Aperiodic stochastic resonance and phase synchronization

Aperiodic stochastic resonance and phase synchronization have been considered as different phenomena in nonlinear physics which were discovered at about the same time. The former means enhancement of aperiodic signals by noise, while the latter characterizes a phase coherence in weakly coupled nonlinear oscillators. Here we show that aperiodic stochastic resonance is related to phase synchronization between the input and output signals. We introduce a measure to characterize the degree of phase synchronization and show its equivalence to a commonly used measure to quantify aperiodic stochastic resonance. (C) 2004 Elsevier B.V. All rights reserved.