The impact of emotional valence on generalization gradients.

Generalization enables individuals to respond to novel stimuli based on previous experiences. The degree to which organisms respond is determined by their physical resemblance to the original conditioned stimulus (CS+), with a stronger response elicited by more similar stimuli, resulting in similarity-based generalization gradients. Recent research showed that cognitive or conceptual dimensions also result in gradients similar to those observed with manipulations of physical dimensions. Such findings suggest that attributes beyond physical similarity play a role in shaping generalization gradients. However, despite its adaptive relevance for survival, there is no study exploring the effectiveness of affective dimensions in shaping generalization gradients. In two experiments (135 Spanish and 150 English participants, respectively), we used an online predictive learning task, in which different stimuli (words and Gabor patches) were paired with the presence - or absence - of a fictitious shock. After training, we assessed whether valence (i.e., hedonic experience) conveyed by words shape generalization gradients. In Experiment 1, the outcome expectancy decreased monotonically with variations in valence of Spanish words, mirroring the gradient obtained with the physical dimension (line orientation). In Experiment 2, conducted with English words, a similar gradient was observed when non-trained (i.e., generalization) words varied along the valence dimension, but not when words were of neutral valence. The consistency of these findings across two different languages strengthens the reliability and validity of the affective dimension as a determinant of generalization gradients. Furthermore, our data highlight the importance of considering the role of affective features in generalization responses, advancing the interplay between emotion, language, and learning.

Further evidence for the role of temporal contiguity as a determinant of overshadowing.

Three experiments explored whether weakening temporal contiguity between auditory cues and an aversive outcome attenuated cue competition in an avoidance learning task with human participants. Overall, with strong temporal contiguity between auditory cues and the outcome during training (the offset of the predictive auditory signals concurred with the onset of the outcome), the target cue trained as part of a compound yielded less avoidance behaviour than the control cue trained alone, an instance of overshadowing. However, weakening temporal contiguity during training (inserting a 5-s trace) attenuated overshadowing, resulting in similar avoidance behaviour in response to the control and target cues. These results provide evidence that, as predicted by a recent modification of Pearce's configural theory, temporal contiguity is critical for determining cue competition.

Category relevance attenuates overshadowing in human predictive learning.

In situations in which multiple predictors anticipate the presence or absence of an outcome, cues compete to anticipate the outcome, resulting in a loss of associative strength compared to control conditions without additional cues. Critically, there are multiple factors modulating the magnitude and direction of such competition, although in some scenarios the effect of these factors remains unexplored. We sought to assess whether the relative salience of the elements in a compound of cues modulates the magnitude of the overshadowing effect in human predictive learning. Two separable categories (i.e., colors and symbols) were used in a predictive learning task. In Experiment 1, different groups of participants were granted with different time of exposure to a compound of cues belonging to different categories (color and symbol) to evaluate potential differences in the magnitude of overshadowing. Furthermore, we used posttest questionnaires to assess whether participants used either only one or both categories during training, and assessed if this impacted the magnitude of overshadowing. In general, overshadowing was not modulated by the time of exposition, except in the case of very short time of exposition with prominent learning about the most salient category. In Experiment 2, the relative salience of a category was biased via prior experience either with a biconditional discrimination or attending only the relevant category (either color or symbol). The previously relevant category was less prone to overshadowing, but not the alternative one. Results are discussed in light of attentional and configural theories of associative learning. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Conditioned place avoidance in the planaria Schmidtea mediterranea: A pre-clinical invertebrate model of anxiety-related disorders.

