title: Learning and generalization under ambiguity: an fMRI study.
abstract: Adaptive behavior often exploits generalizations from past experience by applying them judiciously in new situations. This requires a means of quantifying the relative importance of prior experience and current information, so they can be balanced optimally. In this study, we ask whether the brain generalizes in an optimal way. Specifically, we used Bayesian learning theory and fMRI to test whether neuronal responses reflect context-sensitive changes in ambiguity or uncertainty about experience-dependent beliefs. We found that the hippocampus expresses clear ambiguity-dependent responses that are associated with an augmented rate of learning. These findings suggest candidate neuronal systems that may be involved in aberrations of generalization, such as over-confidence.
authors.affiliation: The Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom. j.chumbley@fil.ion.ucl.ac.uk
authors.forename: J R
authors.initials: JR
authors.lastname: Chumbley
authors.forename: G
authors.initials: G
authors.lastname: Flandin
authors.forename: D R
authors.initials: DR
authors.lastname: Bach
authors.forename: J
authors.initials: J
authors.lastname: Daunizeau
authors.forename: E
authors.initials: E
authors.lastname: Fehr
authors.forename: R J
authors.initials: RJ
authors.lastname: Dolan
authors.forename: K J
authors.initials: KJ
authors.lastname: Friston
mesh_terms: D000328:Adult; D001499:Bayes Theorem; D002755:Choice Behavior; D019295:Computational Biology; D005260:Female; D005793:Generalization, Psychological / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D012054:Reinforcement, Psychology; D012201:Reward