Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “REINFORCEMENT”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 793 records · Page 44Linked to original sources
PubMed2002

Role of dopamine in drug reinforcement and addiction in humans: results from imaging studies.

The involvement of dopamine (DA) in drug reinforcement is well established, but much less in known about its contribution to addiction. We have used positron emission tomography to investigate in humans the role of DA in drug reinforcement, addiction and drug vulnerability. We have shown that during drug intoxication increases in striatal DA are associated with the drug's reinforcing effects only if the DA changes occur rapidly. These results corroborate the relevance of drug-induced DA increases and of pharmacokinetics in the rewarding effects of drugs in humans. During withdrawal, we have shown significant reductions in DA D(2) receptors and in DA release in drug abusers, which is likely to result in decreased sensitivity to non-drug-related reinforcing stimuli. The DA D(2) reductions were associated with decreased activity in the orbitofrontal cortex, which we postulate is one of the mechanisms underlying compulsive drug administration in the addict. In fact, during craving the orbitofrontal cortex becomes hyperactive in proportion to the desire for the drug. In non-drug-abusing subjects striatal DA D(2) receptors levels predicted the reinforcing responses to stimulant drugs, providing evidence that striatal DA D(2) receptors modulate reinforcing responses to stimulants in humans and may contribute to the predisposition for drug self-administration.

Dopamine↗
PubMed2003

The behavioral economics of cigarette smoking: The concurrent presence of a substitute and an independent reinforcer.

The present study examined the consumption of cigarettes and two alternative reinforcers in dependent smokers. Cigarette price (response requirement) increased across sessions while alternatives were available at a fixed price in four phases of availability: (1). cigarettes alone; (2). cigarettes and nicotine gum; (3). cigarettes and money; and (4). cigarettes, nicotine gum, and money. Cigarette consumption decreased with increasing price throughout. In the cigarette and nicotine gum phase, nicotine gum consumption increased with cigarette price, indicating nicotine gum to be a substitute for cigarettes. In the cigarette and money phase, money consumption increased slightly with cigarette price, indicating money to be an independent reinforcer for cigarettes. When all three reinforcers were present, money again served as an independent reinforcer. During this phase, nicotine gum consumption increased marginally, but the small magnitude of increase suggests that nicotine gum functioned as an independent reinforcer rather than a substitute. Cigarette consumption decreased modestly when nicotine gum was available, and to a larger extent when money or both alternatives were available. The results highlight the potential for an independent reinforcer such as money to be more effective at reducing drug use than a pharmacological substitute.

Behavior, Addictive↗
PubMed2004

Acute marijuana effects on response-reinforcer relations under multiple variable-interval schedules.

Acute marijuana administration may alter response-reinforcer relationships via a change in reinforcer efficacy, but may also impair coordination and motor function. One approach to evaluating drug effects on both motor function and reinforcer efficacy involves fitting the matching law equation to data obtained under multiple variable interval (VI) schedules. The present report describes an experiment that examined the effects of acute marijuana on response properties using this approach. Six human subjects responded under a multiple VI schedule for monetary reinforcers after smoking placebo and two active doses of marijuana. The low marijuana dose produced unsystematic changes in responding. As measured by the matching law equation parameters (k and rB), at the high dose five subjects showed a decrease-motor-related properties of response rate and four subjects' responding indicated a decrease in reinforcer efficacy. These data raise the possibility that, at high doses, marijuana administration alters both motor function and reinforcer efficacy.

Administration, Inhalation↗
PubMed2005

Sensitization of the reinforcing effects of self-administered cocaine in rats: effects of dose and intravenous injection speed.