The objective of the present study was to develop a model of avoidance learning and its extinction in planarians (Schmidtea mediterranea). Based on previous experiments showing conditioned place preference, we developed a procedure to investigate conditioned place avoidance (CPA) using shock as an unconditioned stimulus (US) and an automated tracking system to record the animals' behaviour. In Experiment 1, we assessed the unconditioned properties of different shock intensities by measuring post shock activity. In two subsequent experiments we investigated CPA using different designs, surfaces as conditioned stimuli (CSs; rough and smooth), and different US intensities (5 V and 10 V). In general, we observed the successful development of CPA. However, CPA was stronger with higher shock intensities, and we found that, in our preparation, a rough surface is best at entering into an association with the shock than a smooth surface. Finally, we also observed extinction of CPA. The evidence of CPA and its extinction in flatworms validates the planaria as a pre-clinical model for the study of avoidance learning, a hallmark of anxiety disorders.

Contiguity and overshadowing interactions in the rapid-streaming procedure.

When multiple cues are associated with the same outcome, organisms tend to select between the cues, with one revealing greater behavioral control at the expense of the others (i.e., cue competition). However, non-human and human studies have not always observed this competition, creating a puzzling scenario in which the interaction between cues can result in competition, no interaction, or facilitation as a function of several learning parameters. In five experiments, we assessed whether temporal contiguity and overshadowing effects are reliably observed in the streamed-trial procedure, and whether there was an interaction between them. We anticipated that weakening temporal contiguity (ranging from 500 to 1,000 ms) should attenuate competition. Using within-subject designs, participants experienced independent series of rapid streams in which they had to learn the relationship between visual cues (presented either alone or with another cue) and an outcome, with the cue-outcome pairings being presented with either a delay or trace relationship. Across experiments, we observed overshadowing (Experiments 1, 2, 4, and 5) and temporal contiguity effects (Experiments 2, 3, and 4). Despite the frequent occurrence of both effects, we did not find that trace conditioning abolished competition between cues. Overall, these results suggest that the extent to which contiguity determines cue interactions depends on multiple variables, some of which we address in the General discussion.

Social and non-social categorisation in investment decisions and learning.

Categorical processes allow us to make sense of the environment effortlessly by grouping stimuli sharing relevant features. Although these processes occur in both social and non-social contexts, motivational, affective, and epistemic factors specific to the social world may motivate individuation over categorisation of social compared with non-social stimuli. In one experiment, we tested this hypothesis by analysing the reliance on categorical versus individuating information when making investment decisions about social and non-social targets. In an adaptation of the iterative trust game, participants from three experimental groups had to predict the economic outcomes associated with either humans (i.e., social stimuli), artificial races (i.e., social-like stimuli), or artworks (i.e., non-social stimuli) to earn economic rewards. We observed that investment decisions with humans were initially biased by categorical information in the form of gender stereotypes, but later improved through an individuating learning approach. In contrast, decisions made with non-social stimuli were initially unbiased by categorical information, but the category-outcomes associations learned through repeated interactions were quickly used to categorise new targets. These results are discussed along with motivational and perceptual mechanisms involved in investment decisions and learning about social and non-social agents.

Social overshadowing: Revisiting cue-competition in social interactions.

In a large variety of contexts, it is essential to use the available information to extract patterns and behave accordingly. When it comes to social interactions for instance, the information gathered about interaction partners across multiple encounters (e.g., trustworthiness) is crucial in guiding one's own behavior (e.g., approach the trustworthy and avoid the untrustworthy), a process akin to trial-by-trial learning. Building on associative learning and social cognition literatures, the present research adopts a domain-general approach to learning and explores whether the principles underlying associative learning also govern learning in social contexts. In particular, we examined whether overshadowing, a well-established cue-competition phenomenon, impacts learning of the cooperative behaviors of unfamiliar interaction partners. Across three experiments using an adaptation of the iterated Trust Game, we consistently observed a 'social overshadowing' effect, that is, a better learning about the cooperative tendencies of partners presented alone compared to those presented in a pair. This robust effect was not modulated by gender stereotypes or beliefs about the internal communication dynamics within a pair of partners. Drawing on these results, we argue that examining domain-general learning processes in social contexts is a useful approach to understanding human social cognition.

Temporal contiguity determines overshadowing and potentiation of human Action-Outcome performance.

