Functional interaction of mGlu5 and NMDA receptors in aversive learning in rats

Metabotropic glutamate receptor 5 (mGlu5) has been implicated in a variety of learning processes and is important for inhibitory avoidance and conditioned taste aversion learning. MGlu5 receptors are physically connected with NMDA receptors and they interact with, and modulate, the function of one another in several brain regions. The present studies used systemic co-administration of an mGlu5 receptor positive allosteric modulator, 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB) and an NMDA receptor antagonist dizocilpine maleate (MK-801) to characterize the interactions of these receptors in two aversive learning tasks. Male Sprague-Dawley rats were trained in a single-trial step-down inhibitory avoidance or conditioned taste aversion task. CDPPB (3 or 10mg/kg, s.c.), delivered by itself prior to the conditioning trial, did not have any effect on performance in either task 48 h after training. However, CDPPB (at 3mg/kg) attenuated the MK-801 (0.2mg/kg, i.p.) induced learning deficit in both tasks. CDPPB also reduced MK-801-induced hyperactivity. These results underlie the importance of mGlu5 and NMDA receptor interactions in modulating memory processing, and are consistent with findings showing the efficacy of positive allosteric modulators of mGlu5 receptors in reversing the negative effects of NMDA receptor antagonists on other behaviors such as stereotypy, sensorimotor gating, or working, spatial and recognition memory.     

The United Nations Convention on the Rights of the Child: a basis for jus cogens prohibition of juvenile capital punishment in the United States

This article supports the position that the 1989 United Nations Convention on the Rights of the Child (CRC) articulates a prohibition of capital punishment of juveniles that now must be considered a norm of jus cogens. The article provides statistics and trends regarding juveniles who commit capital crimes and describes how the U.S. justice system handles such juveniles, including Eighth Amendment analyses of juvenile executions under the U.S. Constitution. The article also discusses community consensus regarding evolving standards of decency, describes international law on the capital punishment of juveniles, and outlines worldwide trends in juvenile executions. It then defines and describes the concepts of customary international law and jus cogens, applying these concepts to the problem of the execution of juveniles in the United States. The article concludes by suggesting that there is a moral imperative for universal prohibition of juvenile capital punishment and by speculating about the domestic effects of applying such a jus cogens norm in the United States.     

A refined model of sleep and the time course of memory formation

Research in the neurosciences continues to provide evidence that sleep plays a role in the processes of learning and memory. There is less of a consensus, however, regarding the precise stages of memory development during which sleep is considered a requirement, simply favorable, or not important. This article begins with an overview of recent studies regarding sleep and learning, predominantly in the procedural memory domain, and is measured against our current understanding of the mechanisms that govern memory formation. Based on these considerations, I offer a new neurocognitive framework of procedural learning, consisting first of acquisition, followed by two specific stages of consolidation, one involving a process of stabilization, the other involving enhancement, whereby delayed learning occurs. Psychophysiological evidence indicates that initial acquisition does not rely fundamentally on sleep. This also appears to be true for the stabilization phase of consolidation, with durable representations, resistant to interference, clearly developing in a successful manner during time awake (or just time, per se). In contrast, the consolidation stage, resulting in additional/enhanced learning in the absence of further rehearsal, does appear to rely on the process of sleep, with evidence for specific sleep-stage dependencies across the procedural domain. Evaluations at a molecular, cellular, and systems level currently offer several sleep specific candidates that could play a role in sleep-dependent learning. These include the upregulation of select plasticity-associated genes, increased protein synthesis, changes in neurotransmitter concentration, and specific electrical events in neuronal networks that modulate synaptic potentiation.     

Assessing psychologists' knowledge and attitudes toward near-death phenomena

Nina Thornburg's (1988) Near-Death Phenomena Knowledge and Attitudes Questionnaire was distributed to 326 randomly selected Illinois psychologists. Of 117 usable questionnaires received, the mean score for knowledge questions was 7.5 of a maximum score of 18. Respondents were most knowledgeable about near-death elements of peace, out-of-body transcendence, and tunnel/light phenomena. The mean score for the attitude portion of the instrument was 61.3 of a maximum score of 85 points for the most positive attitude. Seven percent of the respondents indicated having had a near-death experience, 19% indicated having counseling near-death experiencers, and 28% indicated having had personal contacts with an experiencer.     

