title: Hedging your bets by learning reward correlations in the human brain.
abstract: Human subjects are proficient at tracking the mean and variance of rewards and updating these via prediction errors. Here, we addressed whether humans can also learn about higher-order relationships between distinct environmental outcomes, a defining ecological feature of contexts where multiple sources of rewards are available. By manipulating the degree to which distinct outcomes are correlated, we show that subjects implemented an explicit model-based strategy to learn the associated outcome correlations and were adept in using that information to dynamically adjust their choices in a task that required a minimization of outcome variance. Importantly, the experimentally generated outcome correlations were explicitly represented neuronally in right midinsula with a learning prediction error signal expressed in rostral anterior cingulate cortex. Thus, our data show that the human brain represents higher-order correlation structures between rewards, a core adaptive ability whose immediate benefit is optimized sampling.
authors.affiliation: Wellcome Trust Center for Neuroimaging, University College London, London WC1N 3BG, UK. k.wunderlich@ucl.ac.uk
authors.forename: Klaus
authors.initials: K
authors.lastname: Wunderlich
authors.forename: Mkael
authors.initials: M
authors.lastname: Symmonds
authors.forename: Peter
authors.initials: P
authors.lastname: Bossaerts
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Dolan
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D002755:Choice Behavior; D004777:Environment; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009483:Neuropsychological Tests; D012201:Reward; D055815:Young Adult