Three experiments (n = 81, n = 81, n = 82, respectively) explored how temporal contiguity influences Action-Outcome learning, assessing whether an intervening signal competed, facilitated, or had no effect on performance and causal attribution in undergraduate participants. Across experiments, we observed competition and facilitation as a function of the temporal contiguity between Action and Outcome. When there was a strong temporal relationship between Action and Outcome, the signal competed with the action, hindering instrumental performance but not causal attribution (Experiments 1 and 3). However, with weak temporal contiguity, the same signal facilitated both instrumental performance and causal attribution (Experiments 1 and 2). Finally, the physical intensity of the signal determined the magnitude of competition. As anticipated by associative learning models, a more salient signal attenuated to a greater extent instrumental performance (Experiment 3). These results are discussed by reference to a recent adaptation of the configural theory of learning.

Temporal and spatial contiguity are necessary for competition between events.

Over the last 50 years, cue competition phenomena have shaped theoretical developments in animal and human learning. However, recent failures to observe competition effects in standard conditioning procedures, as well as the lengthy and ongoing debate surrounding cue competition in the spatial learning literature, have cast doubts on the generality of these phenomena. In the present study, we manipulated temporal contiguity between simultaneously trained predictors and outcomes (Experiments 1-4), and spatial contiguity between landmarks and goals in spatial learning (Supplemental Experiments 1 and 2; Experiment 5). Across different parametric variations, we observed overshadowing when temporal and spatial contiguity were strong, but no overshadowing when contiguity was weak. Thus, across temporal and spatial domains, we observed that contiguity is necessary for competition to occur, and that competition between cues presented simultaneously during learning is absent when these cues were either spatially or temporally discontiguous from the outcome. Consequently, we advance a model in which the contiguity between events is accounted for and which explains these results and reconciles the previously contradictory findings observed in spatial learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Relapse after incentivized choice treatment in humans: A laboratory model for studying behavior change.

Behavior change interventions that incentivize desired behavior are highly effective for improving personal health, but difficult to maintain long term. Relapse is common and examining the mechanisms that contribute to relapse in experimental settings can identify processes relevant to substance abuse treatment. We developed a laboratory task that parallels a recent operant model of relapse after incentivized choice reported in the rodent laboratory. In two experiments, undergraduate participants first learned to make an operant response (keyboard button; R1) to earn a reinforcer consisting of an image of a preferred snack food (O1). In a second phase (Phase 2), R1 was still reinforced, but a new response (R2) was introduced and reinforced with a different reinforcer (a coin; O2). In a test phase, contingent incentives for R2 were removed (extinction) and relapse of R1 was assessed. Experiment 1 found that the O2 contingency suppressed R1 during Phase 2, and R1 relapsed rapidly in the test. Neither effect was consistently related to O2 value. Experiment 2 examined whether noncontingent presentations of O1 or O2 during the test could weaken relapse. Here, we found that noncontingent reinforcers did little to reduce or slow the increase in R1 responding. The present experiments highlight a laboratory approach to studying variables that may influence relapse after incentivized treatment. We identify and discuss areas for development to address differences between the present results and prior observations from animal and clinical studies. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Reversing the relationship between a nontarget cue and the outcome facilitates subsequent human predictive learning.

Two experiments were conducted to test the effect of experiencing associative interference on later learning. A predictive learning task was used in which human participants had to evaluate whether plants would grow or not (Outcome) after being watered with different fertilizers (Cues). Experiment 1 found that the increase in the prediction error produced by following a pre-exposed nontarget cue by the outcome, facilitated subsequent acquisition of the relationship between the pre-exposed target cue and the outcome. Experiment 2 compared whether learning about the target cue was differentially affected by experiencing two types of associative interference with the nontarget cue: Pairing the pre-exposed cue with the outcome and presenting the cue without outcome after being paired with it. The experience of associative interference with nontarget cues similarly facilitated subsequent learning about the target cue, regardless of the direction of the change in the nontarget cue-outcome relationship. It is suggested that the increase in prediction error produced by the experience of associative interference may lead to a general increase in attention that facilitates subsequent learning.

