The geometry of representational drift in natural and artificial neural networks.

Neurons in sensory areas encode/represent stimuli. Surprisingly, recent studies have suggested that, even during persistent performance, these representations are not stable and change over the course of days and weeks. We examine stimulus representations from fluorescence recordings across hundreds...

Full description

Bibliographic Details
Main Authors: Kyle Aitken, Marina Garrett, Shawn Olsen, Stefan Mihalas
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-11-01
Series:PLoS Computational Biology
Online Access:https://doi.org/10.1371/journal.pcbi.1010716
_version_ 1797974022330253312
author Kyle Aitken
Marina Garrett
Shawn Olsen
Stefan Mihalas
author_facet Kyle Aitken
Marina Garrett
Shawn Olsen
Stefan Mihalas
author_sort Kyle Aitken
collection DOAJ
description Neurons in sensory areas encode/represent stimuli. Surprisingly, recent studies have suggested that, even during persistent performance, these representations are not stable and change over the course of days and weeks. We examine stimulus representations from fluorescence recordings across hundreds of neurons in the visual cortex using in vivo two-photon calcium imaging and we corroborate previous studies finding that such representations change as experimental trials are repeated across days. This phenomenon has been termed "representational drift". In this study we geometrically characterize the properties of representational drift in the primary visual cortex of mice in two open datasets from the Allen Institute and propose a potential mechanism behind such drift. We observe representational drift both for passively presented stimuli, as well as for stimuli which are behaviorally relevant. Across experiments, the drift differs from in-session variance and most often occurs along directions that have the most in-class variance, leading to a significant turnover in the neurons used for a given representation. Interestingly, despite this significant change due to drift, linear classifiers trained to distinguish neuronal representations show little to no degradation in performance across days. The features we observe in the neural data are similar to properties of artificial neural networks where representations are updated by continual learning in the presence of dropout, i.e. a random masking of nodes/weights, but not other types of noise. Therefore, we conclude that a potential reason for the representational drift in biological networks is driven by an underlying dropout-like noise while continuously learning and that such a mechanism may be computational advantageous for the brain in the same way it is for artificial neural networks, e.g. preventing overfitting.
first_indexed 2024-04-11T04:12:23Z
format Article
id doaj.art-e8cd955d41254d4c9deafaafbb320d75
institution Directory Open Access Journal
issn 1553-734X
1553-7358
language English
last_indexed 2024-04-11T04:12:23Z
publishDate 2022-11-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Computational Biology
spelling doaj.art-e8cd955d41254d4c9deafaafbb320d752023-01-01T05:31:13ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582022-11-011811e101071610.1371/journal.pcbi.1010716The geometry of representational drift in natural and artificial neural networks.Kyle AitkenMarina GarrettShawn OlsenStefan MihalasNeurons in sensory areas encode/represent stimuli. Surprisingly, recent studies have suggested that, even during persistent performance, these representations are not stable and change over the course of days and weeks. We examine stimulus representations from fluorescence recordings across hundreds of neurons in the visual cortex using in vivo two-photon calcium imaging and we corroborate previous studies finding that such representations change as experimental trials are repeated across days. This phenomenon has been termed "representational drift". In this study we geometrically characterize the properties of representational drift in the primary visual cortex of mice in two open datasets from the Allen Institute and propose a potential mechanism behind such drift. We observe representational drift both for passively presented stimuli, as well as for stimuli which are behaviorally relevant. Across experiments, the drift differs from in-session variance and most often occurs along directions that have the most in-class variance, leading to a significant turnover in the neurons used for a given representation. Interestingly, despite this significant change due to drift, linear classifiers trained to distinguish neuronal representations show little to no degradation in performance across days. The features we observe in the neural data are similar to properties of artificial neural networks where representations are updated by continual learning in the presence of dropout, i.e. a random masking of nodes/weights, but not other types of noise. Therefore, we conclude that a potential reason for the representational drift in biological networks is driven by an underlying dropout-like noise while continuously learning and that such a mechanism may be computational advantageous for the brain in the same way it is for artificial neural networks, e.g. preventing overfitting.https://doi.org/10.1371/journal.pcbi.1010716
spellingShingle Kyle Aitken
Marina Garrett
Shawn Olsen
Stefan Mihalas
The geometry of representational drift in natural and artificial neural networks.
PLoS Computational Biology
title The geometry of representational drift in natural and artificial neural networks.
title_full The geometry of representational drift in natural and artificial neural networks.
title_fullStr The geometry of representational drift in natural and artificial neural networks.
title_full_unstemmed The geometry of representational drift in natural and artificial neural networks.
title_short The geometry of representational drift in natural and artificial neural networks.
title_sort geometry of representational drift in natural and artificial neural networks
url https://doi.org/10.1371/journal.pcbi.1010716
work_keys_str_mv AT kyleaitken thegeometryofrepresentationaldriftinnaturalandartificialneuralnetworks
AT marinagarrett thegeometryofrepresentationaldriftinnaturalandartificialneuralnetworks
AT shawnolsen thegeometryofrepresentationaldriftinnaturalandartificialneuralnetworks
AT stefanmihalas thegeometryofrepresentationaldriftinnaturalandartificialneuralnetworks
AT kyleaitken geometryofrepresentationaldriftinnaturalandartificialneuralnetworks
AT marinagarrett geometryofrepresentationaldriftinnaturalandartificialneuralnetworks
AT shawnolsen geometryofrepresentationaldriftinnaturalandartificialneuralnetworks
AT stefanmihalas geometryofrepresentationaldriftinnaturalandartificialneuralnetworks