Related Experiment Video
Updated: Apr 28, 2026

Three Laboratory Procedures for Assessing Different Manifestations of Impulsivity in Rats
Published on: March 17, 2019
The determinants of postreinforcement pausing
N K Innis1, S J Cooper, S K Mitchell
1Department of Psychology, University of Western Ontario, London, Ontario, Canada.
Abstract:
Pigeons typically pause following food presentation on schedules that program food at regular intervals. These postreinforcement pauses (prps) are a constant proportion of the interfood interval (IFI). Wynne and Staddon (1988) proposed one-back linear waiting as an account for postreinforcement pausing, or waiting time, as they called it, on response-initiated-delay schedules. Moreover, they implied that the same process could account for the prp on all fixed-interval schedules. This study examined prp performance of pigeons on two chained schedules of reinforcement, one with cyclically-changing IFIs and one in which the IFI was constant. The results provide support for the linear waiting hypothesis and replicate the findings of Innis et al. (1993) who examined performance on similar chained schedules.
Related Concept Videos
Timing and Consequences on Behavior
Humans, however, can respond to delayed reinforcers. We often make decisions between immediate small rewards and delayed larger rewards. This ability to delay gratification is a significant...
Reinforcement Schedules
Once a behavior is learned,...
Operant Conditioning
Reinforcement in operant conditioning can be positive or negative, both of which serve to increase the likelihood of a behavior. Positive...
Reinforcement
Positive reinforcement occurs when a behavior is followed by the presentation of a rewarding stimulus, increasing the frequency of that behavior. For example:
Primary and Secondary Reinforcers
Effective reinforcers for humans vary depending on the individual and the context. Primary reinforcers, such as food, water, sleep, shelter, and pleasure, have inherent value and satisfy basic biological...

