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.

SourceResearch connectionFrom yearThrough year

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

At least 451 records · Page 25Linked to original sources

PubMed1976

Alternative response training, differential reinforcement of other behavior, and extinction in squirrel monkeys (Saimiri sciureus).

In Experiment I, (a) extinction, (b) extinction plus reinforcement of a discrete alternative response, and (c) differential reinforcement of other behavior were each correlated with a different stimulus in a three-component multiple schedule. The alternative-response procedure more rapidly and completely suppressed behavior than did differential reinforcement of other behavior. Differential reinforcement of other behavior was slightly more effective than extinction alone. In Experiment II, reinforcement of specific alternative behavior during extinction and differential reinforcement of other behavior were used in two components, while one component continued to provide reinforcement for the original response. Once again, the alternative-response procedure was most effective in reducing responding as long as it remained in effect. However, the responding partially recovered when reinforcement for competing behavior was discontinued. In general, responding was less readily reduced by differential reinforcement of other behavior than by the specific alternative-response procedure.

Journal Article↗

PubMed1980

Reinforcement and punishment effects in concurrent schedules: A test of two models.

The joint effects of punishment and reinforcement on the pigeon's key-peck response were examined in three choice experiments conducted to compare predictions of Farley and Fantino's (1978) subtractive model with those made by Deluty's (1976) and Deluty and Church's (1978) model of punishment. In Experiment 1, the addition of equal punishment schedules to both alternatives of a concurrent reinforcement schedule enhanced the preference exhibited for the more frequent reinforcement alternative. Experiment 2 demonstrated decreases in the absolute response rate for each member of a concurrent reinforcement schedule when increasing frequencies of punishment were added to each alternative. Experiment 3 found that preference for the denser of two reinforcement schedules diminished when the absolute frequencies of reinforcement were increased by a constant factor and conditions of punishment for both alternatives were held constant. Diminished preferences were obtained regardless of whether the frequency of punishment associated with the denser reinforcement schedule was greater or less than that associated with the lean reinforcement alternative. The results from all three experiments uniquely supported Farley and Fantino's (1978) subtractive model of punishment and reinforcement.

Journal Article↗

PubMed1980

Alternative reinforcement effects on fixed-interval performance.

Pigeons' key pecks were reinforced with food on a fixed-interval schedule. Food also was available at variable time periods either independently of responding or for not key pecking (a differential-reinforcement-of-other-behavior schedule). The latter condition arranged reinforcement following the first pause of t seconds after it became available according to a variable-time schedule. This schedule allowed separation of the effects of pause requirements </= five-seconds and reinforcement frequency. The time spent pausing increased as the duration of the pause required for reinforcement increased from 0 to 30 seconds and as the frequency of reinforcement for pausing increased from 0 to 2 reinforcers per minute. Key pecking was more evenly distributed within each fixed interval with shorter required pauses and with more frequent reinforcement for pausing. The results complement those obtained with other concurrent schedules in which the same operant response was reinforced in both components.

Journal Article↗

PubMed1981

Discrete-trial choice in pigeons: Effects of reinforcer magnitude.

The preference of pigeons for large reinforcers which occasionally followed a response versus small reinforcers which invariably followed a response was studied in a discrete-trial situation. Two differently colored keys were associated with the two reinforcement alternatives, and preference was measured as the proportion of choice trials on which the key associated with uncertain reinforcement was pecked. A combination of choice and guidance trials insured that received distributions of reinforcement equalled the scheduled distributions. For five of six subjects, preference for the uncertain reinforcer appeared to be a linear function of the magnitude of the certain reinforcer. In addition, there was greater preference for the response alternative associated with uncertain reinforcement than would be expected on the basis of net reinforcer value.

Journal Article↗

PubMed1982

On the effects of component durations and component reinforcement rates in multiple schedules.

