RATS' PERFORMANCE ON VARIABLE‐INTERVAL SCHEDULES WITH A LINEAR FEEDBACK LOOP BETWEEN RESPONSE RATE AND REINFORCEMENT RATE

Abstract

Three experiments investigated whether rats are sensitive to the molar properties of a variable‐interval (VI) schedule with a positive relation between response rate and reinforcement rate (i.e., a VI1 schedule). In Experiment 1, rats responded faster on a variable ratio (VR) schedule than on a VI1 schedule with an equivalent feedback function. Reinforced interresponse times (IRTs) were shorter on the VR as compared to the VI1 schedule. In Experiments 2 and 3, there was no systematic difference in response rates maintained by a VI1 schedule and a VI schedule yoked in terms of reinforcement rate. This was found both when the yoking procedure was between‐subject (Experiment 2) and within‐subject (Experiment 3). Mean reinforced IRTs were similar on both the VI1 and yoked VI schedules, but these values were more variable on the VI1 schedule. These results provided no evidence that rats are sensitive to the feedback function relating response rate to reinforcement rate on a VI1 schedule.