PubMed Health⌕ Search

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 343 records · Page 19Linked to original sources
PubMed2001

EMG biofeedback: the effects of CRF, FR, VR, FI, and VI schedules of reinforcement on the acquisition and extinction of increases in forearm muscle tension.

Biofeedback was used to increase forearm-muscle tension. Feedback was delivered under continuous reinforcement (CRF), variable interval (VI), fixed interval (FI), variable ratio (VR), and fixed ratio (FR) schedules of reinforcement when college students increased their muscle tension (electromyograph, EMG) above a high threshold. There were three daily sessions of feedback, and Session 3 was immediately followed by a session without feedback (extinction). The CRF schedule resulted in the highest EMG, closely followed by the FR and VR schedules, and the lowest EMG scores were produced by the FI and VI schedules. Similarly, the CRF schedule resulted in the greatest amount of time-above-threshold and the VI and FI schedules produced the lowest time-above-threshold. The highest response rates were generated by the FR schedule, followed by the VR schedule. The CRF schedule produced relatively low response rates, comparable to the rates under the VI and FI schedules. Some of the data are consistent with the partial-reinforcement-extinction effect. The present data suggest that different schedules of feedback should be considered in muscle-strengthening-contexts such as during the rehabilitation of muscles following brain damage or peripheral nervous-system injury.

Adolescent↗
PubMed1983

Dissociating the determinants of self-stimulation.

Four experiments were conducted to elucidate the determinants of the initiation of and escape from electrical stimulation of the lateral hypothalamus under several different reinforcement schedules. The first experiment of this series used correlational and factor analytic techniques to show that, under continuous reinforcement, the vigour of initiation is determined more by forcement than by positive reinforcement. Forcement is defined as all of the performance changes directly elicited and potentiated by the stimulation. Escape is determined by adaptation of positive reinforcement, not by negative reinforcement or aversion. Continuous reinforcement schedules are, therefore, not appropriate for studying either the positive or negative reinforcement produced by brain stimulation. The second experiment used fixed-interval reinforcement schedules to eliminate the effects of forcement on initiation and adaptation of positive reinforcement on escape. Parametric manipulations indicate that activity in the positive reinforcement and escape systems is a simple function of stimulation charge. The combination of parameters which make up a given charge is of relatively little importance. However, the positive reinforcement system becomes maximally activated at far lower charges than does the escape system. The third experiment used a T-maze technique to show that, after 5 sec, anterior hypothalamic stimulation becomes negatively reinforcing, but posterior hypothalamic stimulation does not. Since the escape from posterior hypothalamic stimulation on a fixed-interval schedule can be dissociated from both negative reinforcement and adaptation of positive reinforcement, it is suggested that such escape is reinforced by a positive process triggered by the offset of stimulation (OFF positive reinforcement). The fourth experiment showed that stimulation trains longer than 10 sec are significantly less positively reinforcing than much shorter trains. This reduction in positive reinforcement confirms the development of negative reinforcement in long trains of hypothalamic stimulation, even at posterior electrodes. Negative reinforcement appears to be as general a property of hypothalamic stimulation as is positive reinforcement. Thus, depending on the reinforcement schedule and electrode site, the initiation of lateral hypothalamic stimulation may be determined by ON positive reinforcement, OFF positive reinforcement and forcement. Escape may be determined by OFF positive reinforcement, adaptation of positive reinforcement and negative reinforcement.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Naloxone pretreatment blocks acute morphine-induced sensitization to naltrexone.

The present experiment was designed to examine whether the acute sensitization to naltrexone that is induced by a single dose of morphine could be blocked by pretreatment with naloxone. Food-deprived male Sprague-Dawley rats were trained to respond for food on a multiple-trial fixed interval 3-min schedule. Reinforcement was contingent upon a response within a 10-s limited hold period following a fixed interval of 3 min. A trial consisted of three fixed intervals separated by a 10-min timeout period during which responses were not reinforced. The rate decreasing effects of the opioid antagonist naltrexone were determined by cumulative dosing. Pretreatment with morphine (3.0 mg/kg, SC) resulted in a 70-fold increase in sensitivity to the response rate decreasing effect of naltrexone compared with saline pretreatment. The increased sensitivity was dose-dependently blocked by naloxone administration 10 min before morphine. The blockade by naloxone was overcome by increasing the pretreatment dose of morphine to 10 mg/kg. The results provide further evidence that acute agonist-induced sensitization to the rate-reducing effects of naltrexone is mediated by opioid receptors.

Animals↗
PubMed1999

Animal models of psychopathology: the establishment, maintenance, attenuation, and persistence of head-banging by pigeons.

