Graded Differential Reinforcement: Response‐dependent Reinforcer Amount

Four pigeons responded under a fixed-interval 8-min schedule of food delivery in which the amount of food delivered at the end of each interval depended on performance during the interval (i.e., a correlated schedule). Specifically, duration of access to grain was contingent upon the number of responses made during the first 4 min of the interval. This differential outcome did not affect response rates or patterning relative to performance under a simple fixed-interval 8-min schedule. Behavior under the correlated schedule was then investigated under doses of cocaine ranging from 0.3 to 10.0 mg/kg. A bitonic dose-response function was obtained for response rates and the time with head in the food hopper, whereas dose-dependent decreases were observed in the mathematical index of curvature (Fry, Kelleher, & Cook, 1960). The dose that produced the greatest increase in the head-in-hopper time was then administered prior to each session. Following repeated administration of cocaine, disruptions in response patterning were attenuated for all 4 pigeons; tolerance was also observed to the rate-increasing effects and increased head-in-hopper time for 2 pigeons after chronic cocaine administration. Tolerance therefore developed despite the fact that the initial effect of cocaine was to increase the amount of food obtained.Key words: fixed-interval schedule, cocaine, tolerance, reinforcement loss, correlated schedule, key peck, pigeonsTolerance is characterized by a reduction in the potency of a drug in producing an effect after repeated administration, and can be measured in terms of changes in operant performance. Tolerance to the effects of cocaine on operant performance has been observed under several conditions of response-dependent reinforcement (e.g., Branch, Walker, & Brodkorb, 1998;Hoffman, Branch, & Sizemore, 1987;Hughes & Branch, 1991;Poling & Nickel, 1993;Schama & Branch, 1994;Smith, 1990;Stafford & Branch, 1996;van Haaren & Anderson, 1994).An influential view of how behavioral factors can influence the development of tolerance is the reinforcement-loss hypothesis (Schuster & Zimmerman, 1961), which states that tolerance is more likely to develop if deThis research was supported by USPHS Grant DA04074 from the National Institute on Drug Abuse. Data from the study provided the basis for a Masters thesis for the first author, and data from the first two phases served as a Masters thesis for the second author. We thank Brian Iwata and Tim Hackenberg for helpful comments on earlier versions of this manuscript, and Margaret Gratton, Jonathan Pinkston, and Jin Ho Yoon for assistance in experimentation.Reprints can be obtained from either the first or third author at the Department of Psychology, Box 112250, University of Florida, Gainesville, Florida 32611 (E-mail: mmiller1@ufl.edu or branch@ufl.edu).creased reinforcement rate results from the initial drug effect. For example, Schuster, Dockens, and Woods (1966) observed rats' performance on a two-component multiple schedule first under acute (once every few days) a...

Section: Effects Of Correlated Contingencies On Fi 8-min Performancecontrasting

confidence: 71%

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Tolerance to the Effects of Cocaine on Performance Under Behavior‐correlated Reinforcement Magnitude

Miller

Brodkorb

Branch

2001

“…Those relations may be conceived as correlations that vary in terms of degree (high or low) and direction (positive or negative) (Gentry & Eskew, 1984;Logan, 1960). A positive correlation between response frequency and reinforcer magnitude may be established by making larger reinforcer magnitudes dependent on either shorter interresponse times (e.g., Hendry, 1962) or a greater number of responses per interval (e.g., Gentry & Eskew, 1984). Compared to control conditions in which reinforcer magnitude is delivered independently of response frequency, the effects of both these procedures have, of course, been found to be similar: Response rates were higher under correlated conditions than under control conditions.…”

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confidence: 99%

“…Thus a very high degree of correlation can be established by increasing the magnitude by a given amount for every specified increase in response frequency (Gentry & Eskew, 1984;Hendry, 1962). These two procedures for arranging the degree of correlation between response frequency and reinforcer magnitude have not yet been compared directly.…”

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confidence: 99%

“…For this reason, comparisons of the effects of reinforcer magnitude on human responding with those of the nonhuman subjects in the Hendry (1962) and Gentry and Eskew (1984) experiments are not meaningful, and suggest the importance of investigating the effects of response-correlated increases in reinforcer magnitude on human behavior. In the present experiments we investigated the effects of specifying two degrees of positive correlation between response frequency and reinforcer magnitude on human FI performance.…”

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See 1 more Smart Citation

Some Effects of Response‐correlated Increases in Reinforcer Magnitude on Human Behavior

Buskist

Oliveira-Castro

Bennett

1988

After training under short or long fixed-interval schedules, humans responded under a modified fixedinterval schedule in which magnitude of reinforcement (X or 2X) was minimally correlated with response frequency. Response frequencies that equaled or exceeded a minimum response criterion were followed by the larger reinforcer at the end of the interval; otherwise, the smaller reinforcer was delivered. The modified schedule alternated with the baseline schedule across conditions. In a control condition, the reinforcer magnitudes produced by control subjects were yoked to those of experimental subjects. Experimental subjects, but not control subjects, showed increased responding. In addition to the baseline and modified fixed-interval schedules used in Experiment 1, subjects in Experiment 2 also responded under a second modified fixed-interval contingency in which increases in reinforcer magnitude were more highly correlated with response frequency. Experimental subjects, but not control subjects, showed increased responding under both procedures. Direct comparison of these two procedures showed that the high-correlation procedure produced greater increases in responding than did the low-correlation procedure.

Behavioral control by the response–reinforcer correlation

Kuroda

Lattal

2018

Using a discrete-trials procedure, two experiments examined the effects of response-reinforcer correlations on responding while controlling molecular variables that operated at the moment of reinforcer delivery (e.g., response-reinforcer temporal contiguity, interresponse times preceding reinforcement). Each trial consisted of three successive components: Response, Timeout, and Reinforcement, with the duration of each component held constant. The correlation between the number of responses in the Response component and reinforcer deliveries in the Reinforcement component was varied. In the Positive-correlation condition, a larger number of responses in the Response component programmed a higher reinforcement rate (Experiment 1) or a shorter time to reinforcement (Experiment 2) in the Reinforcement component. Although programmed in this way, the actual reinforcer delivery was dependent on, and occurred immediately after, a response in the Reinforcement component. In the Zero-correlation condition, the programmed rates of reinforcement (Experiment 1) or the times to reinforcement (Experiment 2) in the Reinforcement component of each trial were yoked to those in the preceding Positive-correlation condition. Responding in the Response component was higher in the Positive- than in the Zero-correlation condition, without systematic changes in molecular variables. The results suggest that the response-reinforcer correlation can be a controlling variable of behavior.