Partial Reinforcement Research Articles

Partial reinforcement extinction and omission effects in the elimination and recovery of discriminated operant behavior.

Three experiments explored how training reinforcement schedules and context influence the elimination and recovery of human operant behavior. In Experiment 1, participants learned a discriminated operant response in Context A before the response was eliminated with extinction in Context B. They then received a final test in each context. Groups were trained with a discriminative stimulus that predicted a reinforced response on either every trial (continuous reinforcement [CRF]) or some of the trials (partial reinforcement [PRF]). Extinction was slower following PRF training (a partial reinforcement extinction effect [PREE]) and extinguished responding increased when tested in Context A ("ABA" renewal). Experiment 2 further confirmed the PREE was obtained equally whether extinction occurred in the training context (Context A) or a new context (Context B) which is consistent with trial-based accounts of the PREE. Experiment 3 used the same design as Experiment 1 to evaluate the influence of training reinforcement on response elimination with an omission contingency. Across the omission training phase in Context B, the decrease in responding occurred more slowly in the PRF-trained group in comparison to the CRF-trained group, perhaps the first demonstration of what might be termed a PRF omission effect. Again, ABA renewal was observed in Context A. Training reinforcement schedule therefore had a similar influence on response elimination with extinction and omission. Elimination and recovery of human instrumental behavior, with extinction or omission, are influenced by training reinforcement schedule and context. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A viable strategy to recycle post-used carbon fiber thermoset composites as a multi-functional filler for PP composites

The correct destination of this post-used of carbon fiber (CF) reinforced epoxy composites, is considered noble since their manufacturing process involves high costs and advanced technologies. This work aimed to study the feasibility of mechanical recycling of CF/epoxy composites for nobler applications, such as non-structural internal components, antistatic packaging, or electronics housings. The CF/epoxy residues (CFRPres.) were collected from parts of the aerospace industry, selected, and ground, followed by granulometric separation. Then, the CFRPres. particles were incorporated as filler and/or partial reinforcement in a polypropylene (PP) matrix to obtain a new thermoplastic composite using double-screw extrusion processing, followed by hot compression molding to obtain standardized specimens. The quality of the composites obtained was evaluated through mechanical tests (tensile test, Izod impact strength, and Shore D hardness), thermal (differential scanning calorimetry), electric (impedance spectroscopy, electromagnetic), and morphological characterization (scanning electron microscopy). The addition of 30 wt% of CFRPres. in the PP matrix increases the electrical conductivity by seven orders of magnitude and exhibits semiconductor behavior, and increases 168% in the elastic modulus. As for the electromagnetic properties, increasing the content of residues in the composites also occurs a substantial increase in the relative permittivity. In addition, the development of composites from the incorporation of residues from the aerospace sector proved viable in applications where the impact strength, rigidity, and hardness are crucial, even for the high content of residues aggregate.

Evidence for Different Roles of Inhibitory and Prospective Intolerance of Uncertainty During Threat Discrimination Learning

Uncertainty is a core component of threat and associated learning processes. One methodological factor impacting uncertainty in threat learning paradigms is the threat reinforcement rate, which refers to the proportion of times a cue is reinforced with an aversive stimulus. This study tested the effect of partial vs continuous threat reinforcement on threat / safety discrimination learning, as indexed by skin conductance response (SCR). Using a within-participants design, fifty-nine participants completed a task in which three colored shapes were paired with electric shock at reinforcement schedules of 100% (CS+), 50% (CS+) and 0% (CS-). In addition, the study examined the relationship between the Intolerance of Uncertainty scale (IU) and two subscales – inhibitory and prospective IU – with threat discrimination learning. The data show heightened SCR in the continuous vs partial reinforcement condition to all stimuli, but limited evidence of enhanced discrimination learning. Furthermore, no association was observed between total IU score and threat-safety discrimination. However, using a two-factor model of IU, findings showed higher inhibitory IU and higher prospective IU were associated with diminished and heightened threat discrimination, respectively. These results contribute to a fast-growing literature exploring how the uncertainty inherent to predictors of threat, individual differences in sensitivity to uncertainty, and interactions between these two factors, can shape the acquisition of threat memory.

