Choking under pressure and working memory capacity: When performance pressure reduces fluid intelligence

Recent findings (Beilock & Carr, 2005) have demonstrated that only individuals with a high working memory capacity (WMC) “choke under pressure” on math problems with high working memory demands. This suggests that performance pressure hinders those who are the most qualified to succeed, because it consumes the WMC they usually rely on to achieve superior performance. This puts into question the use of performance in high-pressure situations as a means of distinguishing individuals with lesser or greater WMC potentials. While addressing several limitations of past research, we offer evidence that such choking (1) occurs only in individuals with high WMC, because of their anxiety-ridden perceptions of high-stakes situations, and (2) is not confined to tasks involving acquired skills and knowledge, but encompasses fluid reasoning abilities or intelligence (Gf). These findings have strong implications for assessments of people’s intellectual capacities in academic, clinical, work, and research settings.     

NMDA and muscarinic receptors of the nucleus accumbens have differential effects on taste memory formation

Animals recognize a taste cue as aversive when it has been associated with post-ingestive malaise; this associative learning is known as conditioned taste aversion (CTA). When an animal consumes a new taste and no negative consequences follow, it becomes recognized as a safe signal, leading to an increase in its consumption in subsequent presentations (attenuation of neophobia, AN). It has been shown that the nucleus accumbens (NAcc) has an important role in taste learning. To elucidate the involvement of N-methyl-D-aspartate (NMDA) and muscarinic receptors in the NAcc during safe and aversive taste memory formation, we administrated bilateral infusions of DL-2-amino-5-phosphonopentanoic acid (APV) or scopolamine in the NAcc shell or core respectively. Our results showed that pre-training injections of APV in the NAcc core and shell disrupted aversive but not safe taste memory formation, whereas pre-training injections of scopolamine in the NAcc shell, but not core, disrupted both CTA and AN. These results suggest that muscarinic receptors seem to be necessary for processing taste stimuli for either safe or aversive taste memory, whereas NMDA receptors are only involved in the aversive taste memory trace formation.     

Pilot programs in newborn screening

The term "pilot study" has been used over the years to describe the evaluation of the many elements involved in deciding whether a proposed condition should be added to a newborn screening (NBS) panel, and until recently, was unilaterally used to describe the evaluation of the assay to be used before the condition was officially adopted by a state for its newborn screening panel. Since Guthrie's introduction of screening for PKU, each time a new condition was added to the panel, the screening assay itself was validated through a population-based trial, in which the test was performed with de-identified samples to avoid association between the test result and the infant. This is considered by the laboratory as the "pilot phase" of adding a new condition. To advance the science of NBS, especially to accommodate new technologies that may provide new types of information (genetic versus physiological) for each new condition, pilot programs are essential. Involvement of the clinical community serves to improve these evaluations and provides the needed clinical validation of decisions made as a result of it. This paper describes the historical context of pilot programs in population-based NBS that utilize laboratory-based markers as indicators of concern; specifically, three applications that demonstrate different approaches to the use of pilots in adding conditions to a NBS panel are described.     

Capsaicin-sensitive afferent vagal fibers are involved in concurrent taste aversion learning

Taste aversion learning (TAL) is a type of learning characterized by rejection of a gustatory/flavor stimulus as a consequence of its pairing with visceral discomfort and malaise. TAL can be established in the laboratory by two different behavioral procedures, concurrent or sequential. Neural mechanisms of these learning modalities remain to be elucidated, but several studies have discussed the implication of various anatomical structures, including the vagus nerve. The aim of this study was to examine the role of capsaicin-sensitive vagal afferent fibers in concurrent (Experiment 1) and sequential (Experiment 2) TAL in Wistar rats. Results showed that perivagal administration of capsaicin (1mg of capsaicin dissolved in 1ml of vehicle (10% Tween 80 in oil)) blocked acquisition of concurrent but not sequential TAL. These data support the hypothesis of two different modalities of TAL mediated by distinct neurobiological systems, with vagal nerve participation only being essential in concurrent TAL.     

Access to HIV care among migrant Africans in Britain. What are the issues?

In the UK, substantial numbers of new HIV diagnoses are within migrant communities, especially African communities. Current surveillance shows that despite health promotion efforts and advances in therapy these communities are accessing HIV care late. This paper explores the issues influencing the access and uptake of HIV care by migrant Africans in Britain. Using Kleinman's model of health care systems (Kleinman, 1980) as a theoretical framework, we highlight the importance of placing health within its broader context if we are to make significant improvement to the health of HIV-infected Africans in Britain.     

Egocentric search for disappearing objects in domestic dogs: evidence for a geometric hypothesis of direction

In several species, the ability to locate a disappearing object is an adaptive component of predatory and social behaviour. In domestic dogs, spatial memory for hidden objects is primarily based on an egocentric frame of reference. We investigated the geometric components of egocentric spatial information used by domestic dogs to locate an object they saw move and disappear. In experiment 1, the distance and the direction between the position of the animal and the hiding location were put in conflict. Results showed that the dogs primarily used the directional information between their own spatial coordinates and the target position. In experiment 2, the accuracy of the dogs in finding a hidden object by using directional information was estimated by manipulating the angular deviation between adjacent hiding locations and the position of the animal. Four angular deviations were tested: 5, 7.5, 10 and 15°. Results showed that the performance of the dogs decreased as a function of the angular deviations but it clearly remained well above chance, revealing that the representation of the dogs for direction is precise. In the discussion, we examine how and why domestic dogs determine the direction in which they saw an object disappear.     

Neural bases of binocular rivalry

During binocular rivalry, conflicting monocular images compete for access to consciousness in a stochastic, dynamical fashion. Recent human neuroimaging and psychophysical studies suggest that rivalry entails competitive interactions at multiple neural sites, including sites that retain eye-selective information. Rivalry greatly suppresses activity in the ventral pathway and attenuates visual adaptation to form and motion; nonetheless, some information about the suppressed stimulus reaches higher brain areas. Although rivalry depends on low-level inhibitory interactions, high-level excitatory influences promoting perceptual grouping and selective attention can extend the local dominance of a stimulus over space and time. Inhibitory and excitatory circuits considered within a hybrid model might account for the paradoxical properties of binocular rivalry and provide insights into the neural bases of visual awareness itself.     

Hypertension reduction through forgiveness training

The objective of this study was to determine if patients with diagnosed stage-1 hypertension could benefit by a forgiveness training program to achieve measurable reductions in anger expression and blood pressure. Twenty-five participants were randomly divided into wait-listed control and intervention groups. The control group monitored blood pressure while the intervention group participated in an 8-week forgiveness training program. At the end of eight weeks, the wait listed group became an intervention group. Those who received forgiveness training achieved significant reductions in anger expression when compared to the control group. While reductions in blood pressure were not achieved by all the participants, those participants who entered the program with elevated anger expression scores did achieve significant reductions in blood pressure. It is suggested that forgiveness training may be an effective clinical intervention for some hypertensive patients with elevated levels of anger.