title: Post-learning Hippocampal Dynamics Promote Preferential Retention of Rewarding Events.
abstract: Reward motivation is known to modulate memory encoding, and this effect depends on interactions between the substantia nigra/ventral tegmental area complex (SN/VTA) and the hippocampus. It is unknown, however, whether these interactions influence offline neural activity in the human brain that is thought to promote memory consolidation. Here we used fMRI to test the effect of reward motivation on post-learning neural dynamics and subsequent memory for objects that were learned in high- and low-reward motivation contexts. We found that post-learning increases in resting-state functional connectivity between the SN/VTA and hippocampus predicted preferential retention of objects that were learned in high-reward contexts. In addition, multivariate pattern classification revealed that hippocampal representations of high-reward contexts were preferentially reactivated during post-learning rest, and the number of hippocampal reactivations was predictive of preferential retention of items learned in high-reward contexts. These findings indicate that reward motivation alters offline post-learning dynamics between the SN/VTA and hippocampus, providing novel evidence for a potential mechanism by which reward could influence memory consolidation.
authors.affiliation: Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA. Electronic address: mjgruber@ucdavis.edu.
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: Gruber
authors.affiliation: Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA.
authors.forename: Maureen
authors.initials: M
authors.lastname: Ritchey
authors.affiliation: Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA.
authors.forename: Shao-Fang
authors.initials: SF
authors.lastname: Wang
authors.affiliation: Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Doss
authors.affiliation: Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA; Department of Psychology, University of California, Davis, Davis, CA 95618, USA.
authors.forename: Charan
authors.initials: C
authors.lastname: Ranganath
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D006624:Hippocampus / Q000098:blood supply / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D011930:Reaction Time; D012153:Retention, Psychology / Q000502:physiology*; D012201:Reward; D055815:Young Adult
chemical_list: D010100:Oxygen