Volume 14 Supplement 1

Abstracts from the Twenty Second Annual Computational Neuroscience Meeting: CNS*2013

Open Access

Optimal spike pattern v.s. noise separation by neurons equipped with STDP

BMC Neuroscience201314(Suppl 1):P142

https://doi.org/10.1186/1471-2202-14-S1-P142

Published: 8 July 2013

Using numerical simulations and analytical calculations, we have recently demonstrated that, thanks to the physiological learning mechanism referred to as Spike Timing-Dependent Plasticity (STDP), neurons can detect and learn repeating spike patterns, in an unsupervised manner, even when those patterns are embedded in noise[13] - a computationally difficult problem. Here, we show that the learning rule is optimal, in that it maximizes the response to the patterns, while minimizing the mean response to noise. Therefore, by thresholding the response, one can at the same time maximize the hit rate, and minimize the false alarm rate.

More formally, if one considers a linear neuron, with n excitatory afferents, with synaptic weights w 1 ... w n in 0[1], and one input spike pattern, the goal is to find a set of synaptic weights that maximizes the neuron's response to the pattern, while minimizing the mean response to Poisson input noise. We first show that, to find the optimal set, one should convolve the input spike pattern with the excitatory postsynaptic potential (EPSP) response kernel, and select the highest resulting peaks. For each peak p, only a subset of the afferents n p contributed significantly to the response. One should select the highest peak with minimal n p , choose w = 1 for the contributing afferents, and w = 0 for all the others (in order to minimize the mean response to Poisson noise). Then, we investigate the conditions under which STDP indeed reaches this optimum, using analytical calculations with a linear inhomogeneous Poisson model[3, 4], as well as simulations with both leaky-integrate-and-fire (LIF) and Poisson neurons.

Our results indicate that, in a number of cases, STDP indeed reaches this optimum, especially when coupled with homeostatic mechanisms. In other words, when faced with one repeating pattern to learn, STDP tends to chose the best "signature" of this pattern, that is a time window with as many (nearly) coincident spikes as possible from as few afferents as possible, and concentrates weights on these afferents only, thereby minimizing the probability of strong responses due to fortuitous spike coincidences. When faced with multiple repeating patterns, the ones with best signatures tend to be learned in priority.

Declarations

Acknowledgements

This work was funded by the C.N.R.S. (T.M.) and the RIKEN Institute (M.G.). We thank Dan Goodman and Romain Brette for having developed the efficient and user-friendly Brian simulator [5], and for the quality of their support.

Authors’ Affiliations

(1)
Laboratory of Neurobiology of Adaptive Process, UMR 7102, CNRS - University Pierre et Marie Curie
(2)
Unit for Brain and Cognition, DTIC, University Pompeu Fabra

References

  1. Masquelier T, Guyonneau R, Thorpe SJ: Spike timing dependent plasticity finds the start of repeating patterns in continuous spike trains. PLoS ONE. 2008, 3: e1377-10.1371/journal.pone.0001377.PubMed CentralView ArticlePubMedGoogle Scholar
  2. Masquelier T, Guyonneau R, Thorpe SJ: Competitive STDP-Based Spike Pattern Learning. Neural Comput. 2009, 21: 1259-1276. 10.1162/neco.2008.06-08-804.View ArticlePubMedGoogle Scholar
  3. Gilson M, Masquelier T, Hugues E: STDP allows fast rate-modulated coding with Poisson-like spike trains. PLoS Comput Biol. 2011, 7: e1002231-10.1371/journal.pcbi.1002231.PubMed CentralView ArticlePubMedGoogle Scholar
  4. Kempter R, Gerstner W, Van Hemmen JL: Hebbian learning and spiking neurons. Phys Rev E. 1999, 59: 4498-4514. 10.1103/PhysRevE.59.4498.View ArticleGoogle Scholar
  5. Goodman D, Brette R: Brian: a simulator for spiking neural networks in python. Front Neuroinformatics. 2008, 2: 5-PubMed CentralView ArticleGoogle Scholar

Copyright

© Masquelier and Gilson; licensee BioMed Central Ltd. 2013

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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