Abstract
Some Causes of Pauses in Operant Behavior.
IVER IVERSEN (University of North Florida)

When the behavioral microscope is applied to pauses between individual instances of operant responses a myriad of seemingly chaotic activities emerge. How are these activities related to the operant behavior? Is the operant superimposed on this background of behavioral noise, is the background generated by the reinforcement schedule, or does the background influence the operant? The research attempted to cast some light on these questions. RatsÆ lever pressing was reinforced by food pellets under fixed-ratio, fixed-interval, and variable-interval schedules. Some background activities such as water drinking, wheel running, contact with the feeder area, and general exploration and grooming activities were recorded concurrently with the operant. The results revealed that under some conditions the pauses in the operant behavior are directly related to these other activities. Such relationships were demonstrated in a functional analysis where some background activities were manipulated from moment to moment. For example, the duration of access to water was varied within sessions of fixed-ratio or fixed-interval food-reinforcement schedules for lever pressing among values of 0, 10, 20, 30, 40 and 60 s. The post-reinforcement pauses in operant lever pressing were systematically related to the duration of access to water; when rats drank for a long time the pause was long and when the rats drank little or no water the pause was short. Hence, at least under these circumstances, the operant pause was caused partly by the temporal extent of the background activity. Other experiments demonstrated similar relationships. With these manipulations one can demonstrate control of individual post-reinforcement pauses to the extent that the duration of a given pause can be predicted ahead of its occurrence with an accuracy error of just a few seconds. The more general conclusion from these experiments is that the moment-to-moment pattern of operant behavior is influenced both by the reinforcement schedule and by background activities. Hence, it is possible to identify some local causes of pauses in operant behavior.