Reversal training facilitates acquisition of new learning in a Morris water maze.

Two experiments determined the effect of interference training on subsequent spatial learning in a Morris water maze. Rats first learned that a platform was located in a quadrant marked by landmarks A and B. Different groups of rats either continued or reversed that training. In the reversal condition the platform was opposite to the initially trained quadrant. On test, a new cue, C, was added and the platform was located in the new AC quadrant. Rats that had received the reversal training learned the location of the new platform faster than rats trained with the same platform throughout. In Experiment 2, phase 1 training was conducted by placing the rats on the platforms to ensure that they were located. Experimental rats received a reversal of the platform position in phase 2. A control group received training with both platforms present, and thus had experience with each. When the platform was then located in the new AC quadrant the rats that received reversal training learned the new location faster than those without reversal training. Results are discussed in terms of the effect of interference on the arousal of general attention.

Prior extinction increases acquisition context specificity in human predictive learning.

One experiment evaluated the effect of extinction on the context dependence of non-extinguished information in a situation in which physical (images), rather than predominantly verbal, contexts were used in human predictive learning. Participants received training in which different foods (Cues) were associated with the presence or the absence of gastric illness (outcome) in customers of different restaurants (contexts). One cue was associated with the gastric illness while a different cue was either extinguished or not between groups. A change in the context at test led to a general decrease in both predictive judgments and the speed of responding to the non-extinguished cue. However, these decreases were greater when training was conducted during extinction of the different cue demonstrating the extinction makes acquisition context-specific (EMACS) effect. Results are contrasted with failures to find the effect in other reports and discussed in terms of extinction leading to an allocation of attentional resources to the context, facilitating the context dependence of information.

Discrimination reversal facilitates subsequent acquisition of temporal discriminations in rats' appetitive conditioning.

Three experiments with rats assessed the effects of introducing predictive ambiguity by reversing a Pavlovianly trained discrimination on subsequent context and temporal conditioning. The experience of discrimination reversal did not facilitate context conditioning when the food was presented on a variable time schedule (Experiment 1a). However, in Experiment 1b, discrimination reversal enhanced subsequent learning of a fixed temporal interval associated with unsignaled food presentation in comparison with consistent training. In Experiment 2, temporal discrimination after reversal and consistent training was compared with a naïve control. The experience of discrimination facilitated subsequent temporal conditioning with respect to the naïve control, and discrimination reversal enhanced temporal conditioning even further. In Experiment 3, reversal enhanced learning of the fixed temporal interval, regardless of whether it was relatively short or long (i.e., 30 s or 60 s). Results are discussed in terms of current associative theories of human and nonhuman conditioning and attention. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Experiencing extinction with a non-target cue facilitates reversal of a target conditioned inhibitor in human predictive learning.

Three experiments tested the effect of experiencing extinction on learning about a differential conditioned inhibitor that was trained as an excitor. A human predictive learning task was used in which participants had to evaluate the probability of different colored fertilizers (Cues) leading plants to flourish or not (Outcome). Experiment 1 found that presenting the target cue without outcome while other cues were followed by the outcome made the target cue a conditioned inhibitor, passing both, retardation (Experiment 1a) and summation (Experiment 1b) tests of conditioned inhibition. Subsequent extinction of a different cue facilitated reversing the relationship between the conditioned inhibitor and the outcome regardless of whether the situation could be solved by using simple rules (Experiment 2) or not (Experiment 3). Results are discussed in terms of attentional theories that suggest extinction produces a nonspecific increase in attention that facilitates learning.

Stimulus control of actions and habits: A role for reinforcer predictability and attention in the development of habitual behavior.

