Learning real-world stimuli in a neural network with spike-driven synaptic dynamics

Brader, Joseph M; Senn, Walter; Fusi, Stefano (2007). Learning real-world stimuli in a neural network with spike-driven synaptic dynamics. Neural computation, 19(11), pp. 2881-912. Cambridge, Mass.: MIT Press 10.1162/neco.2007.19.11.2881

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We present a model of spike-driven synaptic plasticity inspired by experimental observations and motivated by the desire to build an electronic hardware device that can learn to classify complex stimuli in a semisupervised fashion. During training, patterns of activity are sequentially imposed on the input neurons, and an additional instructor signal drives the output neurons toward the desired activity. The network is made of integrate-and-fire neurons with constant leak and a floor. The synapses are bistable, and they are modified by the arrival of presynaptic spikes. The sign of the change is determined by both the depolarization and the state of a variable that integrates the postsynaptic action potentials. Following the training phase, the instructor signal is removed, and the output neurons are driven purely by the activity of the input neurons weighted by the plastic synapses. In the absence of stimulation, the synapses preserve their internal state indefinitely. Memories are also very robust to the disruptive action of spontaneous activity. A network of 2000 input neurons is shown to be able to classify correctly a large number (thousands) of highly overlapping patterns (300 classes of preprocessed Latex characters, 30 patterns per class, and a subset of the NIST characters data set) and to generalize with performances that are better than or comparable to those of artificial neural networks. Finally we show that the synaptic dynamics is compatible with many of the experimental observations on the induction of long-term modifications (spike-timing-dependent plasticity and its dependence on both the postsynaptic depolarization and the frequency of pre- and postsynaptic neurons).

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Physiology
UniBE Contributor:	Senn, Walter
Subjects:	600 Technology > 610 Medicine & health
ISSN:	0899-7667
ISBN:	17883345
Publisher:	MIT Press
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:52
Last Modified:	05 Dec 2022 14:16
Publisher DOI:	10.1162/neco.2007.19.11.2881
PubMed ID:	17883345
Web of Science ID:	000249870700003
URI:	https://boris.unibe.ch/id/eprint/22270 (FactScience: 33755)