Changeover cost and switching between concurrent adjusting schedules

Using pigeon subjects we studied the effects of changeover cost on rates of switching between concurrent adjusting variable ratio schedules. Each side-key schedule while activated increased with the delivery of each reinforcer and decreased with reinforcer delivery when the alternate key was active. With no changeover cost, changeovers were frequent although not optimal. Switching from one side-key to the other was reduced following the addition of a single center-key changeover response, and reduced progressively further with increasing time (FI;FT), or response (FR;VR) requirements. This procedure is discussed as a model for the determination of variables which control a forager's giving-up in one food source patch and switching to another.