Instrumental learning and behavioral persistence in children with attention-deficit/hyperactivity-disorder: does reinforcement frequency matter?

Prominent theoretical accounts of attention-deficit/hyperactivity-disorder (ADHD) hypothesize that reinforcement learning deficits underlie symptoms of ADHD. The Dynamic Developmental Theory and the Dopamine Transfer Deficit hypothesis assume impairments in both the acquisition and extinction of behavior, especially when learning occurs under partial (non-continuous) reinforcement, and subsequently the Partial Reinforcement Extinction Effect (PREE). Few studies have evaluated instrumental learning in ADHD and the results are inconsistent. The current study investigates instrumental learning under partial and continuous reinforcement schedules and subsequent behavioral persistence when reinforcement is withheld (extinction) in children with and without ADHD. Large well-defined samples of children with ADHD (n = 93) and typically developing (TD) children (n = 73) completed a simple instrumental learning task. The children completed acquisition under continuous (100%) or partial (20%) reinforcement, followed by a 4-min extinction phase. Two-way (diagnosis by condition) ANOVAs evaluated responses needed to reach the learning criterion during acquisition, and target and total responses during extinction. Children with ADHD required more trials to reach criterion compared to TD children under both continuous and partial reinforcement. After partial reinforcement, children with ADHD executed fewer target responses during extinction than TD children. Children with ADHD executed more responses than TD children during extinction, irrespective of learning condition. The findings demonstrate general difficulties in instrumental learning in ADHD, that is, slower learning irrespective of reinforcement schedule. They also show faster extinction following learning under partial reinforcement in those with ADHD, that is, a diminished PREE. Children with ADHD executed more responses during extinction. Results are theoretically important, with clinical implications for understanding and managing learning difficulties in those with ADHD, as they suggest poorer reinforcement learning and lower behavioral persistence.

Hydronic flow path analysis on the thermal comfort performance of radiant cooling system

Construction and operation in the building sector account for more than 1/5th of global energy consumption. Moving on to an energy-efficient cooling technology and eco-friendly building material can lead to energy savings and a reduction in associated CO2 emissions. In the present study, an energy-efficient thermally activated building system (TABS) is integrated with eco-friendly building material, namely, glass fibre reinforced gypsum (GFRG). The proposed hybrid system is termed as thermally activated glass fibre reinforced gypsum (TAGFRG) system. This system is not only energy-efficient and eco-friendly but also provides better thermal comfort. An experimental room is constructed with the TAGFRG roof within the Indian Institute of Technology Madras campus, Chennai, i.e., in a tropical warm and humid climate zone. The TAGFRG roof has reinforcement in every third cavity with cooling pipes, while in the other two cavities, cooling pipes are embedded with air gap and partial reinforcement. The TAGFRG roof has four parallel loops of cooling pipelines, and each loop consists of one reinforcement zone (RZ) and two air gap zones (AZ1 and AZ2) in series. According to the water flow path in a single loop, various combinations of the flow path, i.e., RZ → AZ1 → AZ2, AZ1 → RZ → AZ2 and AZ1 → AZ2 → RZ, have been analyzed. According to the adaptive thermal comfort model, the water flow path has a negligible effect on thermal comfort. The average operative temperature for all the cases investigated varies between 28.1 and 29.2 °C. The operative temperature is always within the 90% band of thermal comfort, as per the adaptive comfort model.

Supplemental Material for Partial Reinforcement Extinction and Omission Effects in the Elimination and Recovery of Discriminated Operant Behavior

Supplemental Material for Partial Reinforcement Extinction and Omission Effects in the Elimination and Recovery of Discriminated Operant Behavior

Delaying extinction weakens the partial reinforcement extinction effect.

