Voluntary Control of Cognitive Activity in Preschool Children: Age-dependent Changes from Ages 3-4 to 4-5.

Background: Voluntary control of goal-directed behavior and mental activity in preschool children plays a key role in knowledge acquisition and future academic achievement. Studies of voluntary control have mainly concerned 6-8-year old children; much less is known about the ability to exercise voluntary control at early ages. Due to the high prognostic value of the level of development of voluntary control and heterogeneous development of their individual components, it seems actually useful to study age-related changes of these components in children from 3-4 to 4-5 years old.

Mechanism of Dyspnea during Exercise in Children with Corrected Congenital Heart Disease.

This study will evaluate cardiorespiratory and peripheral muscle function and their relationship with subjective dyspnea threshold after the surgical correction of congenital heart disease in children. Thirteen children with surgically repaired congenital heart disease were recruited. Each participant performed an incremental exercise test on a cycle ergometer until exhaustion.

Intracortical Directed Connectivity for Information Retention in Visual-Spatial Working Memory.

A group of 27 healthy young adults solved a task involving the working memory (WM) activation, consisting of the comparison between the spatial orientations of two sequentially presented square-wave luminance gratings. We investigated the effective (directed) connectivity patterns between the frontal and postcentral cortical regions related to the visual system. The connectivity was assessed using vector autoregression modeling of EEG.

[Anthropometric indicators of physical development and nutritional status employed in hygiene practice in Russia].

In the current review, we consider the main working methods of Russian hygienists to assess anthropometric indices using a) regional data on (populational) variability of the concerning measurements and b) unified reference data applicable in most regions. An analysis showed that in most cases, the regional standards are based on average values and variabilities derived from a local sample, which can not serve as a working normative. As a result, these so called "standards" do not provide information on how healthy children should develop, and the assessments inferred are difficult to integrate to draw a picture for the whole country.

The Role of Motor Activity in Insight Problem Solving (the Case of the Nine-Dot Problem).

Attempts to estimate the contribution made by motor activity to insight problem solving is hindered by a lack of detailed description of motor behavior. The goal of this study was to develop and put to the test a novel method for studying the dynamics of insight problem solving based on a quantitative analysis of ongoing motor activity. As a proper problem model, we chose the nine-dot problem (Maier, 1930), in which solvers had to draw a sequence of connected line segments.

Alpha-band functional connectivity during cued versus implicit modality-specific anticipatory attention: EEG-source coherence analysis.

The anticipation of future events based on a background experience is one of the main components of any goal-directed behavior. Anticipatory attention can be either voluntary (explicit) or involuntary (implicit). We presumed that these two types of anticipatory attention differed in terms of cortical functional organization.

Genes related to the metabolism of nutrients in the Kola Sami population.

Objectives: The environmental and life-style conditions of the Kola Sami could have influenced the population-specific frequencies of the AGXTProIILeu allele, and certain alleles of APOE and LCT genes, involved respectively, in the metabolism of animal proteins, lipids and milk sugar. Study Design. DNA samples were collected from the Sami population of Lovozero settlement (Murmansk Region) in 2005.

Activity of disaccharidases in arctic populations: evolutionary aspects disaccharidases in arctic populations.

Disorders of dietary sugar assimilation occur more often among native people of the Arctic then in temperate climate inhabitants. It is hypothesized that the limited variety of natural exogenous sugars in the Arctic, and their low content in the traditional diets of native northerners in accordance with a "protein-lipid" type of metabolism weakened selection, favoring diversity of disaccharidase enzymes.

[Neurophysiological mechanisms of voluntary attention: a review].

The review is focused on attention as behavior-controlling process. Neurophysiological, electrophysiological and neuropsychological studies of different brain structures during voluntary attention are analyzed. These data show that selective voluntary attention modulates activity of sensory specific cortical zones involved in relevant signal processing.

Elaboration of on-board automated training system.

Unlabelled: Long-term space flight requires regular controlling of crewmembers physical state and exercise training to prevent negative effect of microgravity. Considering a limited telecommunication we suppose on-board automated training system to become an effective alternative of on-earth mission teams.

The Purpose: to elaborate an expert system software permitting to automate the process of solution elaboration to estimate cosmonaut current psycho-physiological state and to form an individual program of physical training to prevent negative effects of long-term space flight.

[A. A. Ukhtomskiĭ's ideas in studies on the cognitive activity].

Experimental data on spatial and temporal organisation of the human EEG from birth to maturity, at resting and during cognitive activity, is presented. The data obtained is interpreted in light of a confirmation of the Ukhtomsky's ideas on the "functional working organ" appearing in the brain for realising cognitive processes. Role of the alpha-rhythm in formation of plastic intracortical neuronal network is elucidated.

Visual stimulus-dependent changes in interhemispheric EEG coherence in humans.

We analyzed the coherence of electroencephalographic (EEG) signals recorded symmetrically from the two hemispheres, while subjects (n = 9) were viewing visual stimuli. Considering the many common features of the callosal connectivity in mammals, we expected that, as in our animal studies, interhemispheric coherence (ICoh) would increase only with bilateral iso-oriented gratings located close to the vertical meridian of the visual field, or extending across it. Indeed, a single grating that extended across the vertical meridian significantly increased the EEG ICoh in normal adult subjects.

The effects of lesions to subcortical conducting pathways on the electrical activity of the human cerebral cortex.

Simultaneous assessment, during the neurorehabilitation process, of electroencephalographic and neurological data, along with computerized tomography and computerized emission tomography data from patients suffering from sequelae due to ischemic insult allowