An analysis of response and time matching to reinforcement in concurrent ratio-interval schedules

Key pecks by six pigeons were reinforced on concurrent fixed-interval fixed-ratio schedules. The value of the fixed-interval was held constant at 4 min while the fixed-ratio varied from 25 to 450 responses. All of the pigeons responded on, with pecks reinforced under, both of the schedules over most of the concurrent pairings, and four of the six distributed responses between the schedules such that matching was obtained between the proportions of responses and reinforcements. Previous studies using concurrent variable-interval schedules have shown that when response-reinforcement matching occurs, a comparable match of time to reinforcement proportions is obtained. In the present study, time devoted to each response alternative was measured from the first response on that alternative to a subsequent response on the other alternative. Using that measure, large differences existed in the local rates of responding on the two schedules, and a time-reinforcement match was not produced. These results indicate that in a situation where response-reinforcement and time-reinforcement matching are incompatible, the measurement of response proportions is the better means of evaluating the effects of reinforcement.