AVOIDANCE OF TIMEOUT FROM RESPONSE-INDEPENDENT FOOD: EFFECTS OF DELIVERY RATE AND QUALITY

In three experiments, a rat's lever presses could postpone timeouts from food pellets delivered on response‐independent schedules. In Experiment 1, the pellets were delivered at variable‐time (VT) rates ranging from VT 0.5 to VT 8 min. Experiment 2 replicated the VT 1 min and VT 8 min conditions of Experiment 1 with new subjects. Finally, subjects in Experiment 3 could postpone timeouts from delivery of pellets that differed in quality rather than quantity (unsweetened versus sweetened pellets). In general, response rates and success in avoiding increased as a function of the rate and quality of the pellets. Also, performance efficiency increased as the experiments progressed, that is, the avoidance response occurred later and later in the response‐timeout interval. The results support the conclusion that timeout from reinforcement has functional properties similar to those of more commonly studied aversive stimuli (e.g., shock).