FitzHugh-Nagumo — Excitable Waves
2D reaction-diffusion · spiral waves · target patterns
Parameters
ε (excit.)
0.10
a (threshold)
0.75
b (recovery)
0.02
Du (activator)
1.0
Dv (inhibitor)
0.0
Speed
3
Stimulate
Pulse (center)
Spiral seed
Random seeds
Reset
About
FitzHugh-Nagumo is a simplified neuron model showing excitable dynamics:
∂u/∂t = Du∇²u + u(1−u)(u−a) − v
∂v/∂t = Dv∇²v + ε(u − bv)
u is the activator (fast, voltage-like), v is the recovery variable (slow). Waves propagate without decay — similar to cardiac tissue. Spirals form from broken wavefronts.