FACTORS CONTRIBUTING TO THE RESPONSE RATES MAINTAINED BY VARIABLE-RATIO AND VARIABLE-INTERVAL SCHEDULES OF REINFORCEMENT

In a series of four experiments, response rates maintained under multiple variable-ratio variable-interval schedules were examined using a within-subject yoke-design that equated between-component reinforcement rates. Two features proposed to control higher rates of responding during the variable-ratio schedule were independently manipulated. They were (1) the role of the reinforced interresponse time, and (2) the function relating response rate and rate of reinforcement. Collectively, the results of the four experiments point to the primacy of IRT reinforcement in shaping higher response rates under the variable-ratio schedule, thereby supporting molecular over molar accounts of response-rate effects.