Space-time approximations of the FitzHugh–Nagumo system of coupled semi-linear parabolic
PDEs are examined. The schemes under consideration are discontinuous in time but
conforming in space and of arbitrary order. Stability estimates are presented in the
natural energy norms and at arbitrary times, under minimal regularity assumptions.
Space-time error estimates of arbitrary order are derived, provided that the natural
parabolic regularity is present. Various physical parameters appearing in the model are
tracked and numerical examples are presented.