The effects of post-encoding stress on recognition memory: examining the impact of skydiving in young men and women

Prior studies have indicated that post-encoding stress can protect memories from the effects of forgetting, and this has been taken as evidence that stress facilitates memory consolidation. However, it is not known whether stress acts by directly influencing the strength of the underlying memories or whether it influences the generation process that plays a critical role in tests such as free recall. To address this issue, we examined the effects of stress produced by skydiving on recognition memory for negative and neutral pictures. Relative to a non-stress control condition, post-encoding stress in males was found to increase recognition memory for neutral pictures. However, stress was not found to improve recognition for emotional pictures, nor was it found to influence recognition memory in female participants. Additional analysis of recognition performance suggested that stress increased familiarity-based recognition rather than recollection. This study indicates that stress can improve familiarity-based recognition, thus showing that stress directly increases the strength of the underlying memories.     

Modulation of N400 in chronic non-fluent aphasia using low frequency Repetitive Transcranial Magnetic Stimulation (rTMS)

Low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) has previously been applied to language homologues in non-fluent populations of persons with aphasia yielding significant improvements in behavioral language function up to 43 months post stimulation. The present study aimed to investigate the electrophysiological correlates associated with the application of rTMS through measurement of the semantic based N400 Event-related brain potentials (ERP) component. Low frequency (1 Hz) rTMS was applied to the anterior portion of the homologue to Broca’s area (pars triangularis), for 20 min per day for 10 days, using a stereotactic neuronavigational system. Twelve non-fluent persons with aphasia, 2-6 years post stroke were stimulated. Six participants were randomly assigned to receive real stimulation and six participants were randomly assigned to receive a blind sham control condition. ERP measures were recorded at baseline, 1 week and 2 months subsequent to stimulation. The findings demonstrate treatment related changes observed in the stimulation group when compared to the placebo control group at 2 months post stimulation indicating neuromodulation of N400 as a result of rTMS. No treatment related changes were identified in the stimulation group, when compared to the sham group from baseline to 1 week post stimulation. The electrophysiological results represent the capacity of rTMS to modulate neural language networks and measures of lexical-semantic function in participants with non-fluent aphasia and suggest that time may be an important factor in brain reorganization subsequent to rTMS.     

Word recognition across orthographies: Another look at the interaction between context and degradation

Abstract

The performance of English and Spanish subjects was examined in two experiments using a lexical decision task in which the effects of semantic priming and stimulus degradation were systematically varied. The Orthographic Depth Hypothesis predicts that priming and degradation will interact in the orthographically “deep” language (English) but not in the “shallow” one (Spanish). In the first experiment, the two factors were found to interact in a similar way in both English and Spanish groups. In the second experiment, in which only Spanish subjects participated, the interaction was again present but only in those subjects who showed an overall facilitation effect on primed words. The results are consistent with the use of the so-called “direct” route in Spanish and are at variance with other previous findings which have suggested that reading in shallow orthographies occurs via the “indirect” phonological route. There was also evidence that nonword rejection times were slower in Spanish subjects and that the performance of the two groups was affected differently by the different types of neutral baseline primes (asterisks or unrelated words). Possible interpretations of these performance variations are briefly discussed.     

Applied Research and Zoo Education: The Evolution and Evaluation of a Public Talks Program using Unobtrusive Video Recording of Visitor Behavior

ABSTRACT

The provision of high-quality conservation education has become a priority for modern zoos. This can be delivered in a number of differing ways to account for differences in learning styles and prior knowledge of zoo visitors. At Chester Zoo (United Kingdom), a team of full-time and highly trained interpreters (known as presenters) deliver a diverse public talks program every day of the year. Although these talks attract a large audience, little was understood about their impact on the visitor. As a result, an extensive, unobtrusive study using video recording equipment was undertaken to assess visitor behavior. Results suggest that visitor attentiveness was much higher among those individuals who found themselves in a better viewing position (where they could see the animal and presenter). Visitors who were in poor-visibility positions showed less attention than visitors who were observed under control conditions, without an accompanying talk, indicating a high environmental component to learning potential. When interactive elements were included in a talk (such as an animal feed or enrichment activity) attentiveness was dramatically increased. More crucially, however, was that during talks where there was no interactivity or animals were inactive, attentiveness fell to below control levels, suggesting that heightened visitor expectations created by the anticipation for the talk were not being met—a serious barrier to learning. These findings offer a series of measures that can be taken to improve the educational impact of a zoo talks program whilst, at the same time, providing a better quality experience for zoo visitors.     