Investigators of animal models of psychopathology have typically introduced experimental conditions so that an animal's behavior progressively deviates from a baseline of routine laboratory behavior toward a pattern which resembles human psychopathological behavior in some form of S, then R relation. The present experiments report consequential contingency procedures for bringing head-to-wall head-banging by an animal under experimental control and analysis. The first two experiments examined the establishment and maintenance by reinforcement of head-banging by pigeons. The final two experiments examined the occurrence of head-banging, under conditions of extinction and limited reinforcement, when an alternative behavior, i.e., key-pecking, was reinforced under a variety of reinforcement schedules. Extinguished and infrequently reinforced head-banging was found to recur under a variety of conditions including the reinforcement of the more "normal" alternative behavior. To the extent that human patterns are governed by similar functional relations, the data may be of relevance in the analysis of the maintenance, attenuation, and recurrence of human patterns designated as pathological. Further, the permanent elimination of a disturbing pattern may be difficult, and the recurrence of a disturbing pattern might properly be considered a likely and "normal" outcome of basic behavioral processes.

Animals↗
PubMed1969

Effects of reinforcement magnitude on pigeons' preference for different fixed-ratio schedules of reinforcement.

In concurrent, two-member chains, the completion of one or the other of two initial percentage fixed-interval 90-sec links produced a terminal link in which the completion of a fixed ratio produced food reinforcement. The fixed ratios and the duration of reinforcement in the terminal links were varied. Relative response rate in initial links was proportional to the relative reinforcement duration per ratio response (reinforcement duration divided by fixed ratio) in terminal links. The rate of responding in the terminal fixed-ratio links was insensitive to both ratio size and reinforcement duration and therefore did not vary sufficiently to distinguish between responses per reinforcement and immediacy of reinforcement as controlling variables in terminal links.

Journal Article↗
PubMed1974

Pictorial target control of schedule-induced attack in White Carneaux pigeons.

Three pigeons with a history of attacking a mirror target, and two of six pigeons with no prior exposure to targets, attacked a colored photograph of a conspecific during exposure to intermittent schedules of reinforcement for key pecking. Rate of attack on the photograph decreased when the reinforcement schedule was removed. The topography, temporal pattern, and locus of attack on the picture were comparable to schedule-induced attack on live, stuffed, and mirror targets. When silhouette, outline, and plain paper targets were used, schedule-induced attack was more sensitive to a change in target characteristics with a concurrent target-preference procedure than with an analogous successive-testing procedure. The combined results of the two testing procedures indicated that an "upright" white-on-black silhouette of a pigeon with or without an eye was more effective in controlling attack than was a comparable "inverted" silhouette, an outline of a pigeon, or a piece of colored paper.

Journal Article↗
PubMed1976

Conjunctive schedules of reinforcement: III. A fixed-interval adjusting fixed-ratio schedule.

Key pecking of three pigeons was studied under a conjunctive schedule that specified both a fixed-interval and an adjusting fixed-ratio requirement. The fixed-interval schedule was 6 min for one pigeon and 3 min for the other two. The size of the ratio requirement was determined within each cycle of the fixed interval by the duration of the pause before responding began. The fixed-ratio value was at maximum at the start of each fixed interval and decreased linearly until the first response occurred (adjusting fixed-ratio schedule). A peck produced food when the number of responses remaining on the fixed-ratio schedule was completed and when the fixed interval had elapsed. If no response occurred during the interval, the fixed-ratio requirement decreased to one and a single response after the interval elapsed produced food. The initial value of the adjusting fixed-ratio schedule was studied over a range of 0 to 900. Increases in the adjusting fixed-ratio schedule to about 300 responses increased both pause duration and running response rate and also modified the pattern of responding from that obtained under the fixed-interval schedule. Higher values of the adjusting fixed ratio generally decreased pause duration and running response rate and also disrupted responding. Interreinforcement time under the conjunctive schedule was increased substantially when the adjusting fixed-ratio size exceeded 300 responses.

Journal Article↗
PubMed1994

Drug discrimination is a continuous rather than a quantal process following training on a VI-TO schedule of reinforcement.

Debate continues as to whether drug discrimination in animals is an inherently quantal or continuous process. This issue is important in determining the appropriate interpretation of results from drug discrimination studies designed to assess the nature of drug-induced interoceptive cues. The quantal approach holds that subjects perceive a drug cue in an all-or-none manner, while the continuous view proposes that when appropriate training and testing procedures are used, subjects can discriminate along a continuum of interoceptive cues. Data consistent with the quantal view have consistently been generated by animals trained to respond on schedules of reinforcement having an FR component. Since quantal responding is a characteristic of these schedules, results from drug discrimination studies using training schedules with FR components are of little value in empirically determining whether drug discrimination reflects a quantal or continuous process. Use of variable schedules of reinforcement might be more appropriate because the pattern of responding generated does not preclude results consistent with either of the competing views. Data from the following studies that trained subjects using VI schedules with a concurrent TO for incorrect lever responding were analyzed: Barrett et al. (1982): L-5-hydroxytryptophan versus saline; Smith (1990): diazepam versus pentylenetetrazol; Barrett et al. (1992): amphetamine versus haloperidol; Barrett and Steranka (1983): amphetamine versus haloperidol. In every case, when experimental conditions produced a group mean intermediate to that for the training drugs, the distribution of scores for individual animals was normally rather than bimodally distributed.

