Figure 2.

(A) The Hopf bifurcation boundary for the single, delayed self-coupled node, estimated analytically (dashed coloured lines) via a perturbation theory and numerically (solid lines, DDE-Biftool). (B) The phase portraits in the (E(t), I(t)) space for the single node for increasing values of W^E. (C) The single self-coupled node undergoes period-doubling bifurcations for sufficiently small delay, (ϵ = 0.1). (D) A period-doubling cascade is present for small delays (ϵ = 0.1, green) but not large delays (ϵ = 0.4, blue). For all simulations, the parameter values were: p = 0.2, τ₁ = 1, τ₂ = 5, W^IE = 1 and a = 5.