Research Article

Complexity Induced by External Stimulations in a Neural Network System with Time Delay

Figure 1

Intersection points of dynamic nullclines illustrate the saddle-node bifurcation of nontrivial equilibrium, where (a) one nontrivial equilibrium for and , (b) three equilibria for and , (c) one equilibrium for and , and (d) three equilibria for and , where the other parameters are , , , and .