The hippocampus as a predictive map

Nat Neurosci. 2017 Nov;20(11):1643-1653. doi: 10.1038/nn.4650. Epub 2017 Oct 2.


A cognitive map has long been the dominant metaphor for hippocampal function, embracing the idea that place cells encode a geometric representation of space. However, evidence for predictive coding, reward sensitivity and policy dependence in place cells suggests that the representation is not purely spatial. We approach this puzzle from a reinforcement learning perspective: what kind of spatial representation is most useful for maximizing future reward? We show that the answer takes the form of a predictive representation. This representation captures many aspects of place cell responses that fall outside the traditional view of a cognitive map. Furthermore, we argue that entorhinal grid cells encode a low-dimensionality basis set for the predictive representation, useful for suppressing noise in predictions and extracting multiscale structure for hierarchical planning.

MeSH terms

  • Animals
  • Brain Mapping / methods*
  • Hippocampus / physiology*
  • Humans
  • Learning / physiology*
  • Markov Chains*
  • Mice
  • Psychomotor Performance / physiology*
  • Reinforcement, Psychology*