Echo state networks regulated by local intrinsic plasticity rules for regression

Abstract

Intrinsic plasticity, as a biologically inspired unsupervised learning rule, is used for adapting the intrinsic excitability of the reservoir neurons. Existing intrinsic plasticity rules can only select a set of fixed rule parameters for the whole reservoir neurons, which affects the learning performance due to the lack of flexibility in providing intrinsic plasticity. In this paper, we present an echo state network (ESN) with local intrinsic plasticity rule built by different reservoir neurons which can adopt the intrinsic plasticity rule with different rule parameters to adjust its intrinsic excitability. And the covariance matrix adaptation evolution strategy is used to search and select the rule parameters corresponding to different reservoir neurons. Compared with several state-of-the-art ESN models and an ESN with the global plasticity rule, the proposed local intrinsic plasticity rule is able to achieve much better performance in some benchmark prediction tasks.