Coherence Resonance in a Noise-Driven Excitable System

TLDR

Noise activates the system producing a sequence of pulses. We study the dynamics of the excitable Fitz Hugh–Nagumo system under external noisy driving. This new effect of coherence resonance is explained by different noise dependencies of the activation and the excursion times, and a simple one-dimensional Langevin model is proposed for quantitative description. The coherence of these noise‑induced oscillations is shown to be maximal for a certain noise amplitude.

Abstract

We study the dynamics of the excitable Fitz Hugh--Nagumo system under external noisy driving. Noise activates the system producing a sequence of pulses. The coherence of these noise-induced oscillations is shown to be maximal for a certain noise amplitude. This new effect of coherence resonance is explained by different noise dependencies of the activation and the excursion times. A simple one-dimensional model based on the Langevin dynamics is proposed for the quantitative description of this phenomenon.