SEARCH · PubMed Health

Results for “Reinforcement Schedule”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources

PubMed1995

Effects of neuropeptide Y, insulin, 2-deoxyglucose, and food deprivation on food-motivated behavior.

The current study demonstrates the ability of neuropeptide Y (NPY) to increase break points under a progressive ratio 1 (PR1) reinforcement schedule. An initial response resulted in delivery of a food reinforcer (45 mg pellet) under the PR1, and an additional response was required for each successive reinforcer. The break point, the number of responses emitted to obtain the last reinforcer, is considered a measure of reinforcing efficacy or motivational strength of the food reinforcer. NPY (0.3-10 micrograms) significantly increased break point to levels comparable to those produced by 36-48 h of food deprivation. Although insulin (3-8 U/kg) and 2-deoxyglucose (150-250 mg/kg) also increased food intake, neither increased break points to levels produced by NPY or food deprivation. These data suggest that NPY may change the value of food in ways that cannot be accounted for by changes in insulin, glucose levels or intracellular glucoprivation. These results emphasize that simply measuring the amount of freely available food eaten is not a fully adequate measure of the strength of the feeding behavior.

Animals↗

PubMed1993

Effects of sex steroids on maternal motivation in the common marmoset (Callithrix jacchus): development and application of an operant system with maternal reinforcement.

We developed an operant paradigm for measuring effects of reproductive steroids on maternal motivation in common marmosets (Callithrix jacchus). Conditioned response regulated females' exposure to maternal reinforcement. Nulliparous females (n = 15) with experience with infants in social groups were subjects. The paradigm was validated by examining (a) effects of reinforcing stimuli on affective behavior in a nonoperant paradigm, (b) responsiveness of operant performance to changes in reinforcing stimuli and reinforcement schedule, (c) changes in operant responding due to omission of reinforcement, and (d) relation between operant responding and species-typical maternal behavior. In pregnant females, (n = 4), frequency of bar pressing and estradiol:progesterone ratio were maximal just before birth. Nonpregnant females (n = 3) treated with progesterone and estradiol to mimic late-pregnancy steroid profiles showed increased operant maternal behavior.

Acoustic Stimulation↗

PubMed2001

Evaluating the predictive validity of a single stimulus engagement preference assessment.

Most preference assessments require individuals to choose among two or more stimuli. More recently, the duration of engagement with items has been used as an index of preference. In the current study, the predictive validity of a single stimulus engagement (SSE) preference assessment was evaluated with 4 individuals. Stimuli were presented singly for a brief period while engagement with that stimulus was recorded. Although SSE preference rankings closely matched paired stimulus preference assessment rankings for only 2 of the 4 participants, relative preference rankings based on duration of engagement predicted relative reinforcer effectiveness for all participants in a subsequent concurrent-schedule reinforcer assessment. The SSE procedure took less time to administer than the paired stimulus procedure but produced less stable preference rankings across administrations. The SSE procedure may be appropriate for individuals who have difficulty selecting one stimulus from among two or more stimuli, and it may be well suited for evaluating activities that are difficult to present in a paired stimulus format.

Adolescent↗

PubMed2000

Second-order schedules of drug reinforcement in rats and monkeys: measurement of reinforcing efficacy and drug-seeking behaviour.

RATIONALE AND OBJECTIVES: To review the literature on the use of second-order schedules of drug reinforcement in the context of experimental investigations of the neural and pharmacological mechanisms underlying addictive behaviour in general and drug-seeking behaviour in particular. METHODS: Second-order schedules of drug reinforcement are described in which responding is maintained not only by the self-administered drug, but also by contingent presentation of drug-paired stimuli that serve as conditioned reinforcers of instrumental behaviour. RESULTS: The behaviour of rats and monkeys responding under second-order schedules is discussed in relation to self-administered drug dose and the importance of drug-associated cues in maintaining responding for cocaine, morphine or heroin. Drug-seeking behaviour during the period before drug is self-administered is described and compared with drug-seeking behaviour derived from other procedures. In addition, results are summarised that demonstrate the differential involvement of the amygdala and prefrontal cortex in the acquisition of cue-controlled cocaine- and heroin-seeking behaviour, as well as the effects of drugs interacting with D3 dopamine, NMDA and AMPA receptors on drug-seeking behaviour and dopaminergic correlates of drug-paired stimuli presented non-contingently and during responding for cocaine under a second-order schedule. CONCLUSIONS: We argue that the first, drug-free interval (or other period) of responding under a second-order schedule of reinforcement has particular utility in that it provides a measure of drug-seeking behaviour and reinforcing efficacy that are not affected by the pharmacological effects of recently administered drug. It also provides a means of investigating the role of drug-paired stimuli in drug-seeking behaviour, including its behavioural, neural and neurochemical basis.