Conditioned responding that has been extinguished can spontaneously return when the conditioned stimulus (CS) is first presented after an extended delay. This spontaneous recovery of responding suggests that the memory of nonreinforced experience with the CS is impaired over the delay period. Rescorla (2007) provided evidence that this effect of time on nonreinforcement is not specific to extinction. He showed that a delay period can also reverse the reduction of responding established by a partial reinforcement schedule. Here we describe a series of experiments that attempted to confirm Rescorla's finding and additionally assessed the impact of the delay on another well-known consequence of partial reinforcement-the partial reinforcement extinction effect (PREE). Like Rescorla, we used a Pavlovian conditioning procedure with rats, measuring magazine activity during a CS that signaled food. Unlike Rescorla, we did not find that responding acquired under partial reinforcement spontaneously increased after a delay; however, we did observe a significant reduction in the PREE after that delay. We conclude that the passage of time has a selective effect on the retrieval of memories of nonreinforcement. Therefore, time produces spontaneous recovery by impairing retrieval of extinction memories but also weakens the PREE by impairing retrieval of memories of nonreinforcement that were acquired during partial reinforcement. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Limit analysis of locally reinforced masonry arches

The use of composite on the strengthening and retrofitting of masonry structures over the past few decades has gained considerable importance. In this paper, the influence of partial reinforcement on the structural response of masonry arches is studied. An upper bound limit analysis numerical approach has been implemented to compute the collapse multipliers and reproduce the collapse mechanisms of two different study cases by increasing the cohesion value of the reinforced inter-block joints. The results thus obtained, have been compared to numerical simulation outcomes reported by other authors on the literature. The numerical approach adopted on this work, which requires few input parameters, is relatively fast in comparison to alternative numerical simulation methods, provided good agreement in terms of collapse loads and mechanisms.

Some detrimental effects of conditioned reinforcement on the maintenance of dog behavior.

In animal training, there is disagreement regarding whether a conditioned reinforcer, such as the sound of a clicker, should always be followed by an unconditioned reinforcer, such as a treat. Proponents for clicking without always giving a treat argue that the click can substitute for the reinforcer, due to Pavlovian conditioning and the partial reinforcement effect. Those who advise always following the click with a treat argue that the clicker will become an unreliable predictor of food if it is not always followed by an unconditioned reinforcer. In this study, a within-subject reversal design with two dogs was used to compare the behavioral effects of always following a click with food (one click condition) and only sometimes following a click with food (two clicks condition). Results showed that the two clicks condition disrupted the frequency, accuracy, and topography of the behavior and increased noncompliance and other unwanted behaviors. While the detrimental effects of this condition may seem paradoxical at first, they can be explained by the discriminative properties of the conditioned reinforcer.

More engagement in inefficient avoidance through partial reinforcement

Background and objectivesIn anxiety-related disorders, excessive avoidance often coexists with an impaired sense of control over external threats. In contrast, lab studies have shown that avoidance responding increase with higher objective controllability over threat, accompanied with more confidence in the effectiveness of the avoidance response. One reason for this divergence could be that those lab studies are overly simplistic with a single, avoidable threat. MethodsWe conducted an experiment that additionally included a completely uncontrollable threat, and we manipulated the reinforcement rate of the avoidance response to the (semi-)controllable threat (75% versus 100%). ResultsThe 100% group showed increased avoidance to the controllable threat and decreased avoidance to the unavoidable threat over learning. Interestingly, compared to the 100% group, the 75% group displayed less confidence in their avoidance to the controllable threat and they avoided the uncontrollable threat more often. LimitationsOnly two reinforcement rates of effective avoidance were included, which may limit the generalizability of the current findings. Perceived control was not directly measured. ConclusionsLower reinforcement rates create ambiguity between effective and ineffective situations of avoidance, which engenders generalization of unpredictability from effective to ineffective situation, thereby driving up ineffective avoidance rates. Partially reinforced effective avoidance responses and elevated ineffective avoidance responses together lead to more exposure to uncontrollable threat, weakening the sense of control over the threat, which could further increase avoidance behaviors. Controllability is often overlooked in avoidance research but can be key to understanding the development of maladaptive avoidance behaviors.

