Proceedings of the Annual Meeting of the Cognitive Science Society

Hippocampal time cells carry a record of recent experience by firing during a circumscribed period of time after a triggeringstimulus. Different cells have “time fields’ at different delays up to at least tens of seconds. The observation that timefields representing events further in the past are wider supports the hypothesis that the more distant past is recorded withless resolution. However, previous studies have analyzed time fields averaged over trials, leading to the possibility thatthis could be a trial-averaging artifact. We analyzed single-unit recorded time cells with a hierarchical-Bayesian modelthat separately estimated within-trial receptive field width and across-trial variability. Even after isolating across-trialvariability, time-field width covaries with delay, consistent with less resolution for past events. Moreover, the shift oftime-fields for simultaneously recorded time cells correlates with each other, suggesting that time runs at different ratesfor the population from one trial to the next.