Figure 1

Excerpt from a simulation in which one of the neural networks performed the feeding task, showing the critical delay during which the network continued to egest the seaweed strip despite the inherent ingestiveness of the strip. The network received as input the stochastic ingestive or egestive stimulus stream shown at the top, and generated the ingestive or egestive behavior shown at the bottom. In this excerpt, the behavior first switched to the egestive attractor in response to a period of egestive stimulus signaling the failure to break off the strip. Thereafter the behavior remained near the egestive attractor, and egestion proceeded, even though the stimulus became ingestive. This phase of goal-driven egestion finally terminated when the behavior switched to the ingestive attractor in response to a sufficiently high local density of the ingestive stimulus (arrow at top right).