Four experiments, each using the same six pigeons, investigated the effects of varying component durations and component reinforcement rates in multiple variable-interval schedules. Experiment 1 used unequal component durations in which one component was five times the duration of the other, and the shorter component was varied over conditions from 120 seconds to 5 seconds. The schedules were varied over five values for each pair of component durations. Sensitivity to reinforcement rate changes was the same at all component durations. In Experiment 2, both component durations were 5 seconds, and the schedules were again varied using both one and two response keys. Sensitivity to reinforcement was not different from the values found in Experiment 1. In Experiment 3, various manipulations, including body-weight changes, reinforcer duration changes, blackouts, hopper lights correlated with keylights, and overall reinforcement rate changes were carried out. No reliable increase in reinforcement sensitivity resulted from any manipulation. Finally, in Experiment 4, reinforcement rates in the two components were kept constant and unequal, and the component durations were varied. Shorter components produced significantly increased response rates normally in the higher reinforcement rate component, but schedule reversals at short component durations eliminated the response rate increases. The effects of component duration on multiple schedule performance cannot be interpreted as changing sensitivity to reinforcement nor to changing bias.

Journal Article↗

PubMed1983

Quantification of rats' behavior during reinforcement periods.

What is treated as a single unit of reinforcement often involves what could be called a reinforcement period during which two or more acts of ingestion may occur, and each of these may have associated with it a series of responses, some reflexive, some learned, that lead up to ingestion. Food-tray presentation to a pigeon is an example of such a "reinforcement period." In order to quantify this behavior, a continuous-reinforcement schedule was used as the reinforcement period and was chained to a fixed-ratio schedule. Both fixed-ratio size and reinforcement-period duration were manipulated. Rats were used as subjects, food as reinforcement, and a lever press as the operant. Major findings included (a) a rapid decline in response rates during the first 15 to 20 seconds of the reinforcement periods, and (b) a strong positive relationship between these response rates and the size of the fixed ratio. Also revealed was a short scallop not normally found in fixed-ratio response patterns, whose length was a function of fixed-ratio size and reinforcement-period duration. It is suggested that rapidly fluctuating excitatory processes can account for many of these findings and that such processes are functionally significant in terms of behavioral compensation.

Journal Article↗

PubMed1987

Control of responding during stimuli that precede transitions in reinforcement frequency.

Pigeons' responses were reinforced on a variant of a mixed variable-interval extinction schedule of reinforcement in which the transition to the higher reinforcement rate was signaled by a trace stimulus projected on the response key prior to the onset of the component correlated with food delivery. In the first of two experiments, the duration of the trace stimulus preceding the component correlated with food delivery was varied from 1.5 to 50.0 s and in the second experiment, the reinforcement frequency in the same component was varied from 10 to 60 reinforcers per hour. Pigeons pecked at the trace stimulus preceding the onset of the component correlated with food delivery even though responding was not reinforced in its presence and only one of the changes in reinforcement rate (i.e., from extinction to reinforcement) was signaled. The rate of pecking during the trace stimulus was a function of its duration but not of the reinforcement frequency in the following component. Higher rates generally occurred at the shorter trace-stimulus durations. Component responding following the offset of the trace stimulus was under discriminative control of the trace stimulus whether or not responding occurred in the presence of the trace stimulus.

Journal Article↗

PubMed1993

Multiple-choice procedure: an efficient approach for investigating drug reinforcement in humans.

Two experiments demonstrated the efficiency of assessing drug reinforcement in humans by using a novel multiple-choice procedure. The distinguishing characteristic of the procedure is that it arranges intermittent reinforcement for choices between pairs of potential reinforcers. The procedure has three key operations: (1) a subject is exposed to the potential reinforcers; (2) a subject then makes two or more choices on a questionnaire; for each choice, the subject is required to choose one of two potential reinforcers (e.g. drug vs. drug choices and/or drug vs. money choices); and (3) subsequently only one of the choices, randomly selected, is reinforced. In the present experiments, two variations of the multiple-choice procedure were evaluated in twelve male drug abusers. Both experiments assessed the reinforcing effects of three drug conditions (200 and 400) mg/70kg pentobarbital and placebo) which were presented no more often than every to other day. The experiments demonstrated dose-related choice of pentobarbital over money as well as choice of a higher dose of pentobarbital over a lower dose or placebo. Orderly data were generated with a single-session exposure to each drug condition. Multiple-choice procedures should have applicability, not only to the investigation of drug reinforcement, but also to the study of non-drug reinforcement in humans.

