The determinants of postreinforcement pausing.

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.