Abstract
Three Japanease monkeys (Macaca fuscata) performed on three types of schedules : (a) a delay-dependent schedule where interreinforcement interval was held constant (i.e., increases in pause time decreased food delay), (b) an interreinforcement-interval-dependent schedule where food delay was held constant (i.e., increases in pause time increased interreinforcement interval), and (c) a both-dependent schedule where increases in pause time produced increases in interreinforcement interval but decreases in food delay. Pause times were typically shorter under the delay-dependent schedule than under the both-dependent sched-ule. Whereas pause time under the interreinforcement-interval-dependent schedule for I subject was similar to that under both-dependent schedule. The other subjects pause times under the interreinforcement-interval-dependent schedule were longer than that under the both-dependent schedule. The present results in monkeys confirmed the pigeons' results that neither the interreinforcement interval nor food delay is the primary variable controlling pause time, but rather that the two interact in a complex manner to determine the pause time.
