García Ojalvo, JordiSagués i Mestre, FrancescSancho, José M.Schimansky-Geier, Lutz, 1950-2011-07-072011-07-0720021539-3755https://hdl.handle.net/2445/18736We show that external fluctuations induce excitable behavior in a bistable spatially extended system with activator-inhibitor dynamics of the FitzHugh-Nagumo type. This can be understood as a mechanism for sustained signal propagation in bistable media. The phase diagram of the stochastic system is analytically obtained and numerically verified. For small-noise intensities, front propagation becomes unstable, and excitable pulses arise as the only possible spatiotemporal behavior of the system. For large-noise intensities, on the other hand, the system enters an effective regime of oscillatory behavior, where it exhibits spontaneous nucleation of pulses and synchronized firing.6 p.application/pdfeng(c) The American Physical Society, 2002Física estadísticaTermodinàmicaSistemes dinàmics diferenciablesBiofísicaFísica mèdicaBiological and medical physicsStatistical physicsThermodynamicsDifferentiable dynamical systemsBiophysicsMedical physicsinfo:eu-repo/semantics/article192337info:eu-repo/semantics/openAccess