Competing perspectives on deviance

This paper presents an assessment of the theoretical conflicts and debates within the sociology of deviance over the past two decades. It delineates the epistemological and theoretical confusion that currently characterize the field, and points out some of the dangers that this factionalization entails.     

Immediate Movement History Influences Reach-to-Grasp Action Selection in Children and Adults

The authors review studies of mentally simulated movements. In automatic or cyclical movements, actual and motor imagery (MI) durations are similar. When athletes simulate only dynamic phases of movement or perform MI just before competing, however, environmental and time constraints lead to an underestimation of actual duration. Conversely, complex attention-demanding movements take longer to image. Finally, participants can modify the speed of MI voluntarily when they receive specific instructions. To complete the available data, the authors compared imagined and actual durations in tennis and gymnastics. Results showed systematic and disproportionate overestimation of actual duration. The authors found a relationship between complex motor skills and MI duration. They discuss the factors leading to over- and underestimation and the hypotheses that could be tested.     

A Multilevel Nonlinear Profile Analysis Model for Dichotomous Data

This study linked nonlinear profile analysis (NPA) of dichotomous responses with an existing family of item response theory models and generalized latent variable models (GLVM). The NPA method offers several benefits over previous internal profile analysis methods: (a) NPA is estimated with maximum likelihood in a GLVM framework rather than relying on the choice of different dissimilarity measures that produce different results, (b) item and person parameters are computed during the same estimation step with an appropriate distribution for dichotomous variables, (c) the model estimates profile coordinate standard errors, and (d) additional individual-level variables can be included to model relationships with the profile parameters. An application examined experimental differences in topographic map comprehension among 288 subjects. The model produced a measure of overall test performance or comprehension in addition to pattern variables that measured the correspondence between subject response profiles and an item difficulty profile and an item-discrimination profile. The findings suggested that subjects who used 3-dimensional maps tended to correctly answer more items in addition to correctly answering items that were more discriminating indicators of map comprehension. The NPA analysis was also compared with results from a multidimensional item response theory model.     

The Ontic and the Ontological in Heidegger's Philosophy of Technology: Response to Thomson

Iain Thomson's critique is persuasive on several points but not on the major issue, the relation of the ontological to the ontic in Heidegger's philosophy of technology. This reply attempts to show that these two dimensions of Heidegger's theory are closely related, at least in the technological domain, and not separate, as Thomson affirms. It is argued that Heidegger's evaluations of particular technologies, the flaws of which Thomson concedes, proceed from a flawed ontological conception.     

The role of the human extrastriate visual cortex in mirror symmetry discrimination: a TMS-adaptation study

The human visual system is able to efficiently extract symmetry information from the visual environment. Prior neuroimaging evidence has revealed symmetry-preferring neuronal representations in the dorsolateral extrastriate visual cortex; the objective of the present study was to investigate the necessity of these representations in symmetry discrimination. This was accomplished by the use of state-dependent transcranial magnetic stimulation, which combines the fine resolution of adaptation paradigms with the assessment of causality. Subjects were presented with adapters and targets consisting of dot configurations that could be symmetric along either the vertical or horizontal axis (or they could be non-symmetric), and they were asked to perform a symmetry discrimination task on the targets while fixating the center of the screen. TMS was applied during the delay between the adapter and the test stimulus over one of four different sites: Left or Right V1/V2, or left or right dorsolateral extrastriate cortex (DLO). TMS over both Left and Right DLO reduced the adaptation effect in detecting vertical and horizontal symmetry, although the Left DLO effect on horizontal symmetry and the Right DLO effect on both vertical and horizontal symmetry were present only when considering subjects who showed a behavioral adaptation effect in the baseline No-TMS condition. Application of TMS over the Left or Right V1/V2 did not modulate the adaptation effect. Overall, these data suggest that both the Left and Right DLO contain neuronal representations tuned to mirror symmetry which play a causal role in symmetry discrimination.     

Why so confident? The influence of outcome desirability on selective exposure and likelihood judgment

Previous studies that have directly manipulated outcome desirability have often found little effect on likelihood judgments (i.e., no desirability bias or wishful thinking). The present studies tested whether selections of new information about outcomes would be impacted by outcome desirability, thereby biasing likelihood judgments. In Study 1, participants made predictions about novel outcomes and then selected additional information to read from a buffet. They favored information supporting their prediction, and this fueled an increase in confidence. Studies 2 and 3 directly manipulated outcome desirability through monetary means. If a target outcome (randomly preselected) was made especially desirable, then participants tended to select information that supported the outcome. If made undesirable, less supporting information was selected. Selection bias was again linked to subsequent likelihood judgments. These results constitute novel evidence for the role of selective exposure in cases of overconfidence and desirability bias in likelihood judgments.