PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Reinforcement learning”

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 559 records · Page 31Linked to original sources
PubMed2003

Operant learning and differential-reinforcement-of-low-rate 36-s responding in 5-HT1A and 5-HT1B receptor knockout mice.

Previous studies with mice lacking 5-HT(1A) (1AKO) and 5-HT(1B) (1BKO) receptors in hippocampus-dependent learning and memory paradigms, suggest that these receptors play an important role in learning and memory, although their precise role is unclear. In the present study, 1AKO and 1BKO mice were studied in operant behavioural paradigms of decision making and response inhibition, to further study the putative involvement of these receptors in prefrontal cortex-dependent learning and memory. Moreover, because 1AKO mice have been shown to exhibit an antidepressant-like phenotype and 1BKO mice to be more impulsive in ethological studies, mice were trained in a differential-reinforcement-of-low-rates (DRL) procedure. Overall, results indicate that 1AKO and 1BKO mice display subtle differences in operant paradigms of decision making and response inhibition compared to wild type (WT) mice. In addition, when responding under a DRL 36-s schedule had stabilised, 1BKO mice showed a phenotype indicative of increased impulsivity, whereas 1AKO mice did not differ from WT mice. In conclusion, 5-HT(1B) receptors appear to play an important role in impulsivity and a minor role in prefrontal cortex-dependent learning and memory as shown by the results obtained in serial reversal learning and extinction. In contrast, 5-HT(1A) receptors appear to be involved in facilitation of autoshaping, but their role in impulsivity and prefrontal cortex-dependent learning and memory appears to be limited.

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↗
PubMed1984

Learned helplessness: effects of noncontingent reinforcement and response cost with emotionally disturbed children.

In order to investigate the effectiveness of noncontingent reinforcement and response cost in inducing learned helplessness and to determine whether depressed Ss respond differently than nondepressed Ss, 28 emotionally disturbed children (20 boys, 8 girls) were tested in a modified learned helplessness paradigm. Children's Depression Inventory score and diagnosis were each used to distinguish "depressed" and "nondepressed" children. Half of the depressed group and half of the nondepressed group received noncontingent response cost, the other half of the two groups received noncontingent positive reinforcement. Results indicated that both noncontingent response cost and noncontingent reinforcement led to reduced persistence time relative to persistence under conditions of contingent reinforcement. There was only one significant difference between depressed and nondepressed Ss (differential persistence time over trials) and there were no significant interactions. Results were discussed in terms of Seligman's formulation of learned helplessness and the extension of this model to a clinical child population.

Achievement↗
PubMedDate not supplied

Motivation and reinforcement in the systemic mechanisms of behavior: dynamic reinforcement engrams.

Materials are presented which suggest the interaction of motivation and reinforcement in the systemic organization of behavioral acts in individual brain neurons. It was demonstrated that immune mechanisms participate in the interaction of motivation and reinforcement. It is postulated that reinforcement during learning, by means of backward afferentation, forms molecular reinforcement engrams in the neuronal structures of the action outcome acceptor. The molecular reinforcement engrams are built by processes of the synthesis of DNA and protein molecules in ribosomes. These engrams, during the succeeding appearances of the corresponding needs, are activated by the dominant motivation and in anticipation direct animals toward the satisfaction of their initial needs.

Animals↗
PubMedDate not supplied

Predictive regulation of associative learning in a neural network by reinforcement and attentive feedback.

At least four types of learning processes are relevant in the present paper: learning of conditioned reinforcement, incentive motivation, sensory expectancy, and motor command. These several types of learning processes, which operate on a slow time scale, regulate and are regulated by rapidly fluctuating limited capacity STM representations of sensory events. The theory suggest how nonlinear feedback interactions among these fast information processing mechanisms and slow learning mechanisms participate in different conditioning paradigms, and actively regulate learning and memory to generate predictive internal representations of external environmental contingencies.

Animals↗
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↗