The Importance of Forgetting: Limiting Memory Improves Recovery of Topological Characteristics from Neural Data

TL;DR

This paper shows that limiting memory through synaptic transience enhances the brain's ability to accurately recover the environment's topology from hippocampal place cell activity, especially in the presence of spurious firing.

Contribution

It introduces a model where short-term plasticity improves topological data extraction from neural activity by counteracting spurious signals.

Findings

Memory limitation improves topological accuracy in neural data analysis.

Spurious firing reduces topological information unless memory is transient.

Synaptic transience acts as a mechanism to mitigate noise in neural representations.

Abstract

We develop of a line of work initiated by Curto and Itskov towards understanding the amount of information contained in the spike trains of hippocampal place cells via topology considerations. Previously, it was established that simply knowing which groups of place cells fire together in an animal's hippocampus is sufficient to extract the global topology of the animal's physical environment. We model a system where collections of place cells group and ungroup according to short-term plasticity rules. In particular, we obtain the surprising result that in experiments with spurious firing, the accuracy of the extracted topological information decreases with the persistence (beyond a certain regime) of the cell groups. This suggests that synaptic transience, or forgetting, is a mechanism by which the brain counteracts the effects of spurious place cell activity.