Journal Article↗

PubMed1994

Ethanol as a reinforcer: a review of laboratory studies of non-human primates.

This article reviews studies of ethanol self-administration in non-human primates. Between approximately 1960 and 1980 research programs at three university medical centers (Michigan, Minnesota and Baylor) established that ethanol could function as a reinforcer when delivered either intravenously, intragastrically or orally. Variables such as session length, dose and intermittent reinforcement schedules were examined, and tolerance and physiological dependence on ethanol were also studied. Procedures used to establish abused drugs as reinforcers via the intravenous, intragastric and oral route are also effective in the particular case of ethanol. Under conditions of limited access (e.g. 3h per day), the variables that control behavior reinforced by ethanol are the same as those that govern behavior reinforced by other drugs. Moreover, the functional relations between these variables and ethanol-reinforced responding are similar to the functional relations between the same variables and other drug reinforcers. However, with continuous 24h access to ethanol, differences appear with respect to other sedative-hypnotic drugs. In contrast to these other drugs, intravenous ethanol use results in a suppression of food intake, weight loss, self-initiated abstinence, and often, death. When intravenous and oral ethanol self-administration are compared, two important differences emerge: the maximum intakes via the intravenous route exceed the maximum intakes via the oral route, and, perhaps surprisingly, the doses required to maintain responding are lower with the oral route. Studies since 1980 have increased the scope of ethanol reinforcement research and also corroborated and extended earlier findings. In summary, ethanol can function as an effective reinforcer for non-human primates.

Journal Article↗

PubMed1992

Operant place conditioning measures examined using two nondrug reinforcers.

Detection of water and social play reinforcers by a place conditioning method based on instrumental conditioning was investigated in rats and compared to detection by conditioned place preference, a method currently used primarily to measure drug reinforcement. Operant place conditioning measures of reinforcement were choices between the reward and nonreward chambers during an apparatus exploration test and during a discrete-trials choice test and also, in some experiments, choices and latencies of chamber entry during training. Three of these four measures showed larger reinforcement effects than did the conditioned place preference measure of relative time spent in the reward chamber. By all reinforcement measures, conditioned place preference training was effective with water reinforcement but was ineffective with social reinforcement. Operant place conditioning was effective with both reinforcers by all measures.

Animals↗

PubMed1993

Effects of reinforcer limitations on fixed-ratio responding during repeated administration of chlorpromazine.

Key-pecking was maintained under a 30-response fixed-ratio schedule of food presentation and pigeons received 30 mg/kg/day chlorpromazine immediately prior to experimental sessions. After responding stabilized during chronic drug and animals were receiving all available reinforcers, the time available for receiving reinforcers was systematically varied. When that time was decreased, animals initially received fewer reinforcers but responding subsequently increased to an extent that animals once more received all available reinforcers. When that time was again increased, responding once again decreased but only to an extent that animals continued receiving all available reinforcers. During subsequent reversals of the time for reinforcer availability, responding increased or decreased to an extent always resulting in the maximum number of reinforcers. When drug was discontinued, responding returned to predrug levels. These results demonstrate that effects of chronically administered chlorpromazine were influenced by both drug activity at its site of action and by the behavioral process of reinforcement.

Animals↗

PubMed1982

Immediate and delayed reinforcement on WISC-R performance for mentally retarded students.

