Signaling delivery and non- delivery of water in temporal schedule with variations in reinforcement availability

Abstract

Twelve rats, experimentally naive at the start of the study, were used to evaluate the effects of varying the temporal availability of water delivery in a temporally defined schedule. The rats were assigned to three different experimental conditions. In a first condition, only the discriminative time period was signaled; in a second condition, only the delta time period was signaled; in the third condition, both periods were signaled. If the discriminative period was signaled, response frequency increased as the temporal availability of water deliveries decreased (excepting a phase with a minimal value of 0.3 s of availability). The overall frequency of responding in a session depended on the number of water deliveries in the first 15 cycles of this session. We discuss these results by contrasting functional differences between parameters of temporal availability and the probability of water delivery.