Wavetrain response of an excitable medium to local stochastic forcing

We consider the effect of stochastic forcing on a one-dimensional excitable reaction-diffusion system, where the noise only acts on a small subdomain of the medium. We show that there are distinguished scaling limits in which the stochastic forcing gives rise to a mean response of a periodic wavetrain of pulses which are deterministic in the limit. Thus, the system responds coherently and periodically to stochastic forcing. This is an instance of self-induced stochastic resonance, which has previously only been analysed for finite-dimensional systems.