5-Hydroxytryptophan↗
PubMed1983

Rate-dependent effects of amphetamine on responding under random-interval schedules of reinforcement in the rat.

The parameters of 12 random-interval schedules (cycle length and interreinforcement interval) were varied systematically in order to examine the ability of these schedules to separate the usual relationship between response rate and reinforcement frequency using rats. Response rates varied over a two-fold range for the same frequency of reinforcement under random-interval 30-sec schedules. However, cycle length did not alter response rates significantly at other interreinforcement intervals. Subsequently, the effects of amphetamine on random-interval responding were examined in order to evaluate the roles of control rates of responding and reinforcement in amphetamine's actions. Amphetamine's effects were significantly correlated with both control response rate and control rate of reinforcement. However, by comparison, control response rate was the better predictor of amphetamine behavioral effects. The results support the rate dependency hypothesis that control rate of responding is closely associated with amphetamine's effects on operant behavior.

Animals↗
PubMed1984

Effect of partial reinforcement on tolerance to morphine-induced analgesia and weight loss in the rat.

The effect of partial reinforcement on the development of tolerance to morphine-induced analgesia and weight loss was examined. Groups of rats were presented a distinctive set of environmental cues on several occasions. For one group of rats, morphine (40 mg/kg) was injected each time the cues were presented (morphine--continuous reinforcement). For a second group of rats, morphine was injected only following one of every four cue presentations (morphine--partial reinforcement). Two additional groups were injected with only saline, one on the continuous reinforcement schedule and one on the partial reinforcement schedule. Results demonstrated less tolerance to morphine in the partially reinforced morphine-injected rats than in continuously reinforced morphine-injected rats. Unlike other demonstrations of a tolerance-retarding effect of partial reinforcement, the present results could not have resulted from nonassociative factors related to differential novelty, stress, or practice. Clinical implications for the tolerance-retarding effect of partial reinforcement are discussed.

Animals↗
PubMed1987

The interaction of d-amphetamine and naloxone differs for rats trained on separate fixed-interval or fixed-ratio schedules of reinforcement.

The effects of d-amphetamine and naloxone were investigated using two groups of rats trained on either an FR30 or F12 schedule of reinforcement. Amphetamine (0.1-1.0 mg/kg), and naloxone (1.0 and 10 mg/kg) administered separately reduced responding on the FR procedure in a dose-dependent manner. The combined administration of naloxone with amphetamine had an additive suppressive effect on responding. The same doses of amphetamine and naloxone, when given separately, did not significantly depress responding in the FI procedures. However, naloxone/amphetamine combinations produced a marked inhibition of lever-pressing. Naloxone did not alter the characteristic pattern of responding engendered by amphetamine in this schedule, as measured by the quarter-life and Index of Curvature. It appears that the type of procedure used is a critical factor in demonstrating the effects of naloxone on behavior, and the nature of naloxone/amphetamine interactions.

Animals↗
PubMed1976

Behavior of humans in variable-interval schedules of reinforcement.

During Phase I, human subjects pressed a button for monetary reinforcement in five variable-interval schedules, each of which specified a different frequency of reinforcement. The rate of responding was an increasing, negatively accelerated function of reinforcement frequency; the data conformed closely to Herrnstein's equation. During Phase II, the same five schedules were in operation, but in addition a concurrent variable-interval schedule (B) was introduced, responses on which were always reinforced at the same frequency. Response rate in component A increased while the response rate in B decreased, as a function of the reinforcement frequency in component A. Relative response rates in the two component schedules matched the relative frequencies of reinforcement. Comparing the absolute response rates in component A during Phase I and Phase II it was found that introduction of the concurrent schedule did not affect the value of the theoretical maximum response rate, but did increase the value of the reinforcement frequency needed to obtain any particular submaximal response rate.

Journal Article↗
PubMed1962

FI length and performance of an FI FR chain schedule of reinforcement.

In a chained FI FR schedule, manipulating the length of the FI component produced changes confined almost entirely to the FI performance; increasing the interval length increased the total number of responses emitted per reinforcement. The configuration of the fixed-interval scallop was clearly modified as the interval length was increased, with the larger intervals becoming flatter (i.e., a larger proportion of the total responses earlier in an interval). Measurement of the postreinforcement pause is suggested as a possible indicator of fixed-interval scalloping.

Learning↗
PubMed2006

Self-administration of heroin, cocaine and their combination under a discrete trial schedule of reinforcement in rats.

