Backward blocking: the role of within-compound associations and interference between cues trained apart

Most theoretical accounts of backward blocking place heavy stress on the necessity of the target cue having been trained in compound with the competing cue to produce a decrement in responding. Yet, other evidence suggests that a similar reduction in responding to the target cue can be observed when the outcome is later paired with a novel cue never trained in compound with the target cue (interference between cues trained apart). The present experiment shows that pairing another nonassociated cue with the same outcome may be sufficient to produce a decremental effect on the target cue, but the presence of a within-compound association between the target and the competing cue adds to this effect. Thus, both interference between cues trained apart and within-compound associations independently contribute to backward blocking.     

The Future Similarity Objection Revisited

David Lewis has long defended an analysis of counterfactuals in terms of comparative similarity of possible worlds. The purpose of this paper is to reevaluate Lewis’s response to one of the oldest and most familiar objections to this proposal, the future similarity objection.     

Social and Economic Exchange: Construct Development and Validation

This study examined the economic and social exchanges between employee and employer within a model in which perceived organizational support and affective and continuance commitment served as predictors and performance, altruism citizenship behavior, absence, and lateness served as outcomes. Two samples were used. 384 master of business administration students participated in Study 1, and Study 2 consisted of 181 aerospace employees and their managers, working for a single organization. Both studies supported the distinctiveness between economic and social exchanges. Study 2 showed the overall fit of the proposed model was adequate, though only social exchange, and not economic exchange, directly predicted the performance outcomes. These results suggest the importance of perceived exchanges between employee and employer.     

Psychometric properties of the Spanish version of the Revised Competitive State Anxiety Inventory-2 with athletes

The aim of this work was to develop a Spanish adaptation of the Revised Competitive State Anxiety Inventory-2. The scale was translated and its psychometric properties were analyzed with data from a sample of 149 athletes. Exploratory and confirmatory factor analyses were performed which supported a 16-item CSAI-2R assessing the three hypothesised dimensions of anxiety: Somatic anxiety, Cognitive anxiety, and Self-confidence. Overall fit of the model was good with a value of .97 for Comparative and Non-Normed Fit Indexes, and .045 for Root Mean Square Error of Approximation. Cronbach alpha coefficients for the factors ranged from .79 to .83. It is concluded that this version shows adequate properties, in terms of its dimensionality and internal consistency. Guidelines are also provided for future research on its validity as a measure of state anxiety in competitive situations.     

Prior experience affects amodal completion in pigeons

In a three-alternative forced-choice task, 4 pigeons were trained to discriminate a target stimulus consisting of two colored shapes, one of which partially occluded the other, from two foil stimuli that portrayed either a complete or an incomplete version of the occluded shape. The dependent measure was the percentage of total errors that the birds committed to the complete foil. At the outset of training, the pigeons committed approximately 50% of total errors to the complete foil, but as training progressed, the percentage of errors to the complete foil rose. When the pigeons were given a second exposure to the initial set of stimuli, they committed 70% of total errors to the complete foil, suggesting that they now saw the complete foil as more similar to the occluded target than the incomplete foil. These results suggest that experience with 2-D images may facilitate amodal completion in pigeons, perhaps via perceptual learning.     

Pigeons and people select efficient routes when solving a one-way "traveling salesperson" task

The authors presented people (Experiment 1) and pigeons (Experiments 2 and 3) with a large number of 1-way traveling salesperson problems that consisted of 3, 4, and 5 identical stimuli (nodes) on a computer monitor. The sequence of nodes that each traveler selected was recorded, and the distance of the route was subsequently determined. The routes the pigeons and people selected were reliably more efficient than those used by a Monte Carlo model given the same problems. The pigeons' routes were significantly less efficient than a nearest neighbor model of performance, however. In Experiment 3, pigeons were required to select a route that was within the top 33% of all possible solutions for a given problem. The pigeons' solutions were significantly more efficient than those observed in Experiment 2, in which the behavioral criterion was not imposed. The mechanisms that pigeons and people may have been using to solve the traveling salesperson problems are discussed.     

Intrahemispheric sex differences in the functional representation of language and praxic functions in normal individuals

Kimura (1980, The Behavioral and Brain Sciences, 3, 240-241; 1983, Canadian Journal of Psychology, 37, 19-35; 1987, Canadian Psychology, 28, 133-147) recently proposed that there are intrahemispheric sex differences in the organization of particular language and praxic functions such that in females these functions are more focally represented. This hypothesis, as well as supporting data, was derived from research with brain-injured subjects. The purpose of the present study was to test the utility of using dual-task methodology for investigating sex-related variation in intrahemispheric functional organization in normal individuals. Women were found to show greater interference than men on concurrent tasks of language and right-hand finger tapping. In support of Kimura's model, the present findings yielded evidence suggestive of intrahemispheric sex differences in the "functional distance" between language and praxic functions within the left hemisphere of normal individuals.     

Correspondence

The American Journal of Psychoanalysis -     

An examination of the continuous distractor task and the “long-term recency effect”

The continuous distractor task has yielded a so-called "long-term recency effect" that appears to call into question the dual-storage explanation of serial position effects in free recall. In this study, we show that the "long-term recency effect" is really a short-term storage effect, resulting from adaptation to the repeated presentation of a particular type of distractor throughout the list. This adaptation, a time-sharing process, permits short-term storage to carry out its normal functions. Experiment 1 shows that an appropriate postlist distractor task does in fact eliminate the "long-term recency effect." This finding supports the assertion that the effect is a product of short-term storage. Experiment 2 demonstrates the benefits and costs of the time-sharing process, relative to standard free recall, for both long-term and short-term storage. The findings support the time-sharing hypothesis. Experiment 3 replicates Experiment 2, with a change in procedure that rules out output interference as a mechanism responsible for the results of Experiment 2. Data are also presented on the development of the adaptation over trials. It is concluded that the adaptation and time-sharing processes need to be included in the dual-storage model of short-term storage.     

A clarification of frequency effects in children’s discrimination learning

Memory & Cognition - Three experiments were conducted to assess the effects of certain stimulus variables on children’s discrimination learning. In general, it was found that word...