Context-specific activation of hippocampus and SN/VTA by reward is related to enhanced long-term memory for embedded objects

Neurobiol Learn Mem. 2016 Oct;134 Pt A(Pt A):65-77. doi: 10.1016/j.nlm.2015.11.018. Epub 2015 Dec 17.


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.

Keywords: Context; Dopamine; Hippocampus; Memory; Pattern-separation; Reward.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain Mapping / methods*
  • CA3 Region, Hippocampal / diagnostic imaging
  • CA3 Region, Hippocampal / physiology*
  • Dentate Gyrus / diagnostic imaging
  • Dentate Gyrus / physiology*
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Memory, Long-Term / physiology*
  • Pattern Recognition, Visual / physiology*
  • Reward*
  • Substantia Nigra / diagnostic imaging
  • Substantia Nigra / physiology*
  • Ventral Thalamic Nuclei / diagnostic imaging
  • Ventral Thalamic Nuclei / physiology*
  • Young Adult