Fig. 3.

Behavior of a single relaxation oscillator. (a) Enabled oscillator. An enabled oscillator produces a stable periodic orbit shown in bold with the direction of movement indicated by the arrows. The periodic solution alternates between an active phase of relatively high values of x, and a silent phase of relatively low values of x, and the jumps between the two phases are indicated by double arrows. (b) Excitable oscillator. In this state, the oscillator produces a stable fixed point at a low value of x. (c) Temporal activity of an enabled oscillator. The curve shows the x activity of the oscillator