0675 Vagal Activity in REM Sleep Is Associated With Extinction Recall in Trauma Exposed Individuals but Not in Individuals With Post-Traumatic Stress Disorder

Abstract Introduction Post-traumatic stress disorder (PTSD) is characterized by impaired fear extinction memory. Sleep, and especially REM sleep, facilitates consolidation of fear extinction. Therefore, it is postulated that abnormal sleep physiology in PTSD may contribute to its persistence. Recent studies suggest that vagal activity may support the memory benefit of sleep. In addition, a separate line of studies shows reduced vagal activity during sleep in PTSD. However, the link between extinction memory and vagal activity during sleep has not been investigated in PTSD. We examined the association of extinction recall with vagal activity, measured as heart rate variability (HRV), during REM sleep, in PTSD and matched controls. Methods Participants included individuals with PTSD (n=70) and trauma exposed controls (TEC; n=69). All participants completed 3 nights of ambulatory polysomnography that included ECG. After acclimation and baseline PSG nights, fear conditioning and extinction learning were carried out in the evening after which they completed a third ("consolidation") PSG night. Extinction recall was tested 24h later. During fear conditioning, partial reinforcement with a mild electric shock produced a conditioned skin conductance response (SCR) to the image of a colored lamp, which was immediately extinguished by un-reinforced presentations in a different room. Extinction recall was indexed by the degree to which SCR remained suppressed 24h later. HRV indices were calculated using Kubios software. Results Preliminary analyses included 20 individuals with PTSD and 37 TEC participants. In the TEC group, extinction recall was significantly correlated with REM sleep HRV measures that reflect vagal activity, including high frequency (HF) absolute power (Rs=0.51, p =0.009), HF normalized units (Rs=0.54, p =0.005) and RMSSD (Rs=0.40, p =0.046). In hierarchical regression models which included extinction recall as the dependent variable, HF absolute power accounted for a significant proportion of the variance, over and above a model that included %REM sleep, %N3 sleep, REM density and average duration of REM epochs (R2=0.50, F=5.06, p=0.04). These associations were not present in the PTSD group Conclusion Our preliminary results suggest that vagal activity during REM sleep is involved in the consolidation of extinction memory and that this mechanism may be impaired in PTSD. Support (If Any) R01MH109638 K23MH119322

Partial reinforcement effects on acquisition and extinction of a conditioned taste aversion.

Four experiments with rat subjects asked whether a partial reinforcement extinction effect (PREE) occurs in taste aversion learning. The question has received little attention in the literature, and to our knowledge no taste aversion experiment has previously demonstrated a PREE. In each of the present experiments, experimental groups received a taste mixed in drinking water for 20 min; such taste exposures were sometimes paired with a lithium chloride (LiCl) injection and sometimes not. Control groups received only taste-LiCl pairings. There was evidence that each reinforced and non-reinforced trial produced increments and decrements in aversion strength (respectively), and trials mattered more than accumulated time during the conditioned stimulus and during the background (as emphasized in time-accumulation models like those of Gallistel and Gibbon, Psychological Review, 107, 289-344, 2000, and Gibbon and Balsam, Autoshaping and conditioning theory, Academic Press, New York, pp. 219-235, 1981). In addition, a partial reinforcement extinction effect was observed when there was a relatively large number of conditioning trials. The results extend our understanding of extinction in taste aversion learning and provide more evidence that aversion learning might follow rules that are qualitatively similar to those of other forms of learning.

The effect of partial and continuous reinforcement on the generalization of conditioned fear in humans

The popular paradigm of Pavlovian conditioned fear has been used to study learning and memory processes that mediate anxiety disorder. Fear extinction studies have often paired the conditioned stimulus (CS) and the unconditioned stimulus (US) on a subset of acquisition trials (partial reinforcement) to prolong extinction. However, there have been few studies on the effect of partial reinforcement and continuous reinforcement on fear generalization. To better understand the influence of the CS–US pairing rate on fear generalization, the experimenters used CSs paired with US at 50% (CS50), 75% (CS75), and 100% (CS100) during fear conditioning. A total of 66 participants, who were assigned at random to the different reinforcement rates, underwent fear acquisition and generalization tests on expectancy ratings and skin conductance responses. The continuous reinforcement group (CS100) showed a flatter generalization gradient, while the partial reinforcement groups (CS50, CS75) showed increased generalization magnitudes. These results suggest that the partial reinforcement extinction effect is related to threat intensity, whereas continuous reinforcement produces threat-sensitivity fear generalization, which has been used to explain the overgeneralization of fear.

