Wave Pattern Selection in an Excitable System

Wave pattern selection between periodic spirals and periodic circular pacemaker waves in excitable media is investigated with numerical simulations in a FitzHugh-Nagumo reaction-diffusion model. When spirals have oscillatory tails circular waves are more likely dominant over spirals, whereas it is opposite when spirals have monotonic tails. In both cases a coherent state is achieved in an asymptotic limit with a single period and a velocity. The observed wave pattern selection mechanism seems to underlie the competition between spirals and circular waves observed in signaling activity of Dictyostelium discoideum amoebae population.