Persistency of noise-induced spatial periodicity in excitable media

We study effects of spatiotemporal additive noise in conjunction with subthreshold travelling waves on the spatial dynamics of excitable media. We show that solely additive noise is able to extract an inherent spatial periodicity of the media in a resonant manner, thus marking the existence of spatial coherence resonance in the studied system. Next, in addition to noise, we introduce to the media excitatory waves to investigate the possibility of spatial stochastic resonance. We find that the solely noise-induced inherent spatial periodicity of the media cannot be altered by the spatial frequency of the waves. This so-called persistency of inherent spatial periodicity is attributed to the noise-robust excursion time that is characteristic for the local excitable dynamics.