Speed of drug onset is assumed to be an important determinant of the abuse liability of a drug. Studies in human and non-human primates suggest that the subjective and reinforcing effects of cocaine can be influenced by route of administration and/or speed of intravenous injection. Sensitization to the reinforcing effects of cocaine was studied in rats and the effects of various injection durations (i.e. speed of injection) on the development of sensitization was examined using a progressive ratio schedule. In addition, the effects of cocaine dose on sensitization and the effects of injection duration on the acute reinforcing effects of cocaine were examined. The initial study demonstrated that the development of sensitization (i.e. progressive increases in breakpoints) was dose-dependent. A robust sensitization of the reinforcing effects of cocaine was replicated in animals receiving cocaine at the highest rate (i.e. shortest duration; 5 s), but not in animals receiving the same dose over 25 or 50 s. Subsequent testing revealed that injection duration did not have profound effects on the acute reinforcing effects of cocaine (assessed by breakpoints or rate of responding on a fixed ratio schedule). These findings are similar to recent studies demonstrating that the development of sensitization, but not the acute responsivity, to cocaine's locomotor-activating effects are influenced by rate of intravenous injection. Taking these findings together, we hypothesize that the process of drug addiction involves both the acute reinforcing effects and the development of sensitization.

Animals↗
PubMed2006

Reinforcing effects of central ethanol injections in newborn rat pups.

BACKGROUND: Newborn rat pups readily ingest ethanol of low to moderate concentrations and are sensitive to its reinforcing effects. Given that early ethanol exposure can promote its future abuse, it is vital to discover the mechanisms behind reinforcing effects of ethanol at this stage of life. METHODS: Cesarean-delivered 3- to 4-hour-old rat pups were exposed to lemon odor (unconditioned stimulus) either paired or explicitly unpaired with central injections of saline or ethanol (25, 50, 100, 200, or 400 mg%) in a volume of 1 muL. One hour following conditioning subjects were tested on a surrogate nipple providing water in the presence of lemon odor. Reinforcement from ethanol's central effects was indexed by significantly greater attachment time on a lemon-scented nipple in paired subjects than in unpaired or saline controls. RESULTS: Rats centrally injected with 25 to 200 mg% ethanol in the presence of lemon odor spent significantly more time attached to a lemon-scented surrogate nipple providing water than did their saline-injected or unpaired counterparts. Those injected with 400 mg% ethanol did not differ from their corresponding controls. No detectable brain alcohol content was found in the assay of whole brain for ethanol levels. CONCLUSIONS: These results indicate that 3- to 4-hour-old rat pups find central injections of 25 to 200 mg% ethanol reinforcing. This procedure virtually eliminates ethanol's chemosensory or caloric attributes as the source of ethanol reinforcement. The present classical olfactory conditioning paradigm can be used to further study mechanisms of this apparently pharmacological reinforcement by ethanol in newborn rat pups.

Alcohol Drinking↗
PubMed2003

The reinforcing efficacy of psychostimulants in rhesus monkeys: the role of pharmacokinetics and pharmacodynamics.

This study was undertaken to investigate pharmacological variables that influence the reinforcing efficacy of psychostimulants. Rhesus monkeys (n = 9) responded under a within-session, exponentially increasing, progressive ratio schedule of cocaine reinforcement. Doses of cocaine, methylphenidate (MP), cocaine analogs [(+/-)-2beta-propanoyl-3beta-(2-naphthyl)-tropane (WF-23), HD-23; (+/-)-2beta-propanoyl-3beta-(2-isopropenyl)tropane (WF-60), HD-60; and 2beta-propanoyl-3beta-(4-tolyl)-tropane (HD-11, WF-11), and 2beta-propanoyl-3beta-(4-tolyl)-tropane (HD-11, WF-11), PTT], and MP analogs [(alphaR,2R)-alpha-(2-naphthalenyl)-2-piperidineacetic acid methyl ester, HDMP-28; and (alphaR,2S)-alpha-(2-naphthalenyl)-2-pyrrolideneacetic acid methyl ester, HDMP-29] that varied in their pharmacokinetic and pharmacodynamic properties were substituted for cocaine. These drugs were chosen according to their selectivity for dopamine transporters (DAT) and 5-hydroxytryptamine (serotonin) transporters (5-HTT) as assessed in rodents and their duration of action. In addition, data pertaining to the rate of onset at DAT were collected for the cocaine analogs using an ex vivo binding assay in rodent tissue. Finally, the pharmacodynamic profile of select drugs was confirmed in primate brain tissue. All drugs had reinforcing effects except HDMP-29. The rank ordering of the peak breaking points (BPs) was cocaine = MP = HDMP-28 >or= HD-60 >or= PTT >or= HD-23 > HDMP-29. The time to peak DAT occupancy for the cocaine analogs was greater than 30 min. The potency to maintain peak BP was significantly correlated with DAT affinity. There was not a linear relationship between monoamine transporter affinity and reinforcing efficacy, but it appeared that in nonhuman primates there is a range of DAT affinity under which maximal responding is maintained. Interestingly, the 5-HTT-selective cocaine analog HD-60 functioned robustly as a reinforcer at several doses in all monkeys tested. These data question the dogma regarding the role of pharmacokinetic factors and the relative influence of DAT and 5-HTT in stimulant reinforcement.

