Differential reinforcement encoding along the hippocampal long axis helps resolve the explore–exploit dilemma

Alexandre Y. Dombrovski, Beatriz Luna, Michael N. Hallquist

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


When making decisions, should one exploit known good options or explore potentially better alternatives? Exploration of spatially unstructured options depends on the neocortex, striatum, and amygdala. In natural environments, however, better options often cluster together, forming structured value distributions. The hippocampus binds reward information into allocentric cognitive maps to support navigation and foraging in such spaces. Here we report that human posterior hippocampus (PH) invigorates exploration while anterior hippocampus (AH) supports the transition to exploitation on a reinforcement learning task with a spatially structured reward function. These dynamics depend on differential reinforcement representations in the PH and AH. Whereas local reward prediction error signals are early and phasic in the PH tail, global value maximum signals are delayed and sustained in the AH body. AH compresses reinforcement information across episodes, updating the location and prominence of the value maximum and displaying goal cell-like ramping activity when navigating toward it.

Original languageEnglish (US)
Article number5407
JournalNature communications
Issue number1
StatePublished - Dec 1 2020

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General
  • General Biochemistry, Genetics and Molecular Biology
  • General Physics and Astronomy


Dive into the research topics of 'Differential reinforcement encoding along the hippocampal long axis helps resolve the explore–exploit dilemma'. Together they form a unique fingerprint.

Cite this