Supplementary Movie 1 (fhn.mp4): Traveling Wave Evolution in the FitzHugh-Nagumo (FHN) Model

The current state is indicated by a blue marker on the dispersion curve. The pink square denotes a saddle-node bifurcation and green dot denotes a Hopf bifurcation.

As the parameter varies, the fast wave transitions through the saddle-node bifurcation into a slow wave, shrinking slightly but maintaining a largely symmetric rise and fall that appears as a scaled-down version of the fast wave. Simultaneously, the spectrum panel visualizes the linear stability dynamics, showing the fast wave losing stability as a single complex-conjugate pair of eigenvalues crosses the imaginary axis during the Hopf bifurcation.