Further validation of the Penny Beliefs Scale - Weapons

The Penny Beliefs Scale - Weapons (PBS-W) comprises of 36 items that measure young people’s beliefs about carrying and using weapons. It was designed to facilitate our understanding of weapons carrying and use. The PBS-W has excellent internal reliability (Cronbach’s alpha of .92), extremely good test-retest consistency (ICC = .83) and is significantly positively correlated with self-reported delinquency. In order to further demonstrate the utility of the PBS-W it was compared with other measures that would be expected to be associated with weapons carrying and use. The PBS-W, the Eysenck Personality Questionnaire (EPQ-R-SV), the Maudsley Violence Questionnaire (MVQ), the Barratt Impulsiveness Scale (BIS-11), and the Brief Measure of Sensation Seeking (SS2) were administered to 189 school pupils in South Wales, aged between 16 and 18 years. Results demonstrated that the PBS-W is significantly positively correlated with EPQ Psychoticism (P), violent cognitions, impulsivity, and sensation seeking. Multiple regressions, controlling for gender and impression management (EPQ-Lie), showed that violent cognitions predicted beliefs about carrying and using weapons above and beyond P, sensation seeking and impulsivity. These findings suggest that violent cognitions are the single most powerful predictors of positive beliefs about carrying and using weapons.     

The Effects of Single- Versus Multiple-Exemplar Training on Vocal Identification of Artists’ Styles

The purpose of the present study was to assess the effects of single- versus multiple-exemplar training with several artists’ paintings on graduate students’ stimulus generalization to novel paintings by the same artists. Six graduate students participated in this study. Participants studied decks of cards that depicted images of paintings by six different artists. Multiple-exemplar decks included three exemplars of three artists for a total of nine cards, and single-exemplar decks included single exemplars of three artists for a total of three cards. Participants “tested out” when ready following independent study with each deck and were required to score 100 % correct in order to move on to a generalization probe, during which participants were presented with novel exemplars. Overall, four of six participants performed better on the generalization probe after multiple-exemplar training, though in the case of three participants, only to a slight degree. These modest effects suggest that multiple-exemplar training may facilitate stimulus generalization, but that studying with single exemplars may allow for stimulus generalization as well.     

Pitch and pitch change interact in auditory displays

Designing auditory displays requires understanding how different attributes of sound are processed. Operators must often listen to a particular stimulus dimension and make control actions contingent on the auditory information. Three experiments used a selective-listening paradigm to examine interactions between auditory dimensions. Participants were instructed to attend to either relative pitch or direction of pitch change of dynamic stimuli. With vertically arranged keypress responses, reactions to both dimensions showed stimulus-response compatibility effects, indicating that pitch is treated spatially. Direction of pitch change affected responses to pitch; level of pitch more strongly affected responses to pitch change. To reduce deleterious effects of irrelevant pitch information, auditory display designers can restrict the pitch range used to display dynamic data.     

Intellectual functioning in adults with ADHD: a meta-analytic examination of full scale IQ differences between adults with and without ADHD

Although attention has been given to the intellectual functioning of children with attention-deficit/hyperactivity disorder (ADHD) relative to their non-ADHD peers, few studies have examined intellectual functioning in adults with ADHD. The purpose of the current investigation was to examine differences in intellectual ability between adults with and without ADHD via a meta-analytic review. Of the 33 studies meeting inclusion criteria, primary analyses focused on 18 studies representing 1,031 adults with ADHD and 928 non-ADHD, nonclinical comparison adults and containing Wechsler Adult Intelligence Scale (WAIS; D. Wechsler, 1955, 1981, 1994) Full Scale IQ scores or estimates. A significant effect was found such that adults with ADHD scored lower than non-ADHD adults on WAIS intelligence tests. However, this difference was small and not clinically meaningful. The presence of several moderators reflecting characteristics of the ADHD samples and study methodology suggested that only a subset of adults with ADHD (e.g., those with comorbid disorders) may experience lower general intellectual ability relative to non-ADHD comparison adults. Implications of the findings for clinical and research settings are presented as well as suggestions for improving methodology and reporting in future research.     

Equating tasks and sustaining attention in children and adults: the methodological and theoretical utility of d' matching

The present study develops a method to create task equivalency for children and adults in vigilance research. Experiment 1 employed the signal detection index of perceptual sensitivity (d') to calibrate vigilance tasks for 32 children (ages 7-8) and 32 adults. The results of Experiment 1 suggest that task equivalency across groups can be attained, and a vigilance decrement was observed for children. In Experiment 2, the task parameter of event rate was manipulated across two vigils. Again, 32 children (ages 7-8) and 32 adults participated. The results suggest that a reverse event rate effect emerged for both children and adults. In addition, developmental differences in response to the event rate manipulation and with respect to the vigilance decrement emerged: Children benefited less from the manipulation and were more likely to demonstrate a vigilance decrement than were adults. No developmental differences emerged for the sensitivity decrement. The results are explained with reference to how task demands interact with participant arousal, and implications for development and for future research are discussed.