Reconciling the STDP and BCM Models of Synaptic Plasticity in a Spiking Recurrent Neural Network

Bush, Daniel, Philippides, Andrew, Husbands, Phil and O'Shea, Michael (2010) Reconciling the STDP and BCM Models of Synaptic Plasticity in a Spiking Recurrent Neural Network. Neural Computation, 22 (8). pp. 2059-2085. ISSN 0899-7667

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Abstract

Rate-coded Hebbian learning, as characterized by the BCM formulation, is an established computational model of synaptic plasticity. Recently it has been demonstrated that changes in the strength of synapses in vivo can also depend explicitly on the relative timing of pre- and postsynaptic firing. Computationalmodeling of this spike-timing-dependent plasticity (STDP) has demonstrated that it can provide inherent stability or competition based on local synaptic variables. However, it has also been demonstrated that these properties rely on synaptic weights being either depressed or unchanged by an increase in mean stochastic firing rates, which directly contradicts empirical data. Several analytical studies have addressed this apparent dichotomy and identified conditions under which distinct and disparate STDP rules can be reconciled with rate-coded Hebbian learning. The aim of this research is to verify, unify, and expand on these previous findings by manipulating each element of a standard computational STDP model in turn. This allows us to identify the conditions under which this plasticity rule can replicate experimental data obtained using both rate and temporal stimulation protocols in a spiking recurrent neural network. Our results describe how the relative scale of mean synaptic weights and their dependence on stochastic pre- or postsynaptic firing rates can be manipulated by adjusting the exact profile of the asymmetric learning window and temporal restrictions on spike pair interactions respectively. These findings imply that previously disparate models of rate-coded autoassociative learning and temporally coded heteroassociative learning, mediated by symmetric and asymmetric connections respectively, can be implemented in a single network using a single plasticity rule. However, we also demonstrate that forms of STDP that can be reconciled with rate-coded Hebbian learning do not generate inherent synaptic competition, and thus some additional mechanism is required to guarantee long-term input-output selectivity.

Item Type: Article
Schools and Departments: School of Engineering and Informatics > Informatics
Depositing User: Daniel Bush
Date Deposited: 06 Feb 2012 20:30
Last Modified: 07 Mar 2017 09:30
URI: http://sro.sussex.ac.uk/id/eprint/26294

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