Progressive‐ratio Schedules: Effects of Later Schedule Requirements on Earlier Performances

Baron, Alan; Derenne, Adam

doi:10.1901/jeab.2000.73-291

Cited by 35 publications

(21 citation statements)

References 19 publications

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“…Unlike fixed-ratio schedules, in which the response/ reinforcer ratio remains constant throughout each experimental session, progressive-ratio schedules prescribe a response/reinforcer ratio that increments progressively as a function of successive reinforcer deliveries. It is likely that responding in each ratio is influenced by the previous ratio, and possibly also by the upcoming ratio (Baron & Derenne, 2000). This could distort the relation between response rate and response/reinforcer ratio specified by Equation 1 (see below).…”

Section: Discussionmentioning

confidence: 99%

Effect of Reinforcer Magnitude on Performance Maintained by Progressive‐ratio Schedules

Rickard

Body

Zhang

et al. 2009

J Exper Analysis Behavior

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This experiment examined the relationship between reinforcer magnitude and quantitative measures of performance on progressive-ratio schedules. Fifteen rats were trained under a progressive-ratio schedule in seven phases of the experiment in which the volume of a 0.6-M sucrose solution reinforcer was varied within the range 6-300 microl. Overall response rates in successive ratios conformed to a bitonic equation derived from Killeen's (1994) Mathematical Principles of Reinforcement. The "specific activation" parameter, a, which is presumed to reflect the incentive value of the reinforcer, was a monotonically increasing function of reinforcer volume; the "response time" parameter, delta, which defines the minimum response time, increased as a function of reinforcer volume; the "currency" parameter, beta, which is presumed to reflect the coupling of responses to the reinforcer, declined as a function of volume. Running response rate (response rate calculated after exclusion of the postreinforcement pause) decayed monotonically as a function of ratio size; the index of curvature of this function increased as a function of reinforcer volume. Postreinforcement pause increased as a function of ratio size. Estimates of a derived from overall response rates and postreinforcement pauses showed a modest positive correlation across conditions and between animals. Implications of the results for the quantification of reinforcer value and for the use of progressive-ratio schedules in behavioral neuroscience are discussed.

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Section: Discussionmentioning

confidence: 99%

Effect of Reinforcer Magnitude on Performance Maintained by Progressive‐ratio Schedules

Rickard

Body

Zhang

et al. 2009

J Exper Analysis Behavior

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“…Not only does the linear one-back pause component of the model give short shrift to more distant past components, it ignores potential control by forthcoming components: Baron and Derenne (2000) have shown that schedules such as FR, extinction, and regressive ratio, postfixed to the end of a 20-component PR schedule, affect pause length and response rates on the preceding PR components.…”

Section: Experiments 5: Isolating Contextual Controlmentioning

confidence: 99%

Progressive ratio schedules of reinforcement.