Animals↗
PubMed2005

Relationship between the serotonergic activity and reinforcing effects of a series of amphetamine analogs.

It has been reported that among drugs with mixed actions on central nervous system monoamine systems, increased serotonergic activity is associated with decreased potency as a reinforcer. The present experiment was designed to examine this relationship for amphetamine analogs that varied in serotonin releasing potency and to evaluate whether serotonergic actions can affect reinforcing efficacy. Compounds PAL 313 and 314 are para- and meta-methylamphetamine, respectively. PAL 303 and 353 are para- and meta-fluoroamphetamine, respectively. All compounds had similar potencies as in vitro releasers of dopamine (DA) and norepinephrine (NE) but differed in potency for 5-hydroxytryptamine (serotonin) (5-HT) release [EC(50) (nanomolar) PAL 313 = 53.4; PAL 314 = 218; PAL 303 = 939; PAL 353 = 1937]. When made available to rhesus monkeys (Macaca mulatta)(n = 4) for self-administration under a fixed-ratio 25 schedule, all were positive reinforcers with biphasic dose-response functions (0.003-1.0 mg/kg) and were equipotent. PAL 313 was self-administered at a lower rate than the other compounds, which were indistinguishable. Under a progressive-ratio schedule (n = 5), all drugs were positive reinforcers. Dose-response functions increased to a maximum or were biphasic (0.01-1.0 mg/kg), and drugs were equipotent. At maximum, PAL 313 maintained less responding than other PAL drugs, which maintained similar maxima. Thus, all compounds were positive reinforcers under both schedules, consistent with their potent DA actions. Responding was lower when 5-HT potency was higher and comparable with DA and NE potency. The results suggest that the mechanism for this effect involves a decrease in reinforcing potency and efficacy among monoamine releasing agents when 5-HT releasing potency is increased relative to DA.

Amphetamine↗
PubMed2003

Carryover effects of free reinforcement on children's work completion.

Patterns of behavior that persist during transition to a new set of contingencies are referred to as reinforcement history or carryover effects. The authors examined the carryover effects of a fixed-time (FT) schedule of free reinforcement on children's work completion and accuracy. Two female students with learning disabilities participated. During an initial concurrent-choice condition, both children completed more difficult problems reinforced on a richer schedule than easy problems reinforced on a leaner schedule. Exposure to an FT schedule was alternated with subsequent choice conditions in an ABABA design to examine potential carryover effects. During FT conditions, the children completed both types of problems with more errors. During subsequent choice conditions, errors were high initially but decreased, and both children completed easy problems for the first few sessions despite their leaner reinforcement schedule. The potential for detrimental effects of free reinforcement on children's work completion is discussed.

Achievement↗
PubMed1998

Effect of reinforcement on facial responsivity and persistence in children with attention-deficit hyperactivity disorder.

Children with Attention Deficit-Hyperactivity Disorder (ADHD) may learn poorly under conditions of inconsistent (partial) reinforcement because they are easily frustrated and fail to develop persistence. To test this hypothesis, a nonsense word spelling task was used with 22 ADHD and 20 control children to investigate the effects of partial and continuous reinforcement on facial responsivity (frustration measure), words spelled correctly (learning performance measure), and persistence ratings. Partially reinforced ADHD children manifested higher levels of frustration in both acquisition and extinction than any other group and gave significantly lower persistence ratings across acquisition than partially reinforced control children. ADHD children spelled fewer words correctly than controls, regardless of reinforcement schedule. These findings suggest that partial reinforcement training develops persistence in normal but not ADHD children. The findings have theoretical implications for the etiology of ADHD as well as practical implications for designing behavior modification programs to treat ADHD.