Several self-administration models have been used to study the interactions between cocaine and heroin, and the schedule of reinforcement used is an important consideration for these studies. Behavior maintained by cocaine, heroin or their combination was studied using a discrete trial schedule that has been described for cocaine self-administration previously. This schedule permits 24 h access to drug without mortality associated with unlimited access to cocaine, and provides unique measures related to the circadian pattern of drug self-administration. Cocaine and heroin combined maintained higher rates of responding compared to either drug alone when a maximum of three infusions were available each hour (DT3), and decreased food intake compared to cocaine alone. There were significantly greater numbers of hours in both the light and dark cycles during which animals self-administered heroin or the combination of cocaine/heroin compared to cocaine alone. When the FR was increased to 4 under the DT3 access conditions, responding maintained by cocaine or heroin extinguished to levels not different than those maintained by saline while food reinforcement remained intact. The combination of cocaine and heroin maintained robust responding under these conditions. This schedule of reinforcement appears to elucidate behavioral interactions between cocaine and heroin that are more complex than rate of drug consumption and may provide a procedure to address some of the issues related to co-abuse of these drugs.

Animals↗
PubMed1978

Pentobarbital, promazine, d-amphetamine, and scopolamine effects on behavior under multiple and primed schedules of reinforcement.

Pigeons responded under compound fixed-interval (FI) fixed-ratio (FR) schedules of food presentation. Distinctive discrimininative stimuli were either continuously present during each component schedule (multiple FI FR) or were present only for a brief period at the beginning of each component (primed FI FR). Similar rates and patterns of responding were maintained under the multiple and primed schedules. Pentobarbital, scopolamine, and d-amphetamine decreased FR responding, but promazine had little effect at the doses studied. d-Amphetamine and promazine increased FI responding at certain doses, pentobarbital had little effect, and scopolamine decreased responding. There were no systematic differences in the effects of drugs under the multiple and primed schedules, in spite of the differences in discriminative stimuli under the conditions.

Animals↗
PubMed1999

Effect of central 5-hydroxytryptamine depletion on changeover behaviour in concurrent schedules of reinforcement.

RATIONALE: Previous experiments have shown that rats whose 5-hydroxytryptaminergic (5-HTergic) pathways have been destroyed exhibit higher rates of switching between response alternatives on various temporal differentiation schedules. OBJECTIVE: This paper reports two experiments investigating the effect of central 5-HT depletion on switching between concurrent schedules of reinforcement which do not entail temporal differentiation of behaviour. METHODS: Rats received injections of 5,7-dihydroxytryptamine into the dorsal and median raphe nuclei or sham lesions. They were trained to press levers for sucrose reinforcement. In experiment 1, the rats were exposed to concurrent pairs of variable-time (VT) schedules specifying equal inter-reinforcement intervals; responses on a single "changeover lever" alternated between the two VT schedules. In experiment 2, the rats were exposed to concurrent pairs of variable-interval (VI) schedules specifying equal inter-reinforcement intervals; responses on one lever ("VI lever") earned reinforcers, while responses on the other lever ("changeover lever") alternated between the two VI schedules. RESULTS: In experiment 1, both groups showed longer "dwell-times" (intervals between successive changeover responses) when a reinforcer was delivered in the "dwell" than when no reinforcer was delivered ("win-stay" effect). The lesioned rats showed higher rates of changeover responding and shorter dwell-times (with and without reinforcer delivery) than the sham-lesioned group. In experiment 2, the rate of responding on the VI lever did not differ significantly between the two groups; however, the lesioned rats showed higher rates of changeover responding, shorter dwell-times (with and without reinforcer delivery) and smaller numbers of inter-changeover responses on the VI lever than the sham-lesioned group. In both experiments, the levels of 5-HT and 5-hydroxyindoleacetic acid were reduced in the brains of the lesioned rats, but the levels of noradrenaline and dopamine were not altered. CONCLUSIONS: These results provide further evidence for the involvement of the ascending 5-HTergic pathways in behavioural "switching", and indicate that this is not restricted to temporal differentiation schedules.

Animals↗
PubMed1980

A comparison of the effects of fixed and variable ratio schedules of reinforcement on the behavior of deaf children.

The performance of all five students in an adjustment class for deaf children was compared under fixed and variable ratio schedules of reinforcement. During the fixed ratio (FR) condition, students earned checks if they were attentive and did not engage in disruptive behavior. These checks could be exchanged for the opportunity to draw a prize from a grab bag. During the variable ratio (VR) condition, they earned a draw from the grab bag according to a variable ratio schedule with a mean ratio equal to the value of the preceding FR schedule. During the VR condition, students visually attended more and engaged in disruptive behavior less often than during the FR condition. The number of math problems completed per minute was also higher during the VR condition although no specific consequences were applied to math performance.

Attention↗