Concurrent schedules of reinforcement : the effects of an upper limit of reinforcement availability on changeover behavior

Pigeons partition total response output and time between both schedules of a concurrent variable-interval pair. A large amount of data has been reported which suggests that responses and time are partitioned so that they are proportional to the relative rates of reinforcement provided by concurrent variable-interval schedules. In order to obtain all programmed reinforcers, subjects must emit responses (changeover responses) which bring them into contact with each of the alternative schedules. The temporal distribution of the changeover response in the presence of each schedule has been implicated as an important factor in the matching relationship. The present study examined the relationship between changeover behavior and the occurrence of reinforcers in order to elucidate the variables affecting the temporal distribution of changeover behavior. The results demonstrated that changeover behavior occurred most frequently immediately following the point in time at which the highest frequency of reinforcement was obtained. The results are discussed in terms of the discriminative control of changeover behavior and the role of changeover behavior in concurrent schedules of reinforcement