Figure 17.

Effect of spontaneous excitations perturbing the time course of a successful initial condition on a square (consisting of a single triplet of "susceptible", "excited" and "refractory" states neighbors and one susceptible node. “Noise” excitations are marked by an asterisk. The first noise excitations has already been added to the initial configuration (left-hand side; turning one of the two susceptible elements into an excitation). Toward the right, each row explores one possibility of time course, partly depending on additional noise events. The numbers indicated at the end of each row are the time steps until the initial configuration is reached again.