Animals↗

PubMed1975

Classical skin conductance response conditioning: effects of intermittent reinforcement and information about schedule contingencies.

Skin conductance responses were differentially conditioned using reinforcement schedules of 25%, 50%, 75%, and 100%, manipulated between subjects. Half of the subjects were informed about schedule contingencies, and half were uninformed. The interstimulus interval was 6 sec. Discrimination of first-interval responses (1.0-3.5 sec after conditioned stimulus [CS] onset) by informed subjects did not vary with the ratio variable, but that by uninformed subjects improved with increasing reinforcement ratio because of diminished response levels to the nonreinforced CS (CS-). Discrimination of second-interval responses (3.6-7.0 sec after CS onset) improved as a function of increasing reinforcement ratio because of elevated response levels to the reinforced CS (CS+), but the effect was not persistent across trials in informed subjects. Performance in the first and second intervals did not reflect sequential increments and decrements as a function of reinforced and nonreinforced trials. Third-interval responses (7.1-9.9 sec after CS on nonreinforced trials) were not affected by schedule manipulations, but unconditioned responses diminished with increasing reinforcement ratio. Information about schedule contingencies led to superior discrimination of first-, second-, and third-interval responses and to suppression of unconditioned responses.

Adolescent↗

PubMed2006

The effects of lag schedules and preferred materials on variable responding in students with autism.

Effects of a Lag 1 reinforcement schedule on appropriate and varied responding to the social question, "What do you like to do?" and effects of the proportion of preferred stimuli present during training on the amount of varied responding in each session were investigated with students with autism. An ABAB reversal design and a multielement design were used to evaluate the effects of the Lag schedule and proportion of preferred stimuli, respectively. Results showed that a Lag 1 schedule was effective at increasing varied vocal responding for 2 of 3 participants. The proportion of stimuli that were preferred did not affect the amount of varied responding emitted.

Autistic Disorder↗

PubMedDate not supplied

Behavioral and cognitive-behavioral treatments for alcoholism: research opportunities.

This status report on behavioral and cognitive-behavioral treatments (CBT) for alcoholism is based on an article commissioned by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) for a review of its treatment research priorities. A number of gaps in knowledge and consequent research opportunities were identified. Additional work on cue exposure is needed to identify the most potent cues for drinking, and strategies for reducing the impact of drinking cues. Regarding contingency management, there is need for further studies with alcoholics, investigation of reinforcement schedules, and exploration of maintenance factors. With respect to the community reinforcement approach (CRA), research should identify its most effective elements and ways to sustain gains following treatment. The mediating role assigned to coping skills in the cognitive-behavioral model needs to be substantiated, and the effectiveness of various coping skills components must be determined. Further studies of relapse prevention (RP) are needed to improve the system for classifying relapse episodes, and to identify the most effective interventions for each type of episode. Studies of behavioral marital therapy should include identifying active ingredients, and testing hypothesized mediators of change. Patient-treatment matching strategies may help to identify clients likely to benefit from these strategies. Finally, given the overlap among these approaches, it is likely that research along the lines suggested will impact several of them and lead to a consolidation of their most effective elements into a common treatment package.

Adaptation, Psychological↗

PubMed1988

Effects of ethanol on mature offspring of mice given ethanol during pregnancy.

Male offspring of mice maintained on isocaloric liquid diets containing either 20% ethanol or sucrose derived calories during pregnancy were tested on their ability to discriminate different ethanol doses as adults. They were trained to lever-press for a food reward on each of two levers in an operant chamber, and were then maintained on an FR20 reinforcement schedule. After response rates stabilized, ethanol discrimination training was initiated by reinforcing only responses made on the drug appropriate-lever after i.p. injections of ethanol (1.0 g/kg) or water. After learning to discriminate the 1.0 g dose, the animals' ability to discriminate doses of 0.25, 0.50, 0.75, 1.0, and 1.5 g/kg was assessed by determining the percentage of responses made on the drug lever during a 2-min test period. Compared to sucrose controls, mice exposed to alcohol in utero learned the lever response more slowly and were less responsive to injected ethanol as evidenced by a reduced effect of the drug on response rates and by a reduction in their ability to discriminate the presence of injected ethanol. The results indicate that prenatal ethanol exposure can have long term consequences which reduce the effects of ethanol in fully mature animals.

Animals↗

PubMed2002

Sensitivity of children's behavior to probabilistic reward: effects of a decreasing-ratio lottery system on math performance.

Probabilistic reward has been shown to affect children's choice behavior in game-like activities. We examined the effects of a lottery system containing progressively lower exchange ratios on children's completion of math problems. Two of the 3 children completed problems above baseline levels until the chance of exchange dropped to 25%. This study describes a potentially useful method for examining reinforcement schedules in applied settings and extends previous research on probabilities of reinforcement.