Attention↗
PubMed2001

Alcohol effects on inhibitory and activational response strategies in the acquisition of alcohol and other reinforcers: priming the motivation to drink.

OBJECTIVE: Low doses of alcohol can increase (i.e., prime) operant responding for alcohol in social drinkers. The present study tested the degree to which alcohol increased subjects' responding for the drug by biasing their reward-acquisition strategies in favor of response activation, and away from inhibitory responding. METHOD: Thirty-two social drinkers received either a priming dose of alcohol (0.55 g/kg) or a placebo, prior to performing a stop-signal task to earn their choice of alcoholic drinks or alternative monetary reinforcers. RESULTS: When alternative monetary reinforcement was of low value, alcohol was chosen more often by subjects who received the priming dose versus those who received the placebo. The priming dose also affected reward-acquisition strategies. Subjects who received the priming dose obtained reinforcers by increased response activation and reduced response inhibition. By contrast, those who received the placebo obtained reinforcers via a combination of activational and inhibitory responding. CONCLUSIONS: The results of this study show that alcohol might affect cognitive processes involved in drug reinforcement. By combining traditional operant measures of drug reinforcement with tasks that assess cognitive processes, this research offers a promising new strategy to study the role of cognitive processes in the abuse potential of a wide range of drugs.

Adult↗
PubMed1981

"Do I have to be good all day? The timing of delayed reinforcement as a factor in generalization.

Delayed reinforcement, sometimes delivered just after the setting in which the critical behavior had occurred (Early), and sometimes delivered only after several further settings had been encountered (Late), was used to improve a variety of behaviors in seven preschool children, and to control their generalization. Performance of those behaviors was measured in two classroom settings: the Contingent setting, within which performance of the specified behavior determined the latter (Early or Late) reinforcement, and the Generalization setting, in which there were no experimental contingencies, immediate or delayed, for the performance of the same behavior. Performances by all children in the Contingent setting were controlled by delayed reinforcement, whether Early or late. All children showed consistent generalization from the Contingent setting to the Generalization setting during the Late condition, when reinforcement was delivered at the end of the school day. Generalization did not occur during the Early condition, when reinforcement was provided immediately after the Contingent setting (prior to the Generalization setting), unless that condition had been preceded by a Late condition (as it was for S6 and S7). The results suggest that the Late timing of delayed reinforcement was an effective and efficient generalization-promotion technique for performances that did not generalize spontaneously.

Behavior Therapy↗
PubMed1984

Errorless learning: reinforcement contingencies and stimulus control transfer in delayed prompting.

Delayed prompting can produce errorless discrimination learning. There is inherent in the procedure a disparity in reinforcement density which favors unprompted over prompted responses. We used three schedules of reinforcement to investigate the impact of reinforcement probability on transfer of stimulus control. One schedule of reinforcement was equal prior to and following a prompt (CRF/CRF), the second favored unprompted responses (CRF/FR3), and the third favored responses following the prompt (FR3/CRF). Experimental questions concerned the probability of errors, the probability of transfer, and the rate of transfer in the context of delayed prompting. Transfer was accelerated when reinforcement probability favored anticipatory responding. The schedule that favored prompted responses did not prevent a shift to unprompted responding. Errors were infrequent across procedures. Reinforcement probability contributes to but does not entirely determine transfer of stimulus control from a delayed prompt.

Adolescent↗
PubMed1987

Negative reinforcement in applied behavior analysis: an emerging technology.

Although the effects of negative reinforcement on human behavior have been studied for a number of years, a comprehensive body of applied research does not exist at this time. This article describes three aspects of negative reinforcement as it relates to applied behavior analysis: behavior acquired or maintained through negative reinforcement, the treatment of negatively reinforced behavior, and negative reinforcement as therapy. A consideration of research currently being done in these areas suggests the emergence of an applied technology on negative reinforcement.

Aversive Therapy↗
PubMed1996

Analysis of free-time contingencies as positive versus negative reinforcement.

