Parametric modulation of reward sequences during a reversal task in ACC and VMPFC but not amygdala and striatum.
Several regions of the frontal cortex interact with striatal and amygdala regions to mediate the evaluation of reward-related information and subsequent adjustment of response choices. Recent theories discuss the particular relevance of dorsal anterior cingulate cortex (dACC) for switching behavior; consecutively, ventromedial prefrontal cortex (VMPFC) is involved in mediating exploitative behaviors by tracking reward values unfolding after the behavioral switch. Amygdala, on the other hand, has been implied in coding the valence of stimulus-outcome associations and the ventral striatum (VS) has consistently been shown to code a reward prediction error (RPE). Here, we used fMRI data acquired in humans during a reversal task to parametrically model different sequences of positive feedback in order to unravel differential contributions of these brain regions to the tracking and exploitation of rewards. Parameters from an Optimal Bayesian Learner accurately predicted the divergent involvement of dACC and VMPFC during feedback processing: dACC signaled the first, but not later, presentations of positive feedback, while VMPFC coded trial-by-trial accumulations in reward value. Our results confirm that dACC carries a prominent confirmatory signal during processing of first positive feedback. Amygdala coded positive feedbacks more uniformly, while striatal regions were associated with RPE.
Department of Biological and Clinical Psychology, Friedrich Schiller University, D-07743 Jena, Germany; Institute of Medical Psychology and Systems Neuroscience, University Hospital Muenster, D-48149 Muenster, Germany. Electronic address: beckermi@uni-muenster.de.
Michael P I
MP
Becker
Department of Biological and Clinical Psychology, Friedrich Schiller University, D-07743 Jena, Germany.
Alexander M
AM
Nitsch
Department of Biological and Clinical Psychology, Friedrich Schiller University, D-07743 Jena, Germany; Department of Psychology I, Julius-Maximilians-University Würzburg, D-97070 Würzburg, Germany.
Johannes
J
Hewig
Department of Biological and Clinical Psychology, Friedrich Schiller University, D-07743 Jena, Germany.
Wolfgang H R
WH
Miltner
Department of Biological and Clinical Psychology, Friedrich Schiller University, D-07743 Jena, Germany; Institute of Medical Psychology and Systems Neuroscience, University Hospital Muenster, D-48149 Muenster, Germany.
Thomas
T
Straube
D000328:Adult; D000679:Amygdala / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000502:physiology*; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D011337:Probability Learning; D012201:Reward; D055815:Young Adult
Amygdala; Midcingulate cortex; Orbitofrontal cortex; Reward; Reward sequence