Achievement↗

PubMed2000

Varying wheel-running reinforcer duration within a session: effect on the revolution-postreinforcement pause relation.

Previous investigations of wheel-running reinforcement that manipulated reinforcer duration across conditions showed a strong relation between wheel-running rate and average postreinforcement pause (PRP) duration. To determine if the basis of this relation across conditions was a local effect of fatigue or satiation, the correlation between revolutions run and the duration of the immediately following PRP was investigated under conditions in which reinforcer duration was either constant or variable within a session. Seven male Wistar rats pressed a lever on a fixed-interval 60-s reinforcement schedule with the opportunity to run for 60 s as the reinforcing consequence. In the constant-duration condition, the duration of the reinforcer was always 60 s. In the variable-duration condition, the duration of the reinforcer varied between 2 and 240 s with a mean of 60 s. Mean correlations between revolutions run and the next PRP duration for constant, variable, and constant conditions were -.07, .20, and -.07, respectively. Although the positive correlation in the variable-duration condition is consistent with an effect of momentary fatigue or satiation, little of the variance in PRP duration appears to be attributable to these factors.

Animals↗

PubMed1992

Phencyclidine established as a discriminative stimulus using ethanol as a reinforcer.

Long-Evans hooded rats were initially trained to lever press, in standard, operant conditioning chambers, according to a fixed-ratio 1 (FR1) reinforcement schedule using 0.06ml deliveries of 8% w/v ethanol as the reinforcer, during daily Monday-Friday, 1h experimental sessions. Next, experimental sessions were reduced to 0.5h, the FR value was increased to 5, and the rats were trained to discriminate 2.0mg/kg s.c. phencyclidine (PCP) from saline vehicle using standard, drug discrimination training procedures, with 8% ethanol as the reinforcer. Following training, dose-response tests with PCP (0.1-4.0mg/kg), ketamine (0.1-18mg/kg), dexoxadrol (1.0-5.6mg/kg) and morphine (1.0-9.0mg/kg) were conducted. More PCP-lever presses were emitted than saline-lever presses at several doses of PCP, ketamine, and dexoxadrol, indicating generalization from the 2.0mg/kg PCP stimulus. When morphine was tested, more saline-lever than PCP-lever presses were made, and percent PCP-lever pressing never exceeded an average of 12% at any dose tested. This study demonstrates that one drug of abuse, PCP, can serve as a discriminative stimulus when another drug of abuse, ethanol, serves as the reinforcing stimulus, and is the first explicit laboratory demonstration of drug discriminative stimulus control during drug self-administration.

Journal Article↗

PubMed1993

Schedule-induced defecation by rats during ratio and interval schedules of food reinforcement.

Lever pressing in rats was maintained by continuous and intermittent schedules of food while defecation was monitored. In Experiment 1, reinforcement densities were matched across variable-ratio and variable-interval schedules for three pairs of rats. Defecation occurred in all 3 rats on the variable-ratio schedule and in all 3 rats on the yoked variable-interval schedule. In Experiment 2, fixed-ratio and fixed-interval schedules with similar reinforcement densities maintained lever pressing. Defecation occurred in 3 of 4 rats on the fixed-ratio schedule and in 4 of 4 rats on the fixed-interval schedule. Almost no defecation occurred during continuous reinforcement in either experiment. These results demonstrate that defecation may occur during both ratio and interval schedules and that the inter-reinforcement interval is more important than the behavioral requirements of the schedule in generating schedule-induced defecation.

Animals↗

PubMed1965

RELATIVE RATE OF RESPONSE AND RELATIVE MAGNITUDE OF REINFORCEMENT IN MULTIPLE SCHEDULES.

Pigeons were trained on a multiple schedule in which the duration of access to grain reinforcement was varied independently in the two components. The relative response rate in one component was an increasing function of the relative duration of reinforcement in that component. The similarity of this interaction to that found in multiple schedules of different reinforcement frequency is discussed. Extinction data were also similar to those obtained after training on multiple schedules of different reinforcement frequency.

Animals↗

PubMed1988

Concurrent schedules: Interaction of reinforcer frequency and reinforcer duration.

Six pigeons were trained on concurrent variable-interval schedules with unequal reinforcer durations for the two responses. The schedules arranged on the two keys were kept equal while they were varied in absolute size. As the overall reinforcer rate was increased, both response-allocation and time-allocation measures of choice showed a trend toward indifference, and measures of sensitivity to reinforcer-duration ratios significantly decreased. Recent reports have shown that the generalized matching law cannot describe the changes in behavior allocation under constant delay-, duration-, or rate-ratios when changes are made in the absolute levels of each of these variables. The present results complement these findings by demonstrating that the concatenated generalized matching law cannot describe the interactions of two reinforcer variables on behavior allocation.

