Why is the Rescorla-Wagner model so influential?

The influence of the Rescorla-Wagner model cannot be overestimated, despite that (1) the model does not differ much computationally from its predecessors and competitors, and (2) its shortcomings are well-known in the learning community. Here we discuss the reasons behind its widespread influence in the cognitive and neural sciences, and argue that it is the constant search for general-process theories by learning scholars which eventually produced a model whose application spans many different areas of research to this day. We focus on the theoretical and empirical background of the model, the theoretical connections that it has with later developments across Marr's levels of analysis, as well as the broad variety of research that it has guided and inspired.

Subsampling of cues in associative learning.

Theories of learning distinguish between elemental and configural stimulus processing depending on whether stimuli are processed independently or as whole configurations. Evidence for elemental processing comes from findings of summation in animals where a compound of two dissimilar stimuli is deemed to be more predictive than each stimulus alone, whereas configural processing is supported by experiments using similar stimuli in which summation is not found. However, in humans the summation effect is robust and impervious to similarity manipulations. In three experiments in human predictive learning, we show that summation can be obliterated when partially reinforced cues are added to the summands in training and tests. This lack of summation only holds when the partially reinforced cues are similar to the reinforced cues (experiment 1) and seems to depend on participants sampling only the most salient cue in each trial (experiments 2a and 2b) in a sequential visual search process. Instead of attributing our and others' instances of lack of summation to the customary idea of configural processing, we offer a formal subsampling rule that might be applied to situations in which the stimuli are hard to parse from each other.

The Sometimes Context-Specific Habituation: Theoretical Challenges to Associative Accounts.

A substantial corpus of experimental research indicates that in many species, long-term habituation appears to depend on context-stimulus associations. Some authors have recently emphasized that this type of outcome supports Wagner's priming theory, which affirms that responding is diminished when the eliciting stimulus is predicted by the context where the animal encountered that stimulus in the past. Although we agree with both the empirical reality of the phenomenon as well as the principled adequacy of the theory, we think that the available evidence is more provocative than conclusive and that there are a few nontrivial empirical and theoretical issues that need to be worked out by researchers in the future. In this paper, we comment on these issues within the framework of a quantitative version of priming theory, the SOP model.

SOP- habituation laboratory: An interactive tool for simulating the basic behavioral features of habituation.

This paper presents an open-source online tool for introducing psychology students to the major theoretical and empirical facts of habituation. The tool was designed in a way that combines theory and data through simulated experiments. The simulations exemplify how the priming theory of Allan R. Wagner accounts for the set of behavioral characteristics of habituation proposed by Richard F. Thompson and W. Alden Spencer in 1966. Through this interactive platform, the user can learn the basics of the theory and examine how it accounts for the empirical facts with different parameters. Instructions and commands are provided in three languages: English, Spanish, and Portuguese.

Can the stimulus processing assumptions of the sometimes-opponent-process (SOP) model explain instances of contextual learning?

One of the most persisting assertions in Allan Wagner's view of conditioning is that the environment or context in which significant events occur can develop an association with these events, more or less in the same way as conditioned and unconditioned stimuli become associated with each other. He was drawn to this idea by evidence of contextual fear conditioning, contingency effects, some instances of context-specificity of long-term habituation, and latent inhibition. From a theoretical point of view, however, homologizing contexts to conditioned stimuli is not as simple as it seems, especially when quantitative theories are involved, as is the case of Wagner's work. It might be, for instance, that contexts cannot be represented merely as long-duration conditioned stimuli, in which case, no net contextual learning can occur due to the context being less correlated with reinforcement than with nonreinforcement. In this article, we use Wagner's sometimes-opponent-process model of conditioning to comment on the quantitative nature of this challenge. Also, based on an idea sketched by Mazur and Wagner, we describe a set of quantitative strategies that might be usefully considered to solve this dilemma within the general framework of Wagner's theory. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

A Quantitative Account of the Behavioral Characteristics of Habituation: The Sometimes Opponent Processes Model of Stimulus Processing.

Habituation is defined as a decline in responding to a repeated stimulus. After more than 80 years of research, there is an enduring consensus among researchers on the existence of 9-10 behavioral regularities or parameters of habituation. There is no similar agreement, however, on the best approach to explain these facts. In this paper, we demonstrate that the Sometimes Opponent Processes (SOP) model of stimulus processing accurately describes all of these regularities. This model was proposed by Allan Wagner as a quantitative elaboration of priming theory, which states that the processing of a stimulus, and therefore its capacity to provoke its response, depends inversely on the degree to which the stimulus is pre-represented in short-term memory. Using computer simulations, we show that all the facts involving within-session effects or short-term habituation might be the result of priming from recent presentations of the stimulus (self-generated priming). The characteristics involving between-sessions effects or long-term habituation would result from the retrieval of the representation of the stimulus from memory by the associated context (associatively generated priming).