The relationship between Intolerance of Uncertainty and conditioned fear acquisition: Evidence from a large sample

Despite being considered a valid model for the etiology of anxiety disorders, the fear conditioning paradigm does not always show clear correlations with anxious personality traits that constitute risk factors for the development of anxiety disorders. This may in part due to error variance and the fact that fear conditioning studies are typically underpowered to investigate inter-individual differences. In the current study, we focus on the relationship between conditioned fear acquisition and Intolerance of Uncertainty (IU). In a re-analysis of a large previous study (N = 120), which was conducted using a healthy student sample and a partial reinforcement procedure (75%) with words as Conditioned Stimuli (CSs), the relationship between IU and several outcome measures (i.e., fear ratings, expectancy ratings, skin conductance responses, and startle responses) during fear acquisition was examined. We find that IU is positively related to fear ratings towards the CS+ (r = 0.29), even when controlling for the shared variance with trait anxiety. Furthermore, we find a subtle relationship between IU and startle responses to the CS− (r = −0.23), though this correlation did not survive correction for the shared variance with trait anxiety. Taken together, we replicate some of the correlations previously reported in the literature. However, we recommend that future studies employ even larger samples and more advanced statistical techniques such as structural equation modelling to investigate the correlations between fear acquisition indices and anxious traits in a fine-grained manner.

Toughening mechanisms and morphology of composite cylinders interleaved with hybrid nanoparticles

Laminated carbon fiber-reinforced plastics (CFRPs) have been applied to complex structures in various industries owing to their excellent physical and mechanical properties. However, the use of such plastics is limited because their through-thickness failure presents an important structural vulnerability. This study aimed to develop an epoxy characterized by excellent interlaminar toughness that could be applied to filament-wound CFRP cylinders. The epoxy was modified with carbon nanotubes (CNTs) and halloysite nanotubes (HNTs), and the toughening effect of these nanomaterials on the CFRP composite was examined. The combination of CNTs and HNTs remarkably enhanced the interlaminar toughness of the epoxy and structurally improved the cohesiveness of individual nanoparticles, resulting in the partial reinforcement of the laminated structure of the CFRP. The reinforcements of the epoxy and interfacial bonding force between the epoxy and carbon fibers were also improved by the hybridization of small amounts of the CNTs and HNTs. In particular, the HNTs significantly improved the through-thickness characteristics of the CFRP by providing strong bridging effects. The interleaved CNT/HNT design developed in this work was suitable for application to hybrid-reinforced laminated CFRPs and may be considered a potential nanomaterial technology that could ensure the stable performance of CFRP-based structures against failure.

Tribute to E. J. Capaldi: Celebration of a Psychological Scientist

Abstract E. J. (John) Capaldi (1928–2020) made numerous contributions to experimental psychology in his long career at the University of Texas at Austin and Purdue University. He was a pioneer in the area of animal learning and cognition, known for his sequential theory of partial reinforcement extinction effects. His research in this area and in memory and counting phenomena was conducted for the most part with rats running in straight alley mazes under various sequences of trial outcomes (e.g., reward, nonreward, variations in reward size). John's other interests included the sequential theory applied to Pavlovian conditioning, evolutionary theory, and psychology of science. More generally, John was a scientist to the core who served as a role model to those who knew him. His career centered on the values of science and rigorous critical thinking based in empirical data, coupled with a curiosity and openness to different and new ideas in psychology.

Dissociating reward sensitivity and negative urgency effects on impulsivity in the five-choice serial reaction time task.

Negative urgency describes the tendency for rash and impulsive behaviour during negative emotional states and has been linked to a number of psychiatric disorders. However, there has been limited research on negative urgency as an explanatory mechanism for impulsivity in experimental animals. Such research has important implications for elucidating the neurobiology of negative urgency and thereby the development of future therapeutic interventions. In this study, we investigated the effects of negative urgency using a partial reinforcement schedule to increase the frequency of non-rewarded (i.e. frustrative) trials in the five-choice serial reaction time task, a widely used task to assess visual attention and impulsivity. Using a Markov chain model to analyse trial-by-trial outcomes we found that premature (i.e. impulsive) responses in the five-choice serial reaction time task were more likely to occur after a non-rewarded trial, and mostly after a previous premature trial. However, contrary to the frustration hypothesis of negative urgency, increasing the probability of reinforcement (p(R)) from p(R) = 0.5 to p(R) = 1 increased the number of premature responses in each session. Micro and macro levels of analyses revealed that impulsivity in the five-choice serial reaction time task is governed by at least two processes, one dependent on the overall level of reinforcement hypothesised to determine the state of behavioural activation, the second dependent on trial-by-trial outcomes consistent with negative urgency effects. These processes may depend on distinct neurobiological mechanisms and have relevance for neuropsychiatric disorders that implicate impulsive behaviours dependent on positive and negative affective states.

