scholarly journals The probability of reinforcement per trial affects post-trial responding and subsequent extinction, but not within-trial responding

2020 ◽  
Author(s):  
Justin Harris ◽  
Dorothy Kwok
Keyword(s):  
Conditioned Stimulus ◽  
Response Rates ◽  
Reinforcement Rate ◽  
Trial Probability ◽  
Post Trial ◽  
Conditioned Responding

During magazine approach conditioning, rats do not discriminate between a conditioned stimulus (CS) that is consistently reinforced with food and a CS that is occasionally (partially) reinforced, as long as the CSs have the same overall reinforcement rate per second. This implies that rats are indifferent to the probability of reinforcement per trial. However, in the same rats, the per-trial reinforcement rate will affect subsequent extinction—responding extinguishes more rapidly for a CS that was consistently reinforced than for a partially reinforced CS. Here, we trained rats with consistently and partially reinforced CSs that were matched for overall reinforcement rate per second. We measured conditioned responding both during and immediately after the CSs. Differences in the per-trial probability of reinforcement did not affect the acquisition of responding during the CS, but did affect subsequent extinction of that responding, and also affected the post-CS response rates during conditioning. Indeed, CSs with the same probability of reinforcement per trial evoked the same amount of post-CS responding even when they differed in overall reinforcement rate and thus evoked different amounts of responding during the CS. We conclude that reinforcement rate per second controls rats’ acquisition of responding during the CS, but at the same time rats also learn specifically about the probability of reinforcement per trial. The latter learning affects the rats’ expectation of reinforcement as an outcome of the trial, which influences their ability to detect retrospectively that an opportunity for reinforcement was missed, and in turn drives extinction.

scholarly journals The Partial Reinforcement Extinction Effect Depends on Learning about Non-Reinforced Trials Rather than Reinforcement Rate

2020 ◽  
Author(s):  
Justin Harris ◽  
Dorothy Kwok ◽  
Daniel Gottlieb
Keyword(s):  
Alternative Explanation ◽  
Food Pellet ◽  
Reinforcement Rate ◽  
Partial Reinforcement ◽  
The Other ◽  
Partial Reinforcement Extinction Effect ◽  
Consistent Reinforcement ◽  
Trial Probability ◽  
The Difference ◽  
Conditioned Responding

Conditioned responding extinguishes more slowly after partial (inconsistent) reinforcement than after consistent reinforcement. This Partial Reinforcement Extinction Effect (PREE) is usually attributed to learning about nonreinforcement during the partial schedule. An alternative explanation attributes it to any difference in the rate of reinforcement, arguing that animals can detect the change to nonreinforcement more quickly after a denser schedule than a leaner schedule. Experiments 1a and 1b compared extinction of magazine responding to a conditioned stimulus (CS) reinforced with one food pellet per trial and a CS reinforced with two pellets per trial. Despite the difference in reinforcement rate, there was no reliable difference in extinction. Both experiments did demonstrate the conventional PREE comparing a partial CS (50% reinforced) with a consistent CS. Experiments 2 and 3 tested whether the PREE depends specifically on learning about nonreinforced trials during partial reinforcement. Rats were trained with two CS configurations, A and AX. One was partially reinforced, the other consistently reinforced. When AX was partial and A consistent, responding to AX extinguished more slowly than to A. When AX was consistent and A was partial, there was no difference in their extinction. Therefore, pairing X with partial reinforcement allowed rats to show a PREE to AX that did not generalise to A. Pairing A with partial reinforcement meant that rats showed a PREE to A that generalised to AX. Thus, the PREE depends on learning about nonreinforced trials during partial reinforcement and is not due to any difference in per-trial probability of reinforcement

scholarly journals Supergalactic Structure of Multiplets with the Telescope Array Surface Detector

