title: Reward-Guided Learning with and without Causal Attribution.
abstract: When an organism receives a reward, it is crucial to know which of many candidate actions caused this reward. However, recent work suggests that learning is possible even when this most fundamental assumption is not met. We used novel reward-guided learning paradigms in two fMRI studies to show that humans deploy separable learning mechanisms that operate in parallel. While behavior was dominated by precise contingent learning, it also revealed hallmarks of noncontingent learning strategies. These learning mechanisms were separable behaviorally and neurally. Lateral orbitofrontal cortex supported contingent learning and reflected contingencies between outcomes and their causal choices. Amygdala responses around reward times related to statistical patterns of learning. Time-based heuristic mechanisms were related to activity in sensorimotor corticostriatal circuitry. Our data point to the existence of several learning mechanisms in the human brain, of which only one relies on applying known rules about the causal structure of the task.
authors.affiliation: Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK; Center for Behavioral Brain Sciences, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany; Faculty of Economics and Management, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany. Electronic address: jocham@ovgu.de.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Jocham
authors.affiliation: Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK; Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK. Electronic address: khbrodersen@gmail.com.
authors.forename: Kay H
authors.initials: KH
authors.lastname: Brodersen
authors.affiliation: Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.
authors.forename: Alexandra O
authors.initials: AO
authors.lastname: Constantinescu
authors.affiliation: Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.
authors.forename: Martin C
authors.initials: MC
authors.lastname: Kahn
authors.affiliation: Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK; Section on Integrative Neuroimaging, Clinical and Translational Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Intramural Research Program, Department of Health and Human Services, Bethesda, MD 20892, USA.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Ianni
authors.affiliation: Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Walton
authors.affiliation: Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK.
authors.forename: Matthew F S
authors.initials: MF
authors.lastname: Rushworth
authors.affiliation: Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK; Wellcome Trust Centre for Neuroimaging, University College London, 12 Queen Square, London WC1N 3BG, UK.
authors.forename: Timothy E J
authors.initials: TE
authors.lastname: Behrens
mesh_terms: D000328:Adult; D000679:Amygdala / Q000502:physiology*; D001921:Brain; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D002755:Choice Behavior / Q000502:physiology*; D005260:Female; D059907:Functional Neuroimaging; D000066506:Heuristics; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D009434:Neural Pathways; D017397:Prefrontal Cortex / Q000502:physiology*; D012201:Reward; D066328:Ventral Striatum / Q000502:physiology*; D055815:Young Adult