Noise-induced coherence in an excitable system with frequency-dependent feedback

The influence of the properties of an excitable system on the characteristics of the coherence resonance effect have been studied by experimental and numerical methods. The transition from monostable to bistable regime is accompanied by the appearance of a false maximum in the regularity parameter of the power spectrum plotted as a function of the noise intensity. An increase in the dimensionality of the system activates a mechanism whereby the noise reveals oscillatory dynamics, also resulting in the appearance of an additional maximum in the regularity parameter. (C) 2005 Pleiades Publishing, Inc.