Abstract
The variability in the behavioral equilibrium established by six basic schedules was characterized. The measures were the pause preceding the first response in each interreinforcement interval; the mean rate of responding in each interreinforcement interval; and the relative frequency of each interresponse time. The temporal windows ranged across the 780-session exposure, across a session, and across the interreinforcement interval. A display of individual interresponse times as a function of time in the interreinforcement interval indicated clear recurrent responding at somewhat less than 3 Hz in every bird, even after extended exposure to a schedule and regardless of the contingency. No strong sequential dependencies in the interresponse-time distributions were identified. A simulator, based on a simple recurrent pulser, was presented that produced output similar to the obtained data. An archival data base of the behavior chronically maintained by the simple schedules was also generated.