title: Dissociating contributions of ACC and vmPFC in reward prediction, outcome, and choice.
abstract: Acting in an uncertain environment requires estimating the probability and the value of potential outcomes. These computations are typically ascribed to various parts of the medial prefrontal cortex (mPFC), but the functional architecture of this region remains debated. The anterior cingulate cortex (ACC) encodes reward prediction and outcome (i.e. win vs lose, Silvetti, Seurinck, & Verguts, 2013. Cortex, 49(6), 1627-35. doi:10.1016/j.cortex.2012.05.008). An outcome-related value signal has also been reported in the ventromedial Prefrontal Cortex (vmPFC, Rangel & Hare, 2010. Current Opinion in Neurobiology, 20(2), 262-70. doi:10.1016/j.conb.2010.03.001). Whether a functional dissociation can be traced in these regions with respect to reward prediction and outcome has been suggested but not rigorously tested. Hence an fMRI study was designed to systematically examine the contribution of ACC and vmPFC to reward prediction and outcome. A striking dissociation was identified, with ACC coding for positive prediction errors and vmPFC responding to outcome, irrespective of probability. Moreover, ACC has been assigned a crucial role in the selection of intentional actions (decision-making) and computing the value associated to these actions (action-based value). Conversely, vmPFC seems to implement stimulus-based value processing (Rudebeck et al., 2008. Journal of Neuroscience, 28(51), 13775-85. doi:10.1523/JNEUROSCI.3541-08.2008; Rushworth, Behrens, Rudebeck, & Walton, 2007. Trends in Cognitive Sciences, 11(4), 168-76. doi:10.1016/j.tics.2007.01.004). Therefore, a decision-making factor (choice vs. no choice condition) was also implemented in the present paradigm to distinguish stimulus-based versus action-based value coding in the mPFC during both decision and outcome phase. We found that vmPFC was more activated during the outcome phase in the no-choice than in the choice condition, potentially confirming the role of this area in stimulus-based (more than action-based) value processing.
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, B-9000 Ghent, Belgium; GIfMI, Ghent Institute for Functional and Metabolic Imaging, Ghent University Hospital, De Pintelaan 185B, B-9000 Ghent, Belgium. Electronic address: Eliana.Vassena@UGent.be.
authors.forename: Eliana
authors.initials: E
authors.lastname: Vassena
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, B-9000 Ghent, Belgium.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Krebs
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, B-9000 Ghent, Belgium; GIfMI, Ghent Institute for Functional and Metabolic Imaging, Ghent University Hospital, De Pintelaan 185B, B-9000 Ghent, Belgium.
authors.forename: Massimo
authors.initials: M
authors.lastname: Silvetti
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, B-9000 Ghent, Belgium; GIfMI, Ghent Institute for Functional and Metabolic Imaging, Ghent University Hospital, De Pintelaan 185B, B-9000 Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Fias
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, B-9000 Ghent, Belgium; GIfMI, Ghent Institute for Functional and Metabolic Imaging, Ghent University Hospital, De Pintelaan 185B, B-9000 Ghent, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Verguts
mesh_terms: D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology*; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology*; D005260:Female; D005715:Gambling; D006179:Gyrus Cinguli / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000502:physiology*; D011336:Probability; D012201:Reward; D055815:Young Adult
keywords: ACC; Choice; Outcome; Prediction error; Value; vmPFC