Figure 1. Attractors in Synchronous/Asynchronous Boolean Networks.

Figure 1. Diagrams of four types of attractors in Boolean networks. Attractors are outlined by slide boxes, and transient states by dashed boxes. (a) A self loop is a single state attractor. (b) A simple loop includes two or more states: each state is connected with only another state, and any two adjacent states differ from each other by only one bit. (c) A syn-complex loop is similar to simple loop, but any two adjacent states differ from each other by more than one bit. (d) A asyn-complex loop includes multiple interlinked states: each state is connected with more than one states, and there is only one bit difference between any two adjacent states. In Boolean networks, the self loop and simple loop can be identified in both synchronous Boolean networks and asynchronous Boolean networks. But the syn-complex loop only exists in the synchronous Boolean networks, and the asyn-complex loop only exists in asynchronous Boolean networks.