Date of Graduation
The independent effects of two normally confounded delays to reinforcement produced by changing between concurrent variable-interval schedules of reinforcement were examined with pigeons. In Experiments 1 and 2, combinations of changeover delays and fixed-interval travel requirements were arranged for changeovers in a changeover-key concurrent schedule procedure. The delay from a changeover-produced change in stimulus conditions to a reinforcer was varied while the delay between the last response on one alternative and a reinforcer on the other (the total obtained delay) was held constant. Changeover rates decreased as a negative power function of the total obtained delay. The delay between a changeover-produced stimulus alternation and a reinforcer had little effect on changeover rates. In Experiment 3, changeover delays and fixed-interval travel requirements were arranged independently and changeover rates decreased as a negative power function of the total obtained delay. Changeover delays and fixed-interval travel requirements resulted in similar changeover rates at similar total obtained delays. Results suggest that the effects of changeover delays and travel requirements in previous research are primarily the result of changes in the total obtained delay. Implications of these results for a reinforcement-delay based account of choice and the matching law are discussed.
Shahan, Timothy Alan, "Choice, changing over, and reinforcement delay." (1998). Graduate Theses, Dissertations, and Problem Reports. 9743.