Aperiodic stochastic resonance with chaotic input signals in excitable systems

A model of two relaxation-type nonlinear oscillators is investigated. The chaotic spike sequence generated by the first system is used as a subthreshold input signal for the second system. When also exposed to noise, the latter behaves as a detector of temporal patterns in the chaotic input signal. Calculation of dynamic correlation measures shows that the information transfer between the two systems is optimized by intermediate noise levels. This behavior represents an interesting class of aperiodic stochastic resonance (ASR) with deterministic chaotic input signals. Results show that ASR is not restricted to slowly varying input signals. {copyright} {ital 1997} {ital The American Physical Society}