Theory of excitable media

The theory of excitable media describes systems composed of interconnected units that can rapidly change their state in response to stimuli, then return to a resting state. Examples include cardiac tissue, neuron networks, and certain chemical reactions. When one unit is stimulated beyond a threshold, it activates nearby units, creating wave-like spreading activity. Afterwards, the system enters a refractory period, preventing immediate reactivation. This behavior explains phenomena like heartbeat rhythms or nerve signal transmission, where localized excitation spreads as a controllable, propagating wave, maintaining the system’s overall function while allowing for complex, dynamic patterns.