title: Context-specific activation of hippocampus and SN/VTA by reward is related to enhanced long-term memory for embedded objects.
abstract: Animal studies indicate that hippocampal representations of environmental context modulate reward-related processing in the substantia nigra and ventral tegmental area (SN/VTA), a major origin of dopamine in the brain. Using functional magnetic resonance imaging (fMRI) in humans, we investigated the neural specificity of context-reward associations under conditions where the presence of perceptually similar neutral contexts imposed high demands on a putative hippocampal function, pattern separation. The design also allowed us to investigate how contextual reward enhances long-term memory for embedded neutral objects. SN/VTA activity underpinned specific context-reward associations in the face of perceptual similarity. A reward-related enhancement of long-term memory was restricted to the condition where the rewarding and the neutral contexts were perceptually similar, and in turn was linked to co-activation of the hippocampus (subfield DG/CA3) and SN/VTA. Thus, an ability of contextual reward to enhance memory for focal objects is closely linked to context-related engagement of hippocampal-SN/VTA circuitry.
authors.affiliation: Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, United Kingdom. Electronic address: e.loh@ucl.ac.uk.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Loh
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, United Kingdom.
authors.forename: Dharshan
authors.initials: D
authors.lastname: Kumaran
authors.affiliation: Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, United Kingdom; Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, United Kingdom.
authors.forename: Raphael
authors.initials: R
authors.lastname: Koster
authors.affiliation: Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, 39120 Magdeburg, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Berron
authors.affiliation: Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, United Kingdom; Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, United Kingdom; Berlin School of Mind and Brain, Humboldt University, 10099 Berlin, Germany; Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London WC1B 5EH, United Kingdom.
authors.forename: Ray
authors.initials: R
authors.lastname: Dolan
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, United Kingdom; Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, 39120 Magdeburg, Germany.
authors.forename: Emrah
authors.initials: E
authors.lastname: Duzel
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D056654:CA3 Region, Hippocampal / Q000000981:diagnostic imaging / Q000502:physiology*; D018891:Dentate Gyrus / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D057567:Memory, Long-Term / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012201:Reward; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000502:physiology*; D020651:Ventral Thalamic Nuclei / Q000000981:diagnostic imaging / Q000502:physiology*; D055815:Young Adult
keywords: Context; Dopamine; Hippocampus; Memory; Pattern-separation; Reward