Profile Url: honi-sanders
Researcher at Picower Institute for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology
Cells in the hippocampus tuned to spatial location (place cells) typically change their tuning when an animal changes context, a phenomenon known as remapping. A fundamental challenge to understanding remapping is the fact that what counts as a ''context change'' has never been precisely defined. Furthermore, different remapping phenomena have been classified on the basis of how much the tuning changes after different types and degrees of context change, but the relationship between these variables is not clear. We address these ambiguities by formalizing remapping in terms of hidden state inference. According to this view, remapping does not directly reflect objective, observable properties of the environment, but rather subjective beliefs about the hidden state of the environment. We show how the hidden state framework can resolve a number of puzzles about the nature of remapping.
Hippocampal place cells form a map of an animals environment. When the animal moves to a new environment, place field locations and firing rates change, a phenomenon known as remapping. Different animals can have different remapping responses to the same environments. This variability across animals in remapping behavior is not well understood. In this work, we analyzed electrophysiological recordings from Alme et al. (2014), in which five male rats were exposed to 11 different environments. To compare the hippocampal maps in two rooms, we computed average rate map correlation coefficients. We discovered that the heterogeneity in animals remapping behavior is structured: animals remapping behavior is consistent across a range of independent comparisons. Our findings highlight that remapping behavior between repeated environments depends on animal-specific factors.