Journal Article↗

PubMed1977

[Effects of difenamizole on behavior maintained by schedule of positive reinforcement (author's transl)].

The anti-nociceptive dose of difenamizole, morphine, aminopyrine and aspirin was studied for effects on behavior maintained by schedule of positive reinforcement. Male, albino rats were trained to press a lever for food pellets on a fixed-ratio (FR) 10 and 30 schedule of reinforcement or a differential reinforcement of low rates of responding (DRL) schedule. Difenamizole (200 and 400 mg/kg, p.o.) produced a dose-related decrease in the response under FR-10 schedule. The response rate decrease observed under the FR-10 schedule was similar to that resulting from the oral administration of 400 mg/kg of aminopyrine. Response in the FR-30 schedule was not affected by any dose of difenamizole (100 approximately 400 mg/kg, p.o.) and aminopyrine (200 approximately 400 mg/kg, p.o.). In the response maintained by the DRL schedule, the overall response rate and the mean interresponse time were not altered significantly by most doses of difenamizole, aminopyrine and aspirin given, however, food reinforcement was decreased significantly with ingestion of these drugs. Morphine (20 mg/kg, p.o.) shortened the mean interresponse time and increased the response in DRL schedule. These results suggest that the central action of difenamizole is similar to that produced by aminopyrine, but not that produced by morphine.

Aminopyrine↗

PubMed2006

Second-order schedules of token reinforcement with pigeons: implications for unit price.

Four pigeons were exposed to second-order schedules of token reinforcement, with stimulus lights serving as token reinforcers. Tokens were earned according to a fixed-ratio (token-production) schedule, with the opportunity to exchange tokens for food (exchange period) occurring after a fixed number had been produced (exchange-production ratio). The token-production and exchange-production ratios were manipulated systematically across conditions. Response rates varied inversely with the token-production ratio at each exchange-production ratio. Response rates also varied inversely with the exchange-production ratio at each token-production ratio, particularly at the higher token-production ratios. At higher token-production and exchange-production ratios, response rates increased in token-production segments closer to exchange periods and food. Some conditions were conducted in a closed economy, in which the pigeons earned all their daily ration of food within the session. Relative to comparable open-economy conditions, response rates in the closed economy were less affected by changes in token-production ratio, resulting in higher levels of food intake and body weight. Some of the results are consistent with the economic concept of unit price, a cost-benefit ratio comprised of responses per unit of food delivery, but most are well accounted for by a consideration of the number of responses required to produce exchange periods, without regard to the amount of reinforcement available during those exchange periods.

Animals↗

PubMed1996

Within-session changes in responding during concurrent schedules with different reinforcers in the components.

Rats and pigeons responded on several concurrent schedules that provided different reinforcers in the two components (food and water for rats, Experiment 1; wheat and mixed grain for pigeons, Experiment 2). The rate of responding and the time spent responding on each component usually changed within the session. The within-session changes in response rates and time spent responding usually followed different patterns for the two components of a concurrent schedule. For most subjects, the bias and sensitivity to reinforcement parameters of the generalized matching law, as well as the percentage of the variance accounted for, decreased within the session. Negative sensitivity parameters were sometimes found late in the session for the concurrent food-water schedules. These results imply that within-session changes in responding could cause problems for assessing the validity of quantitative theories of concurrent-schedule responding when the components provide different reinforcers. They question changes in a general motivational state, such as arousal, as a complete explanation for within-session changes in responding. The results are compatible with satiation for, or sensitization-habituation to, the reinforcers as explanations.

Animals↗

PubMed1977

Second-order schedules of intravenous drug self-administration in rhesus monkeys.

Lever-pressing behavior was generated and maintained in 3 rhesus monkeys by intravenous infusions of morphine or cocaine under a second-order schedule of reinforcement. Under this schedule, every tenth lever-press response (FR 10) during a fixed interval of time produced a 2 sec stimulus light. The first FR 10 completed after a 60 min interval had elapsed produced the stimulus light and an intravenous infusion of morphine or cocaine. The stimulus light remained on for the duration of the drug infusion (50-60 sec). Sessions of morphine or cocaine presentation, each with distinct stimulus light conditions, alternated on a daily basis. Under this schedule, single doses of morphine from 0.125 to 1.0 mg/kg maintained high overall response rates (maximum of 40 Rs/min) in the pattern characteristic of fixed interval (FI) schedules of reinforcement. There was no functional relationship between the response-rates and the doses of morphine tested. The simultaneous infusion of naloxone (0.125 mg/kg/) with morphine (0.25 mg/kg) markedly decreased response rates. However, the infusion of the same dose of naloxone five min after the presentation of morphine failed to suppress self-administration behavior. Naloxone had no effects on cocaine-reinforced responding.

Animals↗