The development and present status of the SOP model of associative learning.

The Sometimes Opponent Processes (SOP) model in its original form was especially calculated to address how expected unconditioned stimulus (US) and conditioned stimulus (CS) are rendered less effective than their novel counterparts in Pavlovian conditioning. Its several elaborations embracing the essential notion have extended the scope of the model to integrate a much greater number of phenomena of Pavlovian conditioning. Here, we trace the development of the model and add further thoughts about its extension and refinement.

A theoretical analysis of transfer of occasion setting: SOP with replaced elements.

The available data on occasion setting led Susan Brandon and Allan Wagner (Brandon and Wagner, 1998; Wagner and Brandon, 2001) to formulate what has come to be known as a replaced-elements conception (REM) of context-dependent cues within the SOP model (Wagner, 1981). In the present paper, we review the development of the theory, and show how, with a few congenial assumptions about shared cues, it can address some of the major regularities concerning when the transfer of occasion setting does or does not occur. Among the particular examples are the relatively unique transfers that have been reported to occur between separate serial discriminations and between targets that have been trained with the same versus different reinforcers.

A theoretical note in interpretation of the "redundancy effect" in associative learning.

In a recent series of papers, Pearce and colleagues (e.g., Pearce, Dopson, Haselgrove, & Esber, 2012) have demonstrated a so-called "redundancy effect" in Pavlovian conditioning, which is the finding of more conditioned responding to a redundant cue trained as part of a blocking procedure (A+AX+) than to a redundant cue trained as part of a simple discrimination procedure (BY+CY-). This phenomenon presents a serious challenge for those theories of conditioning that compute learning through a global error-term. In this paper, we use the Rescorla and Wagner (1972) model as a prototypical example to demonstrate that the redundancy effect can be accounted for by this class of theories if the experimental stimuli are assumed to share a common component. We also point to some domains in which this approach leads to novel predictions that may deserve empirical evaluation. (PsycINFO Database Record

The effect of cognitive load and outcome congruency on the learned predictiveness effect in human predictive learning / El efecto de la carga cognitiva y la congruencia de las consecuencias sobre el efecto de la predictibilidad aprendida en el aprendizaje predictivo humano

The learned predictiveness effect or LPE is the finding that when people learn that certain cues are reliable predictors of an outcome in an initial stage of training (phase 1), they exhibit a learning bias in favor of these cues in a subsequent training involving new outcomes (phase 2) despite all cues being equally reliable in phase 2. In Experiment 1, we replicate the basic effect and found that the addition of a secondary memory task during phase 2 had no reliable influence on the LPE. In Experiment 2, we demonstrated that the same secondary task can either facilitate or disrupt the LPE, depending on whether the outcomes of phase 1 were affectively congruent or incongruent with the outcomes of phase 2. These findings are discussed in relationship to associative and inferential accounts of LPE (AU)

El efecto de la predictibilidad aprendida o LPE, es el hallazgo de que cuando las personas aprenden que algunos estímulos son predictores fiables de una consecuencia en una primera etapa del entrenamiento (fase 1), muestran un sesgo de aprendizaje a favor de éstos estímulos en un entrenamiento posterior que implica nuevas consecuencias (fase 2), a pesar de que todos los estímulos son igualmente fiables en la fase 2. En el Experimento 1, replicamos el efecto básico y demostramos que la ejecución de una tarea de memoria secundaria durante la fase 2 no tuvo una influencia significativa sobre la LPE. En el Experimento 2, demostramos que la misma tarea secundaria puede facilitar o interrumpir la LPE, dependiendo de si las consecuencias de la fase 1 fueron congruentes o incongruentes afectivamente con las consecuencias de la fase 2. Estos hallazgos son discutidos en relación a las explicaciones asociativa e inferencial de la LPE (AU)

Why are some dimensions integral? Testing two hypotheses through causal learning experiments.

