 pm, Pacific Concourse
DRD4-521T Genotypes Differentially Modulate Reward Positivity Amplitude During Reinforcement Learning
Trevor C. J. Jackson1, James F. Cavanagh1; 1University of New Mexico
The Reward Positivity (RewP) is a feedback-related ERP component that is sensitive and specific to reward surprise. As such, it is largely interpreted as a dopaminergic phenomenon. However, this association is rarely tested. Here we examined how genetic variations in dopamine sensitivity may affect the RewP, specifically pertaining to SNP DRD4-521T. This SNP can increase the amount of DRD4 receptors in the Anterior Cingulate Cortex (ACC), which in turn affects ACC functioning. Specifically, those that carry a C/C polymorphism have increased DRD4 receptors and exhibit lower ACC activation (Fan et al., 2003) as compared to their T/T polymorphism counterparts, which may in turn affect reinforcement learning, especially for those with Substance Use Disorders (Baker, et al., 2016). In the current study, participants (C/C variant, N = 25; T/T variant, N = 15) completed a probabilistic reinforcement learning task, which paired Hiragana characters with different probabilities of receiving “Correct” or “Incorrect” feedback. Those with the C/C DRD4 genotype exhibited higher RewP’s than their T/T counterparts (p = 0.015, d = 0.748). This finding was specific to increased Delta-band activity following time frequency analysis (Delta: 0.5-4 Hz, p = 0.0322). These findings suggest that DRD4 genetic variants may affect as the appraisal of reward as reflected in the RewP.
Topic Area: THINKING: Decision making