Oscillatory Behavior on a Three-Node Neural Network Model with Discrete and Distributed Delays

Figure 4

Oscillatory behavior of the solutions: 𝑚𝑢=3.5, delays: (0.5, 0.6, and 0.7), and activation functions: 𝑓(𝑢)=1/(1+exp(−2𝑢)), 𝑔(𝑢)=(exp(−2𝑢)−1)/(1+exp(−2𝑢)).

(a) solid line: 𝑥₁(𝑡), dashed line: 𝑥₂(𝑡), and dotted line: 𝑥₃(𝑡)

(b) solid line: 𝑥₄(𝑡), dashed line: 𝑥₅(𝑡), and dotted line: 𝑥₆(𝑡)

(c) solid line: 𝑥₇(𝑡), dashed line: 𝑥₈(𝑡), and dotted line: 𝑥₉(𝑡)