Compound generalization and dimensional generalization are traditionally studied independently by different groups of researchers, who have proposed separate theories to explain results from each area. A recent extension of Shepard's rational theory of dimensional generalization allows an explanation of data from both areas within a single framework. However, the conceptualization of dimensional integrality in this theory (the direction hypothesis) is different from that favored by Shepard in his original theory (the correlation hypothesis). Here, we report two experiments that test differential predictions of these two notions of integrality. Each experiment takes a design from compound generalization and translates it into a design for dimensional generalization by replacing discrete stimulus components with dimensional values. Experiment 1 showed that an effect analogous to summation is found in dimensional generalization with separable dimensions, but the opposite effect is found with integral dimensions. Experiment 2 showed that the analogue of a biconditional discrimination is solved faster when stimuli vary in integral dimensions than when stimuli vary in separable dimensions. These results, which are analogous to more "non-linear" processing with integral than with separable dimensions, were predicted by the direction hypothesis, but not by the correlation hypothesis. This confirms the assumptions of the unified rational theory of stimulus generalization and reveals interesting links between compound and dimensional generalization phenomena.

Cue competition effects in human causal learning.

Five experiments involving human causal learning were conducted to compare the cue competition effects known as blocking and unovershadowing, in proactive and retroactive instantiations. Experiment 1 demonstrated reliable proactive blocking and unovershadowing but only retroactive unovershadowing. Experiment 2 replicated the same pattern and showed that the retroactive unovershadowing that was observed was interfered with by a secondary memory task that had no demonstrable effect on either proactive unovershadowing or blocking. Experiments 3a, 3b, and 3c demonstrated that retroactive unovershadowing was accompanied by an inflated memory effect not accompanying proactive unovershadowing. The differential pattern of proactive versus retroactive cue competition effects is discussed in relationship to amenable associative and inferential processing possibilities.

Especificidad contextual diferencial en la habituación de las respuestas de parpadeo y aceleración cardiaca en humanos / Differential Context-Specificity in the Habituation of the Eyeblink and Cardiac Responses in Humans

Wagner (1978) propuso que la habituación, definida como una disminución en la respuesta a un estímulo que se repite, dependería de la formación de una asociación entre el contexto y el estímulo. Según este enfoque, la habituación debería ser contexto-específica, es decir, la respuesta habituada en un contexto debería deshabituarse al presentar el estímulo en un contexto novedoso. Esta hipótesis fue examinada a través de un experimento donde se sometió a un grupo de estudiantes a una sesión de habituación consistente en 60 repeticiones de un estímulo provocador de reacciones de parpadeo y aceleración cardiaca. Posteriormente, en una sesión de prueba se midió la amplitud de estas respuestas, presentando el estímulo en el mismo contexto (Grupo Igual) o en un contexto distinto a aquel donde ocurrió la habituación (Grupo Diferente). Los resultados de la prueba arrojaron evidencia de especificidad contextual diferencial para ambas respuestas, ya que la respuesta de aceleración cardiaca resultó disminuida en el grupo igual pero no en el grupo diferente (revelando especificidad), mientras que la respuesta de parpadeo estuvo igualmente disminuida en ambos grupos (revelando ausencia de especificidad). Estos hallazgos confirman observaciones previas con ratas que demuestran que el control contextual de la habituación depende de la naturaleza de la respuesta.

Wagner (1978) proposed that habituation, defined as a decrease in responding to a repeated stimulus, would depend on the formation of an association between the stimulus and the context. According to this approach, habitua-tion should be context-specific; that is, a response that was habituated in a given context should dishabituate when the stimulus is presented in a novel context. This hypothesis was examined in an experiment in which a group of students received a habituation session consisting of 60 repetitions of a stimulus capable of evoking eyeblink and heart-rate acceleration reactions. Subsequently, in a testing session the amplitude of these responses was examined by presenting the stimulus in the same context used in the habituation session (Group Same) or in an alternative context (Group Different). The results provided evidence of differential context-specificity for the two responses, since the heart-rate acceleration response was diminished in the group same but not in the group different (revealing specificity), while the eyeblink response was diminished in both groups (revealing no specificity). These findings are consistent with previous observations in rats demonstrating that the contextual control of habituation depends on the nature of the measured response.

Reinstatement of short-latency responses after asymptotic Pavlovian conditioning training by the presentation of an extraneous stimulus.

