title: Reward expectation and prediction error in human medial frontal cortex: an EEG study.
abstract: The mammalian medial frontal cortex (MFC) is involved in reward-based decision making. In particular, in nonhuman primates this area constructs expectations about upcoming rewards, given an environmental state or a choice planned by the animal. At the same time, in both humans and nonhuman primates, the MFC computes the difference between such predictions and actual environmental outcomes (reward prediction errors). However, there is a paucity of evidence about the time course of MFC-related activity during reward prediction and prediction error in humans. Here we experimentally investigated this by recording the EEG during a reinforcement learning task. Our results support the hypothesis that human MFC codes for reward prediction during the cue period and for prediction error during the outcome period. Further, reward expectation (cue period) was positively correlated with prediction error (outcome period) in error trials but negatively in correct trials, consistent with updating of reward expectation by prediction error. This demonstrates in humans, like in nonhuman primates, a role of the MFC in the rapid updating of reward expectations through prediction errors.
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000, Ghent, Belgium; GIfMI (Ghent Institute for Functional and Metabolic Imaging), Ghent University Hospital, De Pintelaan 185B, 9000 Ghent, Belgium. Electronic address: massimo.silvetti@ugent.be.
authors.forename: Massimo
authors.initials: M
authors.lastname: Silvetti
authors.forename: Elena
authors.initials: E
authors.lastname: Nuñez Castellar
authors.forename: Clémence
authors.initials: C
authors.lastname: Roger
authors.forename: Tom
authors.initials: T
authors.lastname: Verguts
mesh_terms: D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D002755:Choice Behavior / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D012054:Reinforcement, Psychology; D012201:Reward; D055815:Young Adult
keywords: ACC; Medial frontal cortex; Prediction error; Reinforcement learning; Reward