2019 ◽  
Vol 210 ◽  
pp. 01006 ◽  
Author(s):  
Jon Paul Lundquist ◽  
Pierre V. Sokolsky
Keyword(s):  
Magnetic Fields ◽  
Spherical Surface ◽  
High Energy ◽  
Ultra High Energy ◽  
Telescope Array ◽  
High Energy Cosmic Rays ◽  
Surface Detector ◽  
Trial Probability ◽  
Post Trial ◽  
Event Energy

Evidence of supergalactic structure of multiplets has been found for ultra-high energy cosmic rays (UHECR) with energies above 1019 eV using 7 years of data from the Telescope Array (TA) surface detector. The tested hypothesis is that UHECR sources, and intervening magnetic fields, may be correlated with the supergalactic plane, as it is a fit to the average matter density within the GZK horizon. This structure is measured by the average behavior of the strength of intermediate-scale correlations between event energy and position (multiplets). These multiplets are measured in wedge-like shapes on the spherical surface of the fieldof-view to account for uniform and random magnetic fields. The evident structure found is consistent with toy-model simulations of a supergalactic magnetic sheet and the previously published Hot/Coldspot results of TA. The post-trial probability of this feature appearing by chance, on an isotropic sky, is found by Monte Carlo simulation to be ~4.5σ.

Differential Acquisition, Extinction, and Reinstatement of Conditioned Suppression in Mice

2007 ◽  
Vol 60 (10) ◽  
pp. 1313-1320 ◽  
Author(s):  
Trinette Dirikx ◽  
Tom Beckers ◽  
Clara Muyls ◽  
Paul Eelen ◽  
Debora Vansteenwegen ◽  
...  
Keyword(s):  
Conditioned Stimulus ◽  
Unconditioned Stimulus ◽  
Conditioned Suppression ◽  
Conditioned Fear ◽  
The Other ◽  
Control Group ◽  
Selective Suppression ◽  
Differential Acquisition ◽  
Group A ◽  
Conditioned Responding

In animals, the reappearance of conditioned fear responses after extinction has been primarily investigated using single-cue conditioning paradigms. However, a differential paradigm can overcome several of the disadvantages associated with a single-cue procedure. In the present study, the reinstatement phenomenon was assessed in mice using a differential conditioned suppression paradigm. In a first phase, one conditioned stimulus (CS +) was consistently paired with an unconditioned stimulus (US; footshock) while another CS (CS–) was not, resulting in selective suppression of previously trained instrumental behaviour during the CS +. After the extinction phase, half of the animals (reinstatement group) were presented with unsignalled USs, while the other half were not (control group). A differential return of conditioned responding was observed in the reinstatement group, but not in the control group. The implications of these findings for future conditioning research are discussed.

scholarly journals Cue duration determines response rate but not rate of acquisition of Pavlovian conditioning in mice

2020 ◽  
Vol 73 (11) ◽  
pp. 2026-2035
Author(s):  
Joseph M Austen ◽  
David J Sanderson
Keyword(s):  
Pavlovian Conditioning ◽  
Response Rate ◽  
Reinforcement Rate ◽  
Estimation Theory ◽  
Cumulative Exposure ◽  
Rate Estimation ◽  
Conditioning Rate ◽  
The Difference ◽  
Conditioned Responding ◽  
Associative Analysis

The duration of a conditioned stimulus (CS) is a key determinant of Pavlovian conditioning. Rate estimation theory (RET) proposes that reinforcement rate is calculated over cumulative exposure to a cue and the reinforcement rate of a cue, relative to the background reinforcement rate, determines the speed of acquisition of conditioned responding. Consequently, RET predicts that shorter-duration cues require fewer trials to acquisition than longer-duration cues due to the difference in reinforcement rates. We tested this prediction by reanalysing the results of a previously published experiment. Mice received appetitive Pavlovian conditioning of magazine approach behaviour with a 10-s CS and a 40-s CS. Cue duration did not affect the rate at which responding emerged or the rate at which it peaked. The 10-s CS did elicit higher levels of responding than the 40-s CS. These results are not consistent with rate estimation theory. Instead, they are consistent with an associative analysis that assumes that asymptotic levels of responding reflect the balance between increments and decrements in associative strength across cumulative exposure to a cue.