Killeen¹,

Posadas-Sánchez²,

Johansen³

et al. 2009

Journal of Experimental Psychology: Animal Behavior Processes

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Pigeons' pecks produced grain under progressive ratio (PR) schedules, whose response requirements increased systematically within sessions. Experiment 1 compared arithmetic (AP) and geometric (GP) progressions. Response rates increased as a function of the component ratio requirement, then decreased linearly (AP) or asymptotically (GP). Experiment 2 found the linear decrease in AP rates to be relatively independent of step size. Experiment 3 showed pausing to be controlled by the prior component length, which predicted the differences between PR and regressive ratio schedules found in Experiment 4. When the longest component ratios were signaled by different key colors, rates at moderate ratios increased, demonstrating control by forthcoming context. Models for response rate and pause duration described performance on AP schedules; GP schedules required an additional parameter representing the contextual reinforcement. Keywordscontext; fixed ratio; mathematical model; post-reinforcement pause; progressive ratio; reinforcement schedules One of B. F. Skinner's bequests was his emphasis on the singular importance of the schedule of reinforcement, the contingencies that the experimenter or environment arranges for the presentation of events to an organism. The events could be biologically significant or insignificant, positive or negative. Nature, not Skinner, was the first to arrange reinforcement schedules, and many scientists-Pavlov and Thorndike the exemplars-used them to good effect before Skinner. But Skinner, along with his students (e.g., Ferster & Skinner, 1957) made them an end, not means, of inquiry. One of the most fundamental type of schedule arranges reinforcement contingent upon the completion of a fixed number of responses, the Fixed Ratio (FR) schedule. If the ratio is not fixed, but varies widely from one reinforcer to the next, the schedule is called Variable Ratio (VR). Ratio schedules engender high rates of responding, more or less uniform under VR, consisting of a post-reinforcement pause or break followed by a run of high rate responding under FR.It is possible to schedule ratio reinforcement intermediate between these extremes of variability. Under Progressive Ratio (PR) schedules the requirements for reinforcement are increased systematically, usually after each reinforcer. Since their introduction by Hodos (1961), PR schedules have been used increasingly to assess reinforcement strength, an assay of special importance to behavioral pharmacologists (e.g., Ping-Teng, Lee, Konz, Richardson, Correspond with: Peter Killeen, Department of Psychology, Box 871104, Arizona State University, Tempe, AZ 85287-1104, Killeen@asu.edu, FAX: (480) Voice: (480) 967-0560. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors discl...

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“…When the response requirement is low (e.g., FR 5, or 5 responses/reinforcer), responding occurs at a high, steady rate. Under a large FR schedule, the high response effort and low reinforcement rate result in erratic behavior and long pauses (Baron and Derenne, 2000; Derenne and Baron, 2002; Ferster and Skinner, 1957), a phenomenon called "ratio strain." When the ratio becomes very large responding stops altogether.…”

Section: Behavioral Effects Of Developmental Methylmercury Exposurmentioning

confidence: 99%

Methylmercury and nutrition: Adult effects of fetal exposure in experimental models

2008

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Human exposure to the life-span developmental neurotoxicant, methylmercury (MeHg), is primarily via the consumption of fish or marine mammals. Fish are also excellent sources of important nutrients, including selenium and n-3 polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA). Laboratory models of developmental MeHg exposure can be employed to assess the roles of nutrients and MeHg and to identify potential mechanisms of action if the appropriate exposure measures are used. In describing chronic exposures, relationships between daily intake and brain mercury are consistent and orderly across species, even when large differences in blood:brain ratios exist. It is well-established that low level developmental MeHg produces sensory deficits. Recent studies also show that perseveration in reversal-learning tasks occurs after gestational exposures that produce low micromolar concentrations in the brain. A no-effect level has not been identified for this effect. These exposures do not affect the acquisition or performance of discrimination learning, set shifting (extra-dimensional shift), or memory. Reversal learning deficits may be related to enhanced impact of reinforcers as measured using progressive ratio reinforcement schedules, an effect that could result in perseveration. Also reported is enhanced sensitivity to dopamine reuptake inhibitors and diminished sensitivity to pentobarbital, a GABAA agonist. Diets rich in PUFAs or selenium do not protect against MeHg's effects on reversal learning but, by themselves, may diminish variability in performance, enhance attention or psychomotor function and may confer some protection against age-related deficits in these areas. It is hypothesized that altered reward processing, dopamine and GABAergic neurotransmitter systems, and cortical regions associated with choice and perseveration are especially sensitive to developmental MeHg at low exposure levels. Human testing for MeHg's neurotoxicity should emphasize these behavioral domains.

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Progressive‐ratio Schedules: Effects of Later Schedule Requirements on Earlier Performances

Cited by 35 publications

References 19 publications

Effect of Reinforcer Magnitude on Performance Maintained by Progressive‐ratio Schedules

Effect of Reinforcer Magnitude on Performance Maintained by Progressive‐ratio Schedules

Progressive ratio schedules of reinforcement.

Methylmercury and nutrition: Adult effects of fetal exposure in experimental models

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