Goal-directed actions are instrumental behaviors whose performance depends on the organism's knowledge of the reinforcing outcome's value. In contrast, habits are instrumental behaviors that are insensitive to the outcome's current value. Although habits in everyday life are typically controlled by stimuli that occasion them, most research has studied habits using free-operant procedures in which no discrete stimuli are present to occasion the response. We therefore studied habit learning when rats were reinforced for lever pressing on a random-interval 30-s schedule in the presence of a discriminative stimulus (S) but not in its absence. In Experiment 1, devaluing the reinforcer with taste aversion conditioning weakened instrumental responding in a 30-s S after 4, 22, and 66 sessions of instrumental training. Even extensive practice thus produced goal-directed action, not habit. Experiments 2 and 3 contrastingly found habit when the duration of S was increased from 30 s to 8 min. Experiment 4 then found habit with the 30-s S when it always contained a reinforcer; goal-directed action was maintained when reinforcers were earned at the same rate but occurred in only 50% of Ss (as in the previous experiments). The results challenge the view that habits are an inevitable consequence of repeated reinforcement (as in the law of effect) and instead suggest that discriminated habits develop when the reinforcer becomes predictable. Under those conditions, organisms may pay less attention to their behavior, much as they pay less attention to signals associated with predicted reinforcers in Pavlovian conditioning. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Discrimination reversal facilitates contextual conditioning in rats' appetitive conditioning / La inversión de la discriminación facilita el condicionamiento contextual en una preparación de condicionamiento apetitivo con ratas

Two experiments were conducted with the goal of exploring the effect of experiencing associative interference upon concurrent learning about conditioned stimuli and contexts in rats’ appetitive conditioning. During the first training phase, two groups of rats received a conditioned stimulus (CS1) followed by food, whereas another conditioned stimulus (CS2) was presented alone. During a second training phase, discrimination was reversed in group R, while it remained the same in group D. A new conditioned stimulus (CS3) was concurrently trained followed by food during this second Phase (Experiment 1). Reversal discrimination did not facilitate concurrent conditioning of the new stimulus, but there was a trend towards facilitation of contextual conditioning, measured by magazine entries in the absence of stimuli, that was confirmed in Experiment 2. These results suggest that the interference treatment may facilitate context conditioning under circumstances and with boundaries that are yet to be established

Se realizaron dos experimentos con el objetivo de explorar el efecto de experimentar una interferencia asociativa sobre el aprendizaje concurrente acerca de estímulos condicionados y contextos en condicionamiento apetitivo con ratas. Durante la primera fase de entrenamiento, dos grupos de ratas recibieron un estímulo condicionado (CS1) seguido de comida, mientras otro (CS2) se presentaba solo. Durante la segunda fase de entrenamiento, la discriminación se invirtió en el grupo R, mientras se mantuvo constante en el grupo D. Durante esta segunda fase, un estímulo condicionado nuevo (CS3) fue presentado seguido de comida (Experimento 1). La inversión de la discriminación no facilitó el aprendizaje concurrente acerca del nuevo estímulo, pero sí hubo una tendencia hacia la facilitación del condicionamiento contextual, medido a partir de la respuesta de entrada en el comedero en ausencia de estimulación, que se confirmó en el Experimento 2. Estos resultados sugieren que los tratamientos de interferencia pueden facilitar el condicionamiento contextual en circunstancias y con limitaciones que están aún por determinarse

Attentional perspectives on context-dependence of information retrieval

Attention has been traditionally understood as an important factor on acquiring new information. A review of the literature suggests that attention, specifically attention to the contexts, also plays a relevant role on information retrieval. It also shows that attention to the contexts is modulated by the ambiguity of the situation, and the informative value contexts have. The virtues and limitations of different attentional theories of learning applied to the explanation of the effects of context change on retrieval of the information are discussed. This analysis uncovers the weaknesses of current research on context processing that should be corrected by future research: The need of independent measures of attention to the contexts, the evaluation of the mechanisms of contextual control, and the possibility of taking an evolutionary perspective on the effects of context change (AU)

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