scholarly journals WITHIN-SESSION RESPONSE RATES WHEN REINFORCEMENT RATE IS CHANGED WITHIN EACH SESSION

1995 ◽  
Vol 64 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Frances K. McSweeney ◽  
Jeffrey N. Weatherly ◽  
Samantha Swindell
Keyword(s):  
Response Rates ◽  
Reinforcement Rate

Prevention of the degraded-contingency effect by signalling training trials

2000 ◽  
Vol 53 (2b) ◽  
pp. 97-119 ◽  
Author(s):  
Lisa M. Gunther ◽  
Ralph R. Miller
Keyword(s):  
Conditioned Stimulus ◽  
Underlying Mechanism ◽  
Excitatory Conditioning ◽  
Retrospective Revaluation ◽  
Target Conditioned Stimulus ◽  
Stimulus Effect ◽  
Conditioned Responding ◽  
Effect Experiment ◽  
Contingency Effect

Presentation of unsignalled unconditioned stimuli (USs) interspersed among Pavlovian excitatory conditioning trials weakens conditioned responding to a target conditioned stimulus (CS; Rescorla, 1968). However, signalling these intertrial USs with another cue (a cover stimulus) has been shown to alleviate this degraded-contingency effect (e.g. Durlach, 1982, 1983). In contrast to signalling the inter-trial USs, the present experiments examined the effect on the degraded-contingency effect of signalling the target CS-US pairings. Experiment 1, using parameters selected to avoid overshadowing, found that consistently presenting a cover stimulus immediately prior to the target CS-US pairings during degraded-contingency training alleviated the degraded-contingency effect. Experiment 2 examined the underlying mechanism responsible for this cover-stimulus effect through posttraining associative inflation of the cover stimulus or the context, and found that inflation of the cover stimulus attenuated responding to the target CS (i.e. empirical retrospective revaluation). The results are discussed in terms of various acquisition- and expression-focused models of acquired responding.

scholarly journals The Partial-Reinforcement Extinction Effect Does Not Result from Reduced Sensitivity to Non-Reinforcement

2020 ◽  
Author(s):  
Justin Harris ◽  
Manuel Stephen Seet ◽  
Dorothy Kwok
Keyword(s):  
Conditioned Stimulus ◽  
Reinforcement Schedule ◽  
Conditioned Inhibition ◽  
Reinforcement Rate ◽  
Partial Reinforcement ◽  
The Other ◽  
Partial Reinforcement Extinction Effect

Five experiments used a magazine approach paradigm with rats to investigate whether learning about non-reinforcement is impaired in the presence of a conditioned stimulus (CS) that had been partially reinforced (PRf). Experiment 1 trained rats with a PRf CS and a continuously reinforced (CRf) CS, then extinguished responding to both CSs presented together as a compound. Probe trials of each CS presented alone revealed that extinction was slower for the PRf CS than the CRf CS, despite being extinguished in compound. In Experiment 2, a CRf light was extinguished in compound with either a CRf CS or a PRf CS that had been matched for overall reinforcement rate. Responding to the light extinguished at the same rate regardless of the reinforcement schedule of the other CS. Experiment 3 replicated this result with a PRf light. Thus, we found no evidence that a PRf CS impairs extinction of another CS presented at the same time. Experiments 4 and 5 extended this approach to study the acquisition of conditioned inhibition by training an inhibitor in compound with either a PRf or CRf excitatory CS. The reinforcement schedule of the excitatory CS had no effect on the acquisition of inhibition. In sum, conditioning with a PRf schedule slows subsequent extinction of that CS but does not affect learning about the non-reinforcement of other stimuli presented at the same time. We conclude that the Partial Reinforcement Extinction Effect is not due to a decrease in sensitivity to non-reinforcement following presentation of a PRf CS.

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