The purpose of this study was to examine whether the progressive disappearance of short-latency conditioned responses, or inhibition of delay, observed in Pavlovian conditioning with long inter-stimulus intervals, could be reverted by the presentation of a novel stimulus. In one experiment, two groups of rabbits received extensive training with a short (250 ms) or a long (1500 ms) tone that overlapped and terminated with a periorbital shock unconditioned stimulus. After training, the presentation of an extraneous stimulus prior to tone onset produced a reinstatement of short latency CRs in the group trained with the long CS, but did not affect CR latency in the group trained with the short CS. This finding is consistent with Pavlov's (1927) view that conditioning with long conditioned stimuli involves the acquisition of response tendencies in the early portion of the stimulus that are subsequently suppressed by the development of an inhibitory process.

Reinstatement of short-latency responses after asymptotic Pavlovian conditioning training by the presentation of an extraneous stimulus

The purpose of this study was to examine whether the progressive disappearance of short-latency conditioned responses, or inhibition of delay, observed in Pavlovian conditioning with long inter-stimulus intervals, could be reverted by the presentation of a novel stimulus. In one experiment, two groups of rabbits received extensive training with a short (250 ms) or a long (1500 ms) tone that overlapped and terminated with a periorbital shock unconditioned stimulus. After training, the presentation of an extraneous stimulus prior to tone onset produced a reinstatement of short latency CRs in the group trained with the long CS, but did not affect CR latency in the group trained with the short CS. This finding is consistent with Pavlov's (1927) view that conditioning with long conditioned stimuli involves the acquisition of response tendencies in the early portion of the stimulus that are subsequently suppressed by the development of an inhibitory process.

Habituation of the eyeblink response in humans with stimuli presented in a sequence of incremental intensity.

In an experiment we examined whether the repeated presentation of tones of gradually increasing intensities produces greater decrement in the eyeblink reflex response in humans than the repetition of tones of constant intensities. Two groups of participants matched for their initial level of response were exposed to 110 tones of 100-ms duration. For the participants in the incremental group, the tones increased from 60- to 90- dB in 3-dB steps, whereas participants in the constant group received the tones at a fixed 90-dB intensity. The results indicated that the level of response in the last block of 10 trials, in which both groups received 90-dB tones, was significantly lower in the incremental group than in the constant group. These findings support the data presented by Davis and Wagner (7) with the acoustic response in rats, but differ from several reports with autonomic responses in humans, where the advantage of the incremental condition has not been observed unambiguously. The discussion analyzes theoretical approaches to this phenomenon and the possible involvement of separate neural circuits.

Habituation of the eyeblink response in humans with stimuli presented in a sequence of incremental intensity

In an experiment we examined whether the repeated presentation of tones of gradually increasing intensities produces greater decrement in the eyeblink reflex response in humans than the repetition of tones of constant intensities. Two groups of participants matched for their initial level of response were exposed to 110 tones of 100-ms duration. For the participants in the incremental group, the tones increased from 60- to 90- dB in 3-dB steps, whereas participants in the constant group received the tones at a fixed 90-dB intensity. The results indicated that the level of response in the last block of 10 trials, in which both groups received 90-dB tones, was significantly lower in the incremental group than in the constant group. These findings support the data presented by Davis and Wagner (7) with the acoustic response in rats, but differ from several reports with autonomic responses in humans, where the advantage of the incremental condition has not been observed unambiguously. The discussion analyzes theoretical approaches to this phenomenon and the possible involvement of separate neural circuits.

Psychology and natural disasters: earthquake and tsunami in Chile on February 27, 2010 / Psicología y desastres naturales: terremoto y tsunami: del 27 de febrero de 2010 en Chile

Esta edición especial de Terapia Psicológica surge como un intento por sistematizar la información preliminar recolectada por investigadores acerca de las consecuencias psicológicas del desastre natural ocurrido en la zona centro sur de Chile el 27 de Febrero de 2010. Esta edición también se focaliza en las formas de intervención psicológica que se han aplicado en la distintas zonas devastadas, enfatizándose, además, la necesidad de concebir intervenciones para los efectos de mediano y largo plazo de este fenómeno. Por último, se revisan estrategias utilizadas en otros países para abordar desastres naturales.

This special issue of Terapia Psicológica is an attempt to organize preliminary information collected by researchers on the psychological consequences of the natural disaster occurred in the south central zone of Chile on February 27, 2010. This issue is also focused on the types of psychological interventions that have been conducted in the affected zones, also emphasizing the need to define intervention strategies for middle- and long-term effects of this phenomenon. Finally, some intervention strategies applied in other countries are reviewed.

