Poster E38, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
Interactions between oscillatory dynamics support adjustment of stimulus representations during reinforcement learning
Irene van de Vijver1,2, Joram van Driel2,3, Arjan Hillebrand4, K Richard Ridderinkhof2; 1Radboud University, 2University of Amsterdam, 3VU University, 4VU University Medical Center
Reinforcement learning (RL) in humans is subserved by a network of striatal and frontal brain areas. The electrophysiological signatures of feedback evaluation are increasingly well understood, but how those signatures relate to the use of feedback to guide subsequent behavior remains unclear. One mechanism for post-feedback behavioral optimization is the modulation of sensory processing. We used MEG and source localization to test the hypothesis that feedback induces changes in the interactions between oscillatory dynamics in the learning network and task-relevant stimulus processing areas. Participants performed a probabilistic RL task in which they learned associations between colored faces and responses by trial-and-error using feedback. Delta-band (2-4 Hz) and theta-band (4-8 Hz) power in multiple frontal regions were sensitive to feedback valence, and low and high beta-band power (12-20 and 20-30 Hz) in occipital, parietal, and temporal regions differentiated between color and face information. Crucially, single-trial power coupling in frontal-posterior networks coded an interaction between feedback valence and the relevant stimulus characteristic (color versus identity). These results suggest that long-range oscillatory coupling supports post-feedback updating of stimulus-related processing, which in turn helps enable us to optimize behavior.
Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control