Response Maintenance by Mediated Reinforcement with Forced Alternation of Reinforcement Opportunities

Three experiments were conducted to investigate the effects of mediated reinforcement –reinforcers delivered to either of two co-actors by the responses of the other co-actor, but independently of the responses of the co-actor receiving the reinforcer– on the maintenance of responding of the co-actors. In each experiment, using a discrete-trials procedure, responding and receiving reinforcers alternated between co-actors. In Experiment 1, the alternation followed each reinforcer. Also investigated in this experiment were the effects of the presence and absence of social stimuli and of the role of reinforcement delays on individual responding. The number of consecutive reinforcer deliveries to either co-actor was fixed in Experiment 2 and varied between co-actors in Experiment 3. Under the forced alternation imposed in all three experiments, mediated reinforcement maintained responding of all co-actors. Latencies to responses were not different between mediated reinforcement and yoked-delay individual reinforcement in Experiment 1, nor did they differ as a function of the presence or absence of visual accessibility of the co-actors to one another. Of particular note was that in Experiment 3, responding was maintained even under unequal and unpredictable consecutive reinforcer deliveries. Systematic patterns of latencies to responses were observed across each pigeon under both the fixed- and variable-mediated schedules of reinforcement investigated in Experiment s 2 and 3, respectively. In those experiments, latencies to the initial response in a sequence were longest relative to subsequent latencies in a given series of successive reinforcers delivered to either co-actor. The results are interpreted as suggesting that what has been called “mediated reinforcement” may instead be the result of interacting contingencies, for example, delay of reinforcement, operating of individual co-actors