Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence Detection

Repeating spatiotemporal spike patterns exist and carry information. Here we investigated how a single spiking neuron can optimally respond to one given pattern (localist coding), or to either one of several patterns (distributed coding, i.e., the neuron's response is ambiguous but the identity...

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Main Authors: Timothée Masquelier, Saeed R. Kheradpisheh
Format: Article
Language:English
Published: Frontiers Media S.A. 2018-09-01
Series:Frontiers in Computational Neuroscience
Subjects:
Online Access:https://www.frontiersin.org/article/10.3389/fncom.2018.00074/full
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author Timothée Masquelier
Timothée Masquelier
Saeed R. Kheradpisheh
author_facet Timothée Masquelier
Timothée Masquelier
Saeed R. Kheradpisheh
author_sort Timothée Masquelier
collection DOAJ
description Repeating spatiotemporal spike patterns exist and carry information. Here we investigated how a single spiking neuron can optimally respond to one given pattern (localist coding), or to either one of several patterns (distributed coding, i.e., the neuron's response is ambiguous but the identity of the pattern could be inferred from the response of multiple neurons), but not to random inputs. To do so, we extended a theory developed in a previous paper (Masquelier, 2017), which was limited to localist coding. More specifically, we computed analytically the signal-to-noise ratio (SNR) of a multi-pattern-detector neuron, using a threshold-free leaky integrate-and-fire (LIF) neuron model with non-plastic unitary synapses and homogeneous Poisson inputs. Surprisingly, when increasing the number of patterns, the SNR decreases slowly, and remains acceptable for several tens of independent patterns. In addition, we investigated whether spike-timing-dependent plasticity (STDP) could enable a neuron to reach the theoretical optimal SNR. To this aim, we simulated a LIF equipped with STDP, and repeatedly exposed it to multiple input spike patterns, embedded in equally dense Poisson spike trains. The LIF progressively became selective to every repeating pattern with no supervision, and stopped discharging during the Poisson spike trains. Furthermore, tuning certain STDP parameters, the resulting pattern detectors were optimal. Tens of independent patterns could be learned by a single neuron using a low adaptive threshold, in contrast with previous studies, in which higher thresholds led to localist coding only. Taken together these results suggest that coincidence detection and STDP are powerful mechanisms, fully compatible with distributed coding. Yet we acknowledge that our theory is limited to single neurons, and thus also applies to feed-forward networks, but not to recurrent ones.
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spelling doaj.art-54ff0e88b0a541379047dfbdc5066d1b2022-12-21T19:03:16ZengFrontiers Media S.A.Frontiers in Computational Neuroscience1662-51882018-09-011210.3389/fncom.2018.00074410212Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence DetectionTimothée Masquelier0Timothée Masquelier1Saeed R. Kheradpisheh2Centre de Recherche Cerveau et Cognition, UMR5549 CNRS—Université Toulouse 3, Toulouse, FranceInstituto de Microelectrónica de Sevilla (IMSE-CNM), CSIC, Universidad de Sevilla, Sevilla, SpainDepartment of Computer Science, Faculty of Mathematical Sciences and Computer, Kharazmi University, Tehran, IranRepeating spatiotemporal spike patterns exist and carry information. Here we investigated how a single spiking neuron can optimally respond to one given pattern (localist coding), or to either one of several patterns (distributed coding, i.e., the neuron's response is ambiguous but the identity of the pattern could be inferred from the response of multiple neurons), but not to random inputs. To do so, we extended a theory developed in a previous paper (Masquelier, 2017), which was limited to localist coding. More specifically, we computed analytically the signal-to-noise ratio (SNR) of a multi-pattern-detector neuron, using a threshold-free leaky integrate-and-fire (LIF) neuron model with non-plastic unitary synapses and homogeneous Poisson inputs. Surprisingly, when increasing the number of patterns, the SNR decreases slowly, and remains acceptable for several tens of independent patterns. In addition, we investigated whether spike-timing-dependent plasticity (STDP) could enable a neuron to reach the theoretical optimal SNR. To this aim, we simulated a LIF equipped with STDP, and repeatedly exposed it to multiple input spike patterns, embedded in equally dense Poisson spike trains. The LIF progressively became selective to every repeating pattern with no supervision, and stopped discharging during the Poisson spike trains. Furthermore, tuning certain STDP parameters, the resulting pattern detectors were optimal. Tens of independent patterns could be learned by a single neuron using a low adaptive threshold, in contrast with previous studies, in which higher thresholds led to localist coding only. Taken together these results suggest that coincidence detection and STDP are powerful mechanisms, fully compatible with distributed coding. Yet we acknowledge that our theory is limited to single neurons, and thus also applies to feed-forward networks, but not to recurrent ones.https://www.frontiersin.org/article/10.3389/fncom.2018.00074/fullneural codinglocalist codingdistributed codingcoincidence detectionleaky integrate-and-fire neuronspatiotemporal spike pattern
spellingShingle Timothée Masquelier
Timothée Masquelier
Saeed R. Kheradpisheh
Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence Detection
Frontiers in Computational Neuroscience
neural coding
localist coding
distributed coding
coincidence detection
leaky integrate-and-fire neuron
spatiotemporal spike pattern
title Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence Detection
title_full Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence Detection
title_fullStr Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence Detection
title_full_unstemmed Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence Detection
title_short Optimal Localist and Distributed Coding of Spatiotemporal Spike Patterns Through STDP and Coincidence Detection
title_sort optimal localist and distributed coding of spatiotemporal spike patterns through stdp and coincidence detection
topic neural coding
localist coding
distributed coding
coincidence detection
leaky integrate-and-fire neuron
spatiotemporal spike pattern
url https://www.frontiersin.org/article/10.3389/fncom.2018.00074/full
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