Mechanism of bifurcation-dependent coherence resonance of excitable neuron model

Abstract

In contrast to the previous studies that have dealt with phenomenon of coherence resonance induced by external noise in excitable neuron model, in this paper the mechanism of bifurcation-dependent coherence resonance (CR) of excitable neuron model is investigated by researching the random transitions of system motion between attractors in the two sides of bifurcation point. The results of research show: For two excitable neuron model, FHN neuron model and HR neuron model, There exist different attractors in two sides of the two excitable neuron model Hopf bifurcation point, at the presence of internal or external noise the system motion may transit between attractors in two sides of bifurcation point; mechanism of bifurcation-dependent CR of excitable neuron model is related to this kind of random transitions, the frequency of transitions tend towards a certain frequency for a certain optimal noise intensity, and the signal-noise-ratio of system response evaluated at this certain frequency is maximal at the optimal noise intensity, CR occurs. © Springer-Verlag Berlin Heidelberg 2007.