Associated Fokker-Planck solutions of Fitzhugh-Nagumo system with two morphogens in two spatial dimensions. Cases correspond to (left) R = - 0.04; (center) R = 0; (right) R = 0.04. All other simulation parameters D = 0.04, ϵ = 1, ρ = 0.3 are identical in all panels. The Fokker-Planck equation was solved in Comsol, until steady state (total time T = 1000) with a time step of 0.01, and zero-flux boundary conditions. The initial condition was defined as over the domain x, y ∈ [-5, 5].