Delay-induced vibrational multiresonance in FitzHugh-Nagumo system

In the present paper, the phenomenon of vibrational multiresonance in a delayed FitzHugh-Nagumo system that is excited by two-frequency periodic signals is investigated. Via numerical simulation, we find that the quasiperiodic and periodic vibrational resonances in the system can be induced by the time-delay feedback, and the firing pattern of the neuron can be regulated by modulating the delay parameter. And we also find that the neuron fires just if the resonance occurs. The vibrational resonance, which is characterized by the response amplitude at the low-frequency, appears periodic in the delay parameter with two periods respectively, i.e., the period of the low-frequency signal and the one of the high-frequency signal. Further, the weak low-frequency signal in the system can be enhanced greatly by the cooperation of the high-frequency signal and the time-delay feedback. (C) 2011 Elsevier B.V. All rights reserved.