Effects of Magnitude of Food Reinforcement on Free‐operant Response Rates

Abstract

In Experiment 1 rats were trained to press a lever on a variable-ratio schedule of food presentation and were then exposed to progressively increasing magnitudes of food reinforcement. Response running rates (rates exclusive of the postreinforcement pause) were found to increase as a function of increasing reinforcement magnitudes. The effect of reinforcement magnitude on response rates inclusive of the postreinforcement pause, however, was less pronounced. Increases in the magnitude of reinforcement were also found to increase the length of the postreinforcement pause. Rats in Experiment 2 were trained to respond on a chained differential-reinforcement-of-low-rate variable-ratio schedule, and were exposed to increasing magnitudes of reinforcement as in Experiment 1. Response running rates increased in the variable-ratio component but decreased in the other component of the schedule. The results are discussed with reference to incentive accounts of reinforcement and the action of reinforcement on the response units generated by the operative contingencies.

Rats don’t always respond faster for more food: The paradoxical incentive effect

“…In particular, we expected that rates would increase with increases in reinforcer amount (see, e.g., Pubols, 1960;Reed & Wright, 1988) in a manner similar to that shown in the top panel of Figure 1. The rats were exposed to a sequence of increasing VR values.…”

Parametric analysis of delayed primary and conditioned reinforcers

“…Several reinforcement parameters may influence responding, including rate, magnitude, quality, and delay (Neef, Mace, Shea, & Shade, ; Neef, Shade, & Miller, ; Pliskoff, Shull, & Gollub, ; Reed & Wright, ). Delayed reinforcement in particular has been a focus of basic research for decades and has proven to be an exceptionally influential parameter (Chung, ; Sizemore & Lattal, ).…”

Effects of Reinforcer Magnitude on Responding Under Differential‐reinforcement‐of‐low‐rate Schedules of Rats and Pigeons

“…The first attributes subcriterion IRTs to factors associated with arousal induced by reinforcer presentation and the passage of time, and the second attributes their occurrence to the degradation of reinforcer value by delay. An experimental manipulation that may differentiate between these two descriptions, and that is of interest in its own right (Beer & Trumble, 1965;Reed & Wright, 1988), is to alter reinforcer magnitude (see Bonem & Crossman, 1988, for a review). According to the first interpretation, larger reinforcer magnitudes should result in greater arousal and thus a higher frequency of responding.…”