A Quasi-Stationary Approach to Metastability in a System of Spiking Neurons with Synaptic Plasticity

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Autori principali: Pouzat, Christophe, André, Morgan
Natura: Preprint
Pubblicazione: 2024
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author Pouzat, Christophe
André, Morgan
author_facet Pouzat, Christophe
André, Morgan
contents After reviewing the behavioral studies of working memory and of the cellular substrate of the latter, we argue that metastable states constitute candidates for the type of transient information storage required by working memory. We then present a simple neural network model made of stochastic units whose synapses exhibit short-term facilitation. The Markov process dynamics of this model was specifically designed to be analytically tractable, simple to simulate numerically and to exhibit a quasi-stationary distribution (QSD). Since the state space is finite this QSD is also a Yaglom limit, which allows us to bridge the gap between quasi-stationarity and metastability by considering the relative orders of magnitude of the relaxation and absorption times. We present first analytical results: characterization of the absorbing region of the Markov process, irreducibility outside this absorbing region and consequently existence and uniqueness of a QSD. We then apply Perron-Frobenius spectral analysis to obtain any specific QSD, and design an approximate method for the first moments of this QSD when the exact method is intractable. Finally we use these methods to study the relaxation time toward the QSD and establish numerically the memorylessness of the time of extinction.
format Preprint
id arxiv_https___arxiv_org_abs_2403_09678
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A Quasi-Stationary Approach to Metastability in a System of Spiking Neurons with Synaptic Plasticity
Pouzat, Christophe
André, Morgan
Neurons and Cognition
Probability
After reviewing the behavioral studies of working memory and of the cellular substrate of the latter, we argue that metastable states constitute candidates for the type of transient information storage required by working memory. We then present a simple neural network model made of stochastic units whose synapses exhibit short-term facilitation. The Markov process dynamics of this model was specifically designed to be analytically tractable, simple to simulate numerically and to exhibit a quasi-stationary distribution (QSD). Since the state space is finite this QSD is also a Yaglom limit, which allows us to bridge the gap between quasi-stationarity and metastability by considering the relative orders of magnitude of the relaxation and absorption times. We present first analytical results: characterization of the absorbing region of the Markov process, irreducibility outside this absorbing region and consequently existence and uniqueness of a QSD. We then apply Perron-Frobenius spectral analysis to obtain any specific QSD, and design an approximate method for the first moments of this QSD when the exact method is intractable. Finally we use these methods to study the relaxation time toward the QSD and establish numerically the memorylessness of the time of extinction.
title A Quasi-Stationary Approach to Metastability in a System of Spiking Neurons with Synaptic Plasticity
topic Neurons and Cognition
Probability
url https://arxiv.org/abs/2403.09678