Auditory orienting of attention: Effects of cues and verbal workload with children and adults

The use of tone cues has an improving effect on the auditory orienting of attention for children as for adults. Verbal cues, on the contrary, do not seem to orient attention as efficiently before the age of 9 years. However, several studies have reported inconsistent effects of orienting attention on ear asymmetries. Multiple factors are questioned, such as the role of verbal workload. Indeed, the semantic nature of the dichotic pairs and their load of processing may explain orienting of attention performance. Thus, by controlling for the role of verbal workload, the present experiment aimed to evaluate the development of capacities for the auditory orienting of attention. Right-handed, 6- to 12-year-olds and adults were recruited to complete either a tone cue or a verbal cue dichotic listening task in the identification of familiar words or nonsense words. A factorial design analysis of variance showed a significant right-ear advantage for all the participants and for all the types of stimuli. A major developmental effect was observed in which verbal cues played an important role: they allowed the 6- to 8-year-olds to improve their performance of identification in the left ear. These effects were taken as evidence of the implication of top-down processes in cognitive flexibility across development.     

On perturbation and pattern coexistence in postural coordination dynamics

In studies of postural control, investigators have used either experimentally induced perturbations to stance or unperturbed stance. The distinction between perturbed and unperturbed stance has gained renewed importance in the context of inphase and antiphase coordination of the hips and ankles. Several contributions have replicated the findings published over the past decade, suggesting the possibility of a unified view of postural control. However, any proposed unified view depends on how so called perturbed and unperturbed are defined. The authors argue that, to date, there is no explicit and general definition of those terms. The main reason is that all perturbations are relative and depend on appropriate frames of reference for perception and action. Arguments about empirical or theoretical unification of perturbed and unperturbed stance are premature.     

Crawling is associated with more flexible memory retrieval by 9-month-old infants

In the present experiment, we used a deferred imitation paradigm to explore the effect of crawling on memory retrieval by 9-month-old human infants. Infants observed an experimenter demonstrate a single target action with a novel object and their ability to reproduce that action was assessed after a 24-hr delay. Some infants were tested with the demonstration stimulus in the demonstration context and some infants were tested with a different stimulus in a different context. Half of the infants in each test condition were crawling at the time of participation and half were not. Both crawling and non-crawling infants exhibited retention when tested with the demonstration stimulus in the demonstration context, but only infants who were crawling by 9 months of age exhibited retention when tested with a different stimulus in a different context. These findings demonstrate that the onset of independent locomotion is associated with more flexible memory retrieval during the first year of life.     

Verbal,mathematics, and physical education self-concepts and achievements: An extension and test of the Internal/External Frame of Reference Model

ObjectivesThe Internal/External Frame of Reference Model (I/E model; e.g., Marsh, 1986) posits that verbal achievement (Ach) produces a lower mathematics self-concept (SC) and that, conversely, mathematics Ach fosters a lower verbal SC after controlling for prior Ach in each domain. The present study extended this model by adding another school subject that has not been previously investigated, namely physical education (PE). The central goal was to verify whether Ach in PE positively or negatively predicts academic SC in the mathematics and verbal domains.DesignProspective study over one school year.MethodsParticipants were 451 French high school students (mean age = 13.5). Ach scores in mathematics, French and PE were gathered at the beginning of the school year. At the end of this one, students completed a questionnaire to assess their SC in the three school subjects. Results: Structural Equation Modelling results revealed, according to the I/E model, negative paths between mathematics Ach and verbal SC, and between verbal Ach and mathematics SC. Results also revealed singular relationship patterns between the two traditional school subjects and PE. A positive path between PE Ach and mathematics SC was observed whereas the path with the verbal SC was non-significant.ConclusionPE could have benefits to increase SC in other school subject such as mathematics. Broader implications of results for the I/E model are discussed.     

The Prevalence of Spirituality, Optimism, Depression, and Fatalism in a Bi-ethnic Stroke Population

To provide insight into the reduced post-stroke all-cause mortality among Mexican Americans, we explored ethnic differences in the pre-stroke prevalence of (1) spirituality, (2) optimism, (3) depression, and (4) fatalism in a Mexican American and non-Hispanic white stroke population. The Brain Attack Surveillance in Corpus Christi (BASIC) project is a population-based stroke surveillance study in Nueces County, Texas. Seven hundred ten stroke patients were queried. For fatalism, optimism, and depression scales, unadjusted ethnic comparisons were made using linear regression models. Regression models were also used to explore how age and gender modify the ethnic associations after adjustment for education. For the categorical spirituality variables, ethnic comparisons were made using Fisher's exact tests. Mexican Americans reported significantly more spirituality than non-Hispanic whites. Among women, age modified the ethnic associations with pre-stroke depression and fatalism but not optimism. Mexican American women had more optimism than non-Hispanic white women. With age, Mexican American women had less depression and fatalism, while non-Hispanic white women had more fatalism and similar depression. Among men, after adjustment for education and age, there was no ethnic association with fatalism, depression, and optimism. Spirituality requires further study as a potential mediator of increased survival following stroke among Mexican Americans. Among women, evaluation of the role of optimism, depression, and fatalism as they relate to ethnic differences in post-stroke mortality should be explored.     

Role of the sympathetic nervous system in cerebrovascular responses to air-jet stress in rats

This study examined the role of sympathetic nerves in the control of cerebral hemodynamics during air-jet stress. In adult male Sprague-Dawley rats, blood flow velocity (pulsed Doppler) was measured in both internal carotid arteries 1 week after excision of one superior cervical ganglion. Blood pressure (BP) and carotid blood flows (CBFs) were simultaneously recorded during exposure to air-jet stress. In 5 out of 13 rats, stress was applied after β(2)-adrenoceptor blockade with ICI 118551 (0.4 mg/kg, then 0.2 mg/kg/h, i.v). Stress evoked an immediate rise in BP, CBFs, and vascular conductances. Vasodilatation was much larger on the denervated side than on the intact side (mean ± SEM: 78 ± 7 versus 19 ± 4%; P < 0.02) and lasted about 10 s. Thereafter, blood flows returned to or near normal and showed parallel variations while BP remained elevated. There was, therefore, a net vasoconstriction on both sides. In ICI 118551-treated rats, the initial vasodilatation was not significantly reduced on the denervated side (64 ± 4%), but the subsequent vasoconstriction was enhanced (P < 0.05) on both sides. In conclusion, air-jet stress evokes an immediate, short-lasting vasodilatation through a mechanism unrelated to β(2)-adrenoceptor stimulation. Sympathetic nerves powerfully limit this phenomenon, and thus contribute to protect the cerebral circulation from stress-induced BP surges.