Presence/absence-sample matching by pigeons: divergent retention functions may result from the similarity of behavior during the absence sample and the retention interval

Divergent choose-absence retention functions typically found in pigeons following presence/absence-sample matching have been attributed to the development of a single-code/default coding strategy. However, such effects may result from adventitious differential responding to the samples. In Experiment 1, retention functions were divergent only when differential sample responding could serve as the basis for comparison choice. In Experiment 2, when pecking did not occur during the retention interval, a choose-absence bias was found, but when pecking occurred during the retention interval, a choose-presence bias resulted. In Experiment 3, positive transfer was found when a stimulus associated with the absence of pecking replaced the absence sample but not when a stimulus associated with pecking replaced the presence sample. Thus, presence/absence-sample matching may not encourage the development of a single-code/default coding strategy in pigeons.     

Divided attention during encoding and retrieval: differential control effects?

Previous studies have shown that divided attention (DA) during retrieval has little effect on recall of episodic memories, although DA during encoding has a large detrimental effect. One possible reason for this asymmetry is that stimulus presentation at encoding is under experimenter control, whereas retrieval operations and responses are under participant control. This experiment tested this possibility by presenting paired-associate word lists for learning and recall, either at a fixed 4-s rate or at a rate controlled by the participant. The results showed that the higher recall levels for DA at retrieval than for DA at encoding held under all combinations of experimenter and participant control. The implications of these results for a fuller understanding of encoding and retrieval processes are discussed.     

Glucocorticoid receptor interaction with Hsp90 remains unaltered after whole body hyperthermia

The influence of 41 degrees C whole body hyperthermic stress on glucocorticoid receptor (GR) association with 90-kDa heat shock protein (Hsp90) in the rat liver cytosol was examined. Total cytosolic GR and Hsp90 concentrations, as well as the amount of Hsp90 co-immunoprecipitated with the GR were determined by quantitative Western blotting using BuGR2 as anti-GR and AC88 as anti-Hsp90 monoclonal antibody. After exposure of the animals to the heat stress, the level of cytosolic Hsp90 increased, while its ratio to apo-receptor within non-activated GR heterooligomeric complexes remained unaltered. Therefore, the Hsp90 recruitment by the GR was not dependent on Hsp90 total cytosolic concentration.     

Attentional requirements for object-location priming

The purpose of the present experiments was to investigate whether a verbal and a spatial secondary task would disrupt priming for object-location associations. Symbols were placed one at a time in one of nine locations in a rectangle. Implicit memory was tested with a reaction time (RT) task. All symbols were placed in the same location of the rectangle across 10 trial blocks; then, all their locations were changed. Responses were made on the numeric keypad, which corresponded to the spatial locations used in the rectangle. A decrease in RTs across the first 10 trial blocks followed by an increase in RTs when the symbols changed locations would indicate priming for the associations. The results were that implicit memory for object-location associations was obtained under single-, but not under dual-task conditions. We have interpreted the results in terms of a working memory model that posits that implicit memory will suffer when cognitive resources are limited.     

Explicitly modeling the effects of aging on response time

Research into the effects of aging on response time has focused on Brinley plots. Brinley plots are constructed by plotting mean response times for older subjects against those for young subjects for a set of experimental conditions. The typical result is a straight line with a slope greater than 1 and a negative intercept. This linear function has been interpreted as showing that aging leads to a general slowing of cognitive processes. In this article, we show that the slope of the Brinley plot is actually a measure of the relative standard deviations of older versus young subjects’ response times; it is not a measure of general slowing. We examine current models of the effects of aging on mean response time and show how they might be reinterpreted. We also show how a more comprehensive model, Ratcliff’s diffusion model (1978), can account for Brinley plot regularities and, at the same time, provide an account of accuracy rates, the shapes of response time distributions, and the relative speeds of error and correct response times, aspects of the data about which models designed to account for Brinley plots are mute. We conclude by endorsing a research approach that applies explicit models to response time data in aging in order to use the parameters of the model to interpret the effects of aging.     

The role of recent life events in the onset of obsessive-compulsive disorder

Although many investigations into the onset of obsessive-compulsive disorder (OCD) suggest the occurrence of potential life events as triggering factors, such an association has not been well studied to date. The purpose of the present paper is to review the literature on OCD onset in order to determine whether OCD is triggered by recent life events, what specific events may serve as triggers, and the clinical and research implications of these factors. Overall, the available studies do not consistently support the theory that OCD is triggered by specific antecedent life events. However, there is a body of evidence to support the theory that the specific life events of pregnancy and birth of a child can trigger OCD. This apparent association has led to the investigation of certain neurohormonal factors, including changes in estrogen or oxytocin levels, that may be of etiopathogenetic significance in OCD. Confirming such associations may allow clinicians to provide more targeted preventive and therapeutic interventions.     

Piaget and Levy-Bruhl

Levy-Bruhl exerted a powerful influence, seldom considered, on Piaget. The Levy-Bruhlian thesis of a "pre-logical mentality" characterized by "mystical participation" is outlined, together with its initial reception. The first evidence of Piaget's interest in it dates from 1920, and when he began his studies of children's thinking he compared it with that of 'primitives," also adopting Levy-Bruhl's concept of "participation." By 1928 Piaget had elaborated a theory of the social foundations of different types of thought, which he regarded as also explaining the alleged similarity between the thinking of primitives and children. Both are subject to constraint, primitives by elders and children by parents and teachers. Logical as opposed to pre-logical thought was said to depend on cooperation in free social interaction. Piaget continued to maintain essentially the same views long after Levy-Bruhl himself had renounced the notion of pre-logicality.