Providing a short break contingent on completed work may increase responding through positive reinforcement (e.g., access to preferred activities) or negative reinforcement (e.g., escape form work). In this investigation, three analyses conducted with a boy with profound mental retardation showed that (a) a 20-s break increased responding more than a positive reinforcer (cola) did, and (b) the reinforcing effect of a 20-s break were affected by the availability of positive reinforcers during the break were affected by the availability of positive reinforcers during the break.

Autistic Disorder↗
PubMed1997

The use of positive and negative reinforcement in the treatment of escape-maintained destructive behavior.

We identified 3 clients whose destructive behavior was sensitive to negative reinforcement (break from tasks) and positive reinforcement (access to tangible items, attention, or both). In an instructional context, we then evaluated the effects of reinforcing compliance with one, two, or all of these consequences (a break, tangible items, attention) when destructive behavior produced a break and when it did not (escape extinction). For 2 clients, destructive behavior decreased and compliance increased when compliance produced access to tangible items, even though destructive behavior resulted in a break. For 1 client, extinction was necessary to reduce destructive behavior and to increase compliance. Subsequently, when the schedule of reinforcement for compliance was faded for all clients, destructive behavior was lower and fading proceeded more rapidly when compliance produced multiple functional reinforcers (i.e., a break plus tangible items or attention) and destructive behavior was on extinction. The results are discussed in terms of the effects of relative reinforcement value and extinction on concurrent operants.

Child↗
PubMed1999

A comparison of presession and within-session reinforcement choice.

Single- and concurrent-operants procedures were used to evaluate the effects of two reinforcement conditions on the free-operant responding of 3 individuals with developmental disabilities and 1 with attention deficit disorder. In the presession choice condition, prior to each session the participant chose one item from an array of three different highly preferred stimuli. This item was delivered by the experimenter on each reinforcer delivery during that session. In the within-session choice condition, each reinforcer delivery consisted of placing an array of three different highly preferred stimuli in front of the participant, who was allowed to select one. Only one of the two reinforcement conditions was in effect for any particular session in single-operant phases. Buttons associated with each reinforcement condition were present, and the participant could allocate responses to one or the other in concurrent-operants phases. Data showed substantially more responding to the button associated with within-session choice than presession choice during concurrent-operants phases. This effect was not as apparent during single-operant phases, suggesting that a concurrent-operants procedure provided the more sensitive evaluation of within-session and presession reinforcer choice effects.

Child↗
PubMed1999

An evaluation of the properties of attention as reinforcement for destructive and appropriate behavior.

The analogue functional analysis described by Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994) identifies broad classes of variables (e.g., positive reinforcement) that maintain destructive behavior (Fisher, Ninness, Piazza, & Owen-DeSchryver, 1996). However, it is likely that some types of stimuli may be more effective reinforcers than others. In the current investigation, we identified 2 participants whose destructive behavior was maintained by attention. We used concurrent schedules of reinforcement to evaluate how different types of attention affected both destructive and appropriate behavior. We showed that for 1 participant praise was not an effective reinforcer when verbal reprimands were available; however, praise was an effective reinforcer when verbal reprimands were unavailable. For the 2nd participant, we identified a type of attention that effectively competed with verbal reprimands as reinforcement. We then used the information obtained from the assessments to develop effective treatments to reduce destructive behavior and increase an alternative communicative response.

Aggression↗
PubMed2000

Response acquisition under direct and indirect contingencies of reinforcement.

We compared the effects of direct and indirect reinforcement contingencies on the performance of 6 individuals with profound developmental disabilities. Under both contingencies, completion of identical tasks (opening one of several types of containers) produced access to identical reinforcers. Under the direct contingency, the reinforcer was placed inside the container to be opened; under the indirect contingency, the therapist held the reinforcer and delivered it to the participant upon task completion. One participant immediately performed the task at 100% accuracy under both contingencies. Three participants showed either more immediate or larger improvements in performance under the direct contingency. The remaining 2 participants showed improved performance only under the direct reinforcement contingency. Data taken on the occurrence of "irrelevant" behaviors under the indirect contingency (e.g., reaching for the reinforcer instead of performing the task) provided some evidence that these behaviors may have interfered with task performance and that their occurrence was a function of differential stimulus control.

Adult↗