Partial reinforcement and context switch effects in human predictive learning

Human participants were trained in a trial-by-trial contingency judgements task in which they had to predict the probability of an outcome (diarrhoea) following different cues (food names) in different contexts (restaurants). Cue P was paired with the outcome on half of the trials (partial reinforcement), while cue C was paired with the outcome on all the trials (continuous reinforcement), both cues in Context A. Test was conducted in both Context A and a different but equally familiar context (B). Context change decreased judgements to C, but not to P (Experiment 1). This effect was found only in the cue trained in the context where a different cue was partially reinforced (Experiment 2). Context switch effects disappeared when different cues received partial reinforcement in both contexts of training (Experiment 3). The implications of these results for an explanation of context switch effects in terms of ambiguity in the meaning of the cues prompting attention to the context (e.g., Bouton, 1997) are discussed.     

The legitimizing role of accent on discrimination against immigrants

This article analyses the influence of accent on discrimination against immigrants by examining the hypothesis that accent leads to discrimination only in more prejudiced individuals, merely because people speaking with a native accent are perceived to be better qualified than those whose accent is non‐standard. In Study 1 (N = 71), we found that only prejudiced individuals use accent to discriminate against immigrants. In Study 2 (N = 124), we replicated this effect and found that the influence of accent on discrimination is mediated by the perceived quality of the accent. Study 3 (N = 105) replicated the previous results even after controlling for the effect of stereotyping. These results are the first experimental illustration of the hypothesis that accent triggers intergroup discrimination only among prejudiced individuals because they evaluate native accents as being qualitatively better than accents of immigrants, thereby legitimizing ingroup bias.     

Context change and retention interval can have additive, rather than interactive, effects after taste aversion extinction

Spontaneous forgetting is often attributed to retrieval failure caused by natural changes in the background context that occur over time. However, some investigators have argued that the context-change account of forgetting is paradoxical, because context-change effects themselves decrease over time. To resolve the paradox, we have suggested that organisms may merely forget the physical context as the temporal context in which it is embedded changes; this explanation accepts a fundamental similarity between time and physical context. The present experiment tested an implication of this analysis by examining the interaction between retention interval and context change in rats after a taste aversion was conditioned and then extinguished. Importantly, subjects tested at the longer (24-day) retention interval received reminder exposure to the physical contexts before testing. Under these conditions, retention interval and context change both caused relapse of the extinguished aversion (spontaneous recovery and renewal, respectively), and the strongest overall relapse was observed when the two treatments were combined. Such additivity (rather than interactivity) is consistent with a context-change account of forgetting and sets the stage for resolution of the context-forgetting paradox.     

A new era for Estudios de Psicología / Una nueva era de Estudios de Psicología

Abstract

The journal Estudios de Psicología enters a new era, in which all issues will be dedicated to monographic themes. These themes may be proposed by either the journal Editor or authors themselves, who may submit a positioning article on a topic in the frontiers of psychology (as defined in a previous Editor’s comment, here translated into English and reproduced in its entirety) that will be sent to peer review. If the topic and the article are found to be of interest and relevance, its authors will become the Invited Editors of the monographic issue, and a call for papers will invite authors to send their articles on the chosen topic. The reasons behind this new method, as well as its implications, are presented and discussed.     

Outcome-specific transfer between predictive and instrumental learning is unaffected by extinction but reversed by counterconditioning in human participants

Three experiments were conducted to explore the effects of different interference treatments upon outcome-specific transfer from predictive learning to instrumental responding. A computer game was designed in which participants had to defend Andalusia from navy and air-force attacks. Participants learned the relationship between two instrumental responses (two keys in a standard keyboard) and two different outcomes (destruction of the ships or destruction of the planes). Then, they learned to predict which of two different cues predicted either outcome. Finally, participants were allowed to give either of the two instrumental responses in the presence of each cue. Outcome-specific transfer was shown as a preference for the response that shared the outcome with the current cue. Extinction of the cue before the transfer test had no effect upon transfer, regardless of the level of extinction (Experiments 1-3). However, pairing the cue with the alternative outcome (counterconditioning) reversed the outcome-based transfer effect (Experiment 3). The implications of these results for the contents of extinction in human predictive learning are discussed.     

The centrality of the female body in Brazilian culture: Evangelical and Muslim responses

This article aims to analyse how both Evangelical and Islamic religions deal with a central aspect of the construction of the Brazilian national identity: the body. The Brazilian religious field is exposed to this cultural value and reacts to it in different ways. While Islam preaches female modesty, involving the ‘concealment’ of the body and its forms, Evangelicals reinforce part of the Brazilian culture of appreciation and care for physical attributes, albeit using the rhetoric of doing so with moderation and modesty. The data presented here were collected through interviews with religious leaders and through participant observation in the Baptist Church of Lagoinha, in Belo Horizonte, and the Islamic Youth League, in São Paulo, Brazil.     

Transfer of control between causal predictive judgments and instrumental responding

Four experiments were conducted to explore outcome-specific transfer from causal predictive judgments to instrumental responding. A video game was designed in which participants had to defend Andalusia from navy and air force attacks. First, they learned the relationship between two instrumental responses (two key on a standard keyboard) and two different outcomes (destruction of the ships or destruction of the planes). Then they learned to predict which of two different stimuli predicted which outcome. Finally, they had the opportunity of making either of the two instrumental responses in the presence of either stimulus. Transfer was shown as a preference for the response that shared an outcome with the current stimulus. The presentation of the stimulus during the test produced a decrease in the overall rate of response. Responding to a neutral stimulus in Experiments 2 and 3 suggested that this overall decrease in responding was due to a combination of the time needed to process the meaning of the stimulus and the activation of the representation of the outcome in the presence of the stimulus during the test. Transfer between predictive judgments and instrumental responding mirrors the outcome-specific Pavlovian instrumental transfer observed in conditioning studies with rats.     

Context change as the mechanism of reinstatement in causal learning

Four experiments were conducted to explore the mechanism of reinstatement in human causal learning. After a retroactive interference treatment in which a stimulus was first followed by an outcome (A+) and then followed by a different outcome (A*), simple exposure to the original outcome (+) in the interference-test context produced partial reinstatement of the first-learned information (A+). When exposure to the outcome took place in a context different from the interference-test context, reinstatement was not observed (Experiment 1). Equivalent results appeared when the outcome presented during reinstatement was different from the one originally related to the stimulus affected by interference, independent of whether the interfering outcome (Experiments 2, 3, and 4) or a new outcome (Experiments 3 and 4) was presented before the test. These results suggest an interpretation of reinstatement in terms of a context change between interference and testing.     

Combined effect of context change and retention interval on interference in causality judgments

Four experiments studied the effects of context change and retention interval on retroactive interference in human causal learning. Experiment 1 found evidence of retroactive interference. Experiment 2 found that either a 48-hr retention interval or a change in the context after the interference treatment decreased retroactive interference. An interaction between context change and retention interval effects was also found, eclipsing the context change effect after the 48-hr retention interval. Experiments 3 and 4 found additivity between context change and retention interval effects when participants were remained of the difference between physical contexts before the test, independently of whether the context change involved a return to the original acquisition context. These results add to the evidence suggesting that spontaneous forgetting is caused by a change in either the physical or the temporal contexts where information is acquired.