Conference on Cognitive Computational Neuroscience

Replay in the brain is not a simple recapitulation of recent experience, with awake replay often unrolling in reverse temporal order upon receipt of reward, in a manner dependent on reward magnitude. These findings have led to the proposal that replay serves to update values in accordance with reinforcement learning theories. We offer a more parsimonious account of these observations, suggesting that animals associate experiences with the contexts in which they are encoded, in a manner modulated by the salience of each experience. During periods of quiescence, replay emerges when contextual cues trigger a cascade of reactivations driven by the reinstatement of each memory’s encoding context. Our theory unifies numerous replay phenomena, including findings that existing models fail to capture.