Irreversible behavior drives neural flows in the hippocampus

TL;DR

This paper investigates how irreversibility in hippocampal neural activity relates to behavioral irreversibility, revealing that neural flows driven by animal movement can be modeled with minimal parameters, linking brain dynamics to behavior.

Contribution

It demonstrates that hippocampal irreversibility can be quantified and explained by a simple model based on animal movement parameters, connecting neural and behavioral irreversibility.

Findings

Neural irreversibility correlates with animal movement along a virtual track.

A minimal model with three parameters explains hippocampal irreversibility.

Neural flows reflect physical movement, linking brain activity to behavior.

Abstract

In the brain, neural activity undergoes directed flows between states, thus breaking time-reversal symmetry. At the same time, animals also exhibit irreversible flows between behavioral states. Yet it remains unclear whether -- and how -- irreversibility in the brain relates to irreversibility in behavior. Here, we explore this connection in the hippocampus, where neural activity encodes physical location. We show that hippocampal irreversibility can be quantified using the time-delayed cross-correlations between neurons. As a mouse moves along a virtual track, we find that physical flows through the animal's environment generate neural flows through its cognitive map. Strikingly, this neural irreversibility is explained by a minimal model with only three parameters: the average velocity of the mouse, the variance in this velocity, and the resolution of the neural encoding. Together, these results provide a mechanistic understanding of irreversibility in the hippocampus and shed light on the links between symmetry breaking in the brain and behavior.