Do Mice Grok? Glimpses of Hidden Progress During Overtraining in Sensory Cortex

Fuente: arXiv
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Main Authors: Kumar, Tanishq, Bordelon, Blake, Pehlevan, Cengiz, Murthy, Venkatesh N., Gershman, Samuel J.
Format: Preprint
Published: 2024
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author Kumar, Tanishq
Bordelon, Blake
Pehlevan, Cengiz
Murthy, Venkatesh N.
Gershman, Samuel J.
author_facet Kumar, Tanishq
Bordelon, Blake
Pehlevan, Cengiz
Murthy, Venkatesh N.
Gershman, Samuel J.
contents Does learning of task-relevant representations stop when behavior stops changing? Motivated by recent theoretical advances in machine learning and the intuitive observation that human experts continue to learn from practice even after mastery, we hypothesize that task-specific representation learning can continue, even when behavior plateaus. In a novel reanalysis of recently published neural data, we find evidence for such learning in posterior piriform cortex of mice following continued training on a task, long after behavior saturates at near-ceiling performance ("overtraining"). This learning is marked by an increase in decoding accuracy from piriform neural populations and improved performance on held-out generalization tests. We demonstrate that class representations in cortex continue to separate during overtraining, so that examples that were incorrectly classified at the beginning of overtraining can abruptly be correctly classified later on, despite no changes in behavior during that time. We hypothesize this hidden yet rich learning takes the form of approximate margin maximization; we validate this and other predictions in the neural data, as well as build and interpret a simple synthetic model that recapitulates these phenomena. We conclude by showing how this model of late-time feature learning implies an explanation for the empirical puzzle of overtraining reversal in animal learning, where task-specific representations are more robust to particular task changes because the learned features can be reused.
format Preprint
id arxiv_https___arxiv_org_abs_2411_03541
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Do Mice Grok? Glimpses of Hidden Progress During Overtraining in Sensory Cortex
Kumar, Tanishq
Bordelon, Blake
Pehlevan, Cengiz
Murthy, Venkatesh N.
Gershman, Samuel J.
Machine Learning
Neurons and Cognition
Does learning of task-relevant representations stop when behavior stops changing? Motivated by recent theoretical advances in machine learning and the intuitive observation that human experts continue to learn from practice even after mastery, we hypothesize that task-specific representation learning can continue, even when behavior plateaus. In a novel reanalysis of recently published neural data, we find evidence for such learning in posterior piriform cortex of mice following continued training on a task, long after behavior saturates at near-ceiling performance ("overtraining"). This learning is marked by an increase in decoding accuracy from piriform neural populations and improved performance on held-out generalization tests. We demonstrate that class representations in cortex continue to separate during overtraining, so that examples that were incorrectly classified at the beginning of overtraining can abruptly be correctly classified later on, despite no changes in behavior during that time. We hypothesize this hidden yet rich learning takes the form of approximate margin maximization; we validate this and other predictions in the neural data, as well as build and interpret a simple synthetic model that recapitulates these phenomena. We conclude by showing how this model of late-time feature learning implies an explanation for the empirical puzzle of overtraining reversal in animal learning, where task-specific representations are more robust to particular task changes because the learned features can be reused.
title Do Mice Grok? Glimpses of Hidden Progress During Overtraining in Sensory Cortex
topic Machine Learning
Neurons and Cognition
url https://arxiv.org/abs/2411.03541