Frustrative nonreward and emotional self-medication:Factors modulating alcohol consumption following reward downshift in rats

Life experience involving unexpected incentive loss (e.g., loss of job or a significant other) may result in negative emotional reactions (frustration) and promote alcohol drinking. Similarly, animals exposed to a frustrative 32-to-4% sucrose downshift increase their preference for alcohol (2%) vs. water. This result was interpreted as reflecting emotional self-medication—the consumption of substances that reduce negative emotions. We conducted three experiments examining parametric manipulations of the animal model: (1) effects of a severe reward downshift (32-to-4% sucrose) on consumption of various alcohol concentrations (Experiment 1); (2) effects of different magnitudes of reward downshifts on consumption of 32% alcohol (Experiment 2); and (3) effects of partial reinforcement (an intervention that increases resistance to frustration) on 2% alcohol intake induced by a 32-to-4% sucrose downshift (Experiment 3). The results show that (1) a 32-to-4% sucrose downshift leads to an increase in alcohol intake over a wide range of alcohol concentrations; (2) the greater the reward downshift, the higher the relative increase in alcohol consumption; and (3) a treatment that increases resistance to frustration (partial reinforcement) also attenuates alcohol consumption after a sucrose downshift. These data are discussed in relation to the role of frustrative nonreward in alcohol consumption.

Implementation of Reinforcement Skill in Teaching English in The Pandemic Situation

This study aimed to identify the types of reinforcement skills and investigate the implementation of reinforcement skills used during the online learning process at SMP Laboratorium Undiksha Singaraja. This study used a qualitative descriptive method as the research design. This study also used an English teacher as the research subject. In collecting data, this study used three methods, namely; observation, interview, and questionnaires. This research was conducted online due to the COVID-19 pandemic. Through the data obtained, this study found the results of the type of reinforcement and the implementation used by teachers during online learning. There are four types of reinforcement used by the teachers, such as; (1) positive verbal reinforcement in the form of praise and partial reinforcement, (2) positive non-verbal reinforcement in the form of gestures, (3) negative verbal reinforcement in the form of enforceable statements, questions, calling out the students' names, and (4) negative non-verbal reinforcement in the form of facial expressions and record the students' misbehavior. In addition, the reinforcement implementation was relevant to the theories suggested by experts by following the five principles in giving reinforcement. Further study is needed to get a deeper understanding toward the implementation of reinforcement in EFL classroom.

Numerical Evaluation of the Upright Columns with Partial Reinforcement along with the Utilisation of Neural Networks with Combining Feature-Selection Method to Predict the Load and Displacement

This study evaluated the axial capacity of cold-formed racking upright sections strengthened with an innovative reinforcement method by finite element modelling and artificial intelligence techniques. At the first stage, several specimens with different lengths, thicknesses and reinforcement spacings were modelled in ABAQUS. The finite element method (FEM) was employed to increase the available datasets and evaluate the proposed reinforcement method in different geometrical types of sections. The most influential factors on the axial strength were investigated using a feature-selection (FS) method within a multi-layer perceptron (MLP) algorithm. The MLP algorithm was developed by particle swarm optimization (PSO) and FEM results as input. In terms of accuracy evaluation, some of the rolling criteria including results showed that geometrical parameters have almost the same contribution in compression capacity and displacement of the specimens. According to the performance evaluation indexes, the best model was detected and specified in the paper and optimised by tuning other parameters of the algorithm. As a result, the normalised ultimate load and displacement were predicted successfully.