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Main Authors: Martín-Cornejo, Paulina R., Boyer, Denis
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2509.01806
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author Martín-Cornejo, Paulina R.
Boyer, Denis
author_facet Martín-Cornejo, Paulina R.
Boyer, Denis
contents Random walks on lattices with preferential relocation to previously visited sites provide a simple framework for modeling the displacements of animals and humans. When the lattice contains a few impurities or resource sites where the walker spends more time on average at each visit than on the other sites, the long range memory can suppress diffusion and induce by reinforcement a steady state localized around a resource. This phenomenon can be identified with a spatial learning process. Here we study theoretically and numerically how the decay of memory impacts learning in a model with one impurity. If memory decays as $1/τ$ or slower, where $τ$ is the time backward into the past, the localized solution is the same as with perfect, non-decaying memory and it is linearly stable. If forgetting is faster than $1/τ$, for instance exponential, an unusual regime of intermittent localization is observed, where well localized periods of exponentially distributed duration are disrupted by possibly long intervals of diffusive motion. At the transition between the two regimes, for a kernel in $1/τ$, the approach to the stable localized state is the fastest, opposite to the expected critical slowing down effect. Hence, forgetting can allow the walker to save a lot of memory without compromising learning and to achieve a faster learning process. These findings agree with biological evidence on the benefits of forgetting.
format Preprint
id arxiv_https___arxiv_org_abs_2509_01806
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Intermittent localization and fast spatial learning by non-Markov random walks with decaying memory
Martín-Cornejo, Paulina R.
Boyer, Denis
Statistical Mechanics
Neurons and Cognition
Random walks on lattices with preferential relocation to previously visited sites provide a simple framework for modeling the displacements of animals and humans. When the lattice contains a few impurities or resource sites where the walker spends more time on average at each visit than on the other sites, the long range memory can suppress diffusion and induce by reinforcement a steady state localized around a resource. This phenomenon can be identified with a spatial learning process. Here we study theoretically and numerically how the decay of memory impacts learning in a model with one impurity. If memory decays as $1/τ$ or slower, where $τ$ is the time backward into the past, the localized solution is the same as with perfect, non-decaying memory and it is linearly stable. If forgetting is faster than $1/τ$, for instance exponential, an unusual regime of intermittent localization is observed, where well localized periods of exponentially distributed duration are disrupted by possibly long intervals of diffusive motion. At the transition between the two regimes, for a kernel in $1/τ$, the approach to the stable localized state is the fastest, opposite to the expected critical slowing down effect. Hence, forgetting can allow the walker to save a lot of memory without compromising learning and to achieve a faster learning process. These findings agree with biological evidence on the benefits of forgetting.
title Intermittent localization and fast spatial learning by non-Markov random walks with decaying memory
topic Statistical Mechanics
Neurons and Cognition
url https://arxiv.org/abs/2509.01806