The song I played at the end of day 1 is in my head at the beginning of day 2 and as the day progresses I move backward up my playlist. Has anyone else ever noticed this?

Related: Reverse replay of behavioral sequences in hippocampal place cells during the awake state (LiveScience, Nature News and Views)

Here we report that sequential replay occurs in the rat hippocampus during awake periods immediately after spatial experience. This replay has a unique form, in which recent episodes of spatial experience are replayed in a temporally reversed order. This replay is suggestive of a role in the evaluation of event sequences in the manner of reinforcement learning models. We propose that such replay might constitute a general mechanism of learning and memory.