Delayed alternation in the pigeon

Pigeons were studied in a delayed-response task requiring alternation of key pecks on two response keys. Blackouts of from 1 to 10 sec intervened between successive choices on the two keys.

The following results were obtained: (1) Birds performed at well above chance accuracy on all the delays tested. Accuracy was generally lowest at 1- and 10-sec delays. (2) Overt postural orientations during the delay interval appeared to mediate accurate key-pecking behavior. (3) The shape of the delay vs. accuracy function was discussed in terms of the possibly confounding influences of (a) stimulus “trace” variables, and (b) aversive effects of the time outs produced by incorrect responding.

     

Concurrent generalization gradients for food-controlled and shock-controlied behavior

In the presence of a bright light, monkeys were trained to press a lever to avoid shock and to pull a chain for food reward. After gradients of generalization to other light intensities had been determined for each response, gradients were subsequently secured after training in a brightness discrimination and under several free-shock conditions. The following results were obtained: (1) Generalization gradients prior to discrimination training were much steeper for the food-controlled response than for the shock-controlled response. This finding was confirmed in another study in which rats served as subjects. (2) After discrimination training, both gradients became much steeper, but the avoidance gradient still showed more generalized responding than that of reward. (3) After a period of continuous testing with all the different test intensities, the two gradients became even steeper. In addition, differences between the two gradients virtually disappeared. (4) The intermittent delivery of free shocks during a previously non-shocked light intensity radically affected the shape of the avoidance gradient, just as the addition of an avoidance contingency did during the same, previously non-shocked, light intensity.     

Heterogeneity of Incentives for Physical Activity and Self-Efficacy in Highly Active and Moderately Active Women Exercisers

The purpose of this investigation was to examine whether persons exercising 2 times per week or less versus 3 times per week or more, with intentions to maintain current level of activity form a homogenous group in terms of motivational features. A group of 86 women recruited from local fitness clubs reported on their exercise incentives, self-efficacy, exercise behavior, and exercise intentions. A discriminant function analysis revealed that self-efficacy and incentives for stress reduction and mental health discriminated highly active from moderately active women. The implications of these findings are discussed in terms of stage theory and research in exercise adherence.     

Personality factors of individuals who survive traumatic experiences without professional help

This is a study of the personality resources that enable certain individuals to cope successfully with traumatic experiences without planned psychotherapeutic intervention. A survey of 40 trauma-surviving respondents reveals some common positive developmental and psychosocial factors. Also, five cases are described who experienced serious trauma, three of them living successful lives and two remaining disabled. The biological predisposition and the specific interaction of ones nature and nurture leading toward resolution of traumatic experiences are discussed. Individuals who have survived Posttraumatic Stress Disorder should be studied further within a psychobiological framework.     

Correlates of Depressive Disorders in the Quebec General Population 6 to 14 Years of Age

There are relatively few community-based epidemiological studies in which correlates of depressive disorders were identified through multivariate analyses in children and adolescents aged 6--14 years. Moreover, several family characteristics (e.g., parent-child relationship) have never been explored in this regard. The purpose of this study was twofold. Using data from the Quebec Child Mental Health Survey, it sought: (1) to identify psychosocial correlates associated with depressive disorder in two age-groups (6--11 and 12-14 years) according to informant (child/adolescent, parent); and (2) to interpret the relative importance of correlates by ranking variables according to strength and consistency of association across age-groups. Logistic regression models show correlates to be inconsistent across informants. The ranking of correlates indicates a major contribution of only-child status/ordinal position, parent's major depressive disorder, stressful family events, and parent-child relationship, thereby supporting the hypothesis of the relevance of family context in the development of depression.     

Integrating Integrity: The Organizational Translation of Policies on Research Integrity

Science and Engineering Ethics - Responsible conduct of research and research integrity has become a key concern in both research policy and public media resulting in a number of soft law...     

Distributed Connectionist Models in Social Psychology

Distributed connectionist models of mental representation (also termed PDP or parallel distributed processing, or ANN or artificial neural networks) constitute a fundamental alternative to the associative or schematic models that have been much more prevalent in social psychology. A connectionist model is made up of a large number of very simple processing units, richly interconnected and able to send signals to each other depending on their momentary activation levels. No individual processing unit represents a meaningful concept; instead, overall patterns of activation hold representational meaning. This article emphasizes the novel properties of connectionist representation that might appeal to theorists and researchers in social psychology, including their context sensitivity and flexibility, ability to represent prototypes and exemplars within a single network, and ability to determine whether a stimulus is familiar even before the stimulus can be identified or categorized.     

How does interhemispheric communication in visual word recognition work? Deciding between early and late integration accounts of the split fovea theory

It has recently been shown that interhemispheric communication is needed for the processing of foveally presented words. In this study, we examine whether the integration of information happens at an early stage, before word recognition proper starts, or whether the integration is part of the recognition process itself. Two lexical decision experiments are reported in which words were presented at different fixation positions. In Experiment 1, a masked form priming task was used with primes that had two adjacent letters transposed. The results showed that although the fixation position had a substantial influence on the transposed letter priming effect, the priming was not smaller when the transposed letters were sent to different hemispheres than when they were projected to the same hemisphere. In Experiment 2, stimuli were presented that either had high frequency hemifield competitors or could be identified unambiguously on the basis of the information in one hemifield. Again, the lexical decision times did not vary as a function of hemifield competitors. These results are consistent with the early integration account, as presented in the SERIOL model of visual word recognition.     

Conflict monitoring and feature overlap: Two sources of sequential modulations

Recent findings demonstrating that the Simon effect diminishes when the preceding trial is a noncorresponding trial led researchers to develop two alternative accounts. The conflict monitoring account argues that the automatic activation from stimulus location information is under the regulation of a control mechanism, which adjusts the level of activation depending on conflict in the preceding trial. In contrast, the feature integration account holds that sequential modulations of the Simon effect can be attributed to the integration of stimulus and response features into event files. Previous research demonstrated a potential contribution to sequential modulations from both mechanisms. We use a four-choice task to extend these findings and to investigate the exact nature of the feature overlap effects. Both conflict monitoring and feature overlap effects were found to contribute to sequential modulations. However, the feature overlap effects did not conform to predictions of the feature integration account. We argue that the feature overlap effects are accounted for better by strategic shortcuts in response selection.