Asociaciones excitatorias entre el contexto y la consecuencia en la reinstalación de respuestas extinguidas en el aprendizaje causal humano / Excitatory context-consequence associations in the reinstatement of extinguished responses in human causal learning

En dos experimentos, estudiantes universitarios aprendieron una relación predictiva entre un evento y una consecuencia, la que posteriormente fue extinguida presentando el evento sin la consecuencia. En el Experimento 1, se presentó la consecuencia por sí sola después de la extinción, ocasionando la reaparición de la relación predictiva aprendida originalmente, asemejándose al fenómeno del condicionamiento Pavloviano conocido como "reinstalación". Este experimento demostró además, que no es necesario apelar a asociaciones inhibitorias para explicar la reinstalación, sino que solamente a asociaciones excitatorias entre el contexto y la consecuencia. El Experimento 2 confirmó la generalidad de estos hallazgos utilizando otro procedimiento de aprendizaje causal. Se discuten estos hallazgos en términos de las diferencias entre el aprendizaje causal y el condicionamiento Pavloviano y de la posible existencia de dos mecanismos alternativos de extinción: desaprendizaje para extinguir asociaciones no consolidadas e inhibición para las consolidadas.

In two experiments, undergraduates learned a predictive relationship between an event and a consequence, which was subsequently extinguished by presenting the event without the consequence. In Experiment 1, participants were exposed to the consequence by itself after extinction, occasioning the reappearance of the originally learned predictive relationship, resembling a phenomenon known as Reinstatement in the field of Pavlovian conditioning. This experiment further demonstrated that reinstatement can be explained without appealing to inhibitory associations, but only by mean of excitatory associations between the context and the consequence. Experiment 2 confirmed the generality of these findings using a different procedure of causal learning. The findings are discussed in terms of differences between Pavlovian conditioning and causal learning and of the possible existence of two mechanisms of extinction: unlearning to extinguish non consolidated associations and inhibition for the consolidated associations.

Summation in predictive learning in children

Una cantidad considerable de investigación ha examinado las predicciones contrarias de los modelos elementalistas y configuracionales del aprendizaje. Uno de los métodos más simples para distinguir entre estos dos enfoques es la prueba de sumación, en la cual se examina la fuerza asociativa de un estímulo compuesto novedoso (AB) después del entrenamiento por separado de cada uno de sus elementos (A+ y B+). El enfoque configuracional predice que la fuerza asociativa del compuesto será aproximadamente el promedio de la fuerza asociativa de sus componentes, mientras que el enfoque elementalista predice que la fuerza del compuesto será mayor que la de cada uno de los elementos por separado. La prueba de sumación ha arrojado evidencia contradictoria en experimentos con animales así como también con humanos adultos. El propósito de la presente investigación fue examinar el fenómeno de sumatoria en el aprendizaje predictivo en niños de 5-9 años de edad. Los resultados arrojaron evidencia de sumatoria (AB mayor que A y B) luego un procedimiento de entrenamiento con “sumatoria simple” (A+ B+ y test con AB; Experimento 1, n=26), pero no evidencia de sumatoria luego de un procedimiento de “preservación de la inhibición condicionada” (A+B-ABseguido por B+ y test con AB; Experimento 2; n=26). En el Experimento 3 ambos efectos se observaron simultáneamente (n=14). Estos resultados son consistentes con hallazgos en condicionamiento clásico con animales y aprendizaje predictivo con adultos. Se discuten algunas alternativas teóricas dentro de los enfoques elementalista y configuracional(AU)

Considerable research has examined the contrasting predictions of configural and elemental associative accounts of learning. One of the simplest methods to distinguish between these approaches is the summation test, in which the associative strength of a novel compound (AB) made of two separately-trained cues (A+ and B+) is examined. The configural view predicts that the strength of the compound will approximate the average strength of its components, whereas the elemental approach predicts that the strength of the compound will be greater than the strength of either component. The summation test has lead to contradictory evidence in experiments with animals as well as with human adults. The purpose of this research was to examine summation in predictive learning of 5- 9 years old children. The results provided evidence of summation (i.e., AB greater than A and B) after training with a “simple summation” procedure (A+ B+ test with AB; Experiment 1, n=26); but no summation following a “preserved conditioned inhibition” procedure (i.e., A+ B- AB- followed by B+; and test with AB; Experiment 2, n=26). In Experiment 3, both effects were simultaneously observed (n=14). These results are consistent with reported findings in both Pavlovian conditioning with animals and predictive learning with adult humans. Theoretical alternatives within the elemental and configural approaches are discussed(AU)