Thirty white mentally retarded children were administered the WISC-R under one of three conditions: standardized testing conditions, standardized plus immediate reinforcement, standardized plus delayed reinforcement. One reinforcement group earned tokens immediately after each correct response and the other reinforcement group received their earned tokens halfway through and at the end of the IQ test. Both reinforcement groups exchanged their tokens for a variety of backup reinforcers at the halfway point and at the end of the test. Both the immediate and delayed reinforcement groups showed significantly better performance than the standardized testing group, although the two reinforcement groups did not differ from one another. Half of the children in each of the groups that earned tokens scored above the mentally impaired range while only one child in the standardized testing group scored above the mentally impaired level. Implications for the use of intelligence tests for mentally retarded students are discussed.

Child↗

PubMed1998

Ethanol's effects on operant responding: differentiating reinforcement efficacy and motor performance.

The purpose of this study was to examine the effects of ethanol on operant responding in rats. Drugs may affect response rates by several mechanisms, including altering motor performance or sensitivity to reinforcement. These two processes can be dissociated by applying a quantitative model of reinforced responding the response-strength equation, to response rates obtained during multiple variable-interval (VI) schedules of reinforcement. This equation has two fitted parameters. One (k) is thought to measure changes in motor performance, and the other (Re) is thought to measure changes in reinforcement efficacy. In experimental sessions, rats earned sucrose reinforcement on a seven-component multiple VI operant schedule. The average intervals varied from 108 to 3 s and provided reinforcement rates from 30 to 1200/h. Following stable baseline performance, rats were injected intraperitoneally prior to sessions with different doses of ethanol: 0.0, 0.3, 0.6. and 0.9 g/kg. Low to moderate doses of ethanol (0.3 and 0.6 g/kg) significantly decreased response rates on several of the VI schedules but did not alter either of the fitted parameters, suggesting that these doses of ethanol did not affect motor performance or sensitivity to reinforcement. The 0.9 g/kg dose decreased responding maintained by many of the VI schedules and significantly increased the Re parameter, suggesting that the sucrose became relatively less efficacious in ethanol compared to vehicle sessions. This relatively high dose of ethanol, however, did not alter responding maintained by the richest reinforcement schedule, and it did not affect motor performance as defined by the k parameter. These results suggest that, within this paradigm, ethanol affects motivation to respond rather than ability to respond.

Analysis of Variance↗

PubMed1976

DRL performance, extinction, and secondary reinforcement: role of appetitive value of food in mice with septal lesions.

Normal mice and mice with septal lesions were trained on a differential-reinforcement-for-low-rates-of-responding (DRL 8-sec) schedule for the reinforcement varying in incentive value. Dilution of diet increased the number of reinforcements received by mice with septal lesions. In Experiments 2 and 3 the effects of septal lesions on resistance to extinction and continuous reinforcement training and the strength of secondary reinforcement were investigated. Changes in reinforcement value modified the septal lesion effects in both cases. All three experiments demonstrated the alteration of the septal lesion effect through a change in the appetitive value of the reinforcement. The results suggest that one of the mechanisms by which septal lesions impair DRL performance is an enhancement of reinforcing properties of food.

Acoustic Stimulation↗

PubMed2005

Nucleus accumbens core lesions retard instrumental learning and performance with delayed reinforcement in the rat.

BACKGROUND: Delays between actions and their outcomes severely hinder reinforcement learning systems, but little is known of the neural mechanism by which animals overcome this problem and bridge such delays. The nucleus accumbens core (AcbC), part of the ventral striatum, is required for normal preference for a large, delayed reward over a small, immediate reward (self-controlled choice) in rats, but the reason for this is unclear. We investigated the role of the AcbC in learning a free-operant instrumental response using delayed reinforcement, performance of a previously-learned response for delayed reinforcement, and assessment of the relative magnitudes of two different rewards. RESULTS: Groups of rats with excitotoxic or sham lesions of the AcbC acquired an instrumental response with different delays (0, 10, or 20 s) between the lever-press response and reinforcer delivery. A second (inactive) lever was also present, but responding on it was never reinforced. As expected, the delays retarded learning in normal rats. AcbC lesions did not hinder learning in the absence of delays, but AcbC-lesioned rats were impaired in learning when there was a delay, relative to sham-operated controls. All groups eventually acquired the response and discriminated the active lever from the inactive lever to some degree. Rats were subsequently trained to discriminate reinforcers of different magnitudes. AcbC-lesioned rats were more sensitive to differences in reinforcer magnitude than sham-operated controls, suggesting that the deficit in self-controlled choice previously observed in such rats was a consequence of reduced preference for delayed rewards relative to immediate rewards, not of reduced preference for large rewards relative to small rewards. AcbC lesions also impaired the performance of a previously-learned instrumental response in a delay-dependent fashion. CONCLUSIONS: These results demonstrate that the AcbC contributes to instrumental learning and performance by bridging delays between subjects' actions and the ensuing outcomes that reinforce behaviour.

Animals↗

PubMed2004

Effects of modeling versus instructions on sensitivity to reinforcement schedules.

This study examined the effects of modeling versus instructions on the choices of 3 typically developing children and 3 children with attention deficit hyperactivity disorder (ADHD) whose academic responding showed insensitivity to reinforcement schedules. During baseline, students chose between successively presented pairs of mathematics problems associated with different variable-interval schedules of reinforcement. After responding proved insensitive to the schedules, sessions were preceded by either instructions or modeling, counterbalanced across students in a multiple baseline design across subjects. During the instruction condition, students were told how to distribute responding to earn the most reinforcers. During the modeling condition, students observed the experimenter performing the task while describing her distribution of responding to obtain the most reinforcers. Once responding approximated obtained reinforcement under either condition, the schedules of reinforcement were changed, and neither instruction nor modeling was provided. Both instruction and modeling interventions quickly produced patterns of response allocation that approximated obtained rates of reinforcement, but responding established with modeling was more sensitive to subsequent changes in the reinforcement schedules than responding established with instructions. Results were similar for students with and without ADHD.

Achievement↗

PubMed1963

Concurrent performances: reinforcement interaction and response independence.

When a pigeon's pecks on two keys were reinforced concurrently by two independent variable-interval (VI) schedules, one for each key, the response rate on either key was given by the equation: R(1)=Kr(1)/(r(1)+r(2))(5/6), where R is response rate, r is reinforcement rate, and the subscripts 1 and 2 indicate keys 1 and 2. When the constant, K, was determined for a given pigeon in one schedule sequence, the equation predicted that pigeon's response rates in a second schedule sequence. The equation derived from two characteristics of the performance: the total response rate on the two keys was proportional to the one-sixth power of the total reinforcement rate provided by the two VI schedules; and, the pigeon matched the relative response rate on a key to the relative reinforcement rate for that key. The equation states that response rate on one key depends in part on reinforcement rate for the other key, but implies that it does not depend on response rate on the other key. This independence of response rates on the two keys was demonstrated by presenting a stimulus to the pigeon whenever one key's schedule programmed reinforcement. This maintained the reinforcement rate for that key, but reduced the response rate almost to zero. The response rate on the other key, nevertheless, continued to vary with reinforcement rates according to the equation.

Animals↗

PubMed1967

Behavioral contrast and relative reinforcement frequency in two multiple schedules.

After preliminary variable-interval training, one group of pigeons was trained on a series of multiple variable-interval low-rate reinforcement schedules, while another group was trained on a series of multiple variable-interval fixed-ratio reinforcement schedules. Contrast effects were observed as variable-interval baseline rate changed in a direction away from the change in reinforcement frequency in the other component. The effects of the variable-interval component on performance in the low-rate and fixed-ratio reinforcement components in the multiple schedules were assessed by comparing the birds' performances on each of these schedules alone. Fixed-ratio reinforcement schedules showed a susceptibility to contrast effects, low-rate reinforcement schedules did not. The rate of reinforcement in fixed-ratio schedules at which no interaction occurred in the multiple schedules was higher than that in variable-interval 1-min schedules, suggesting that pigeons may prefer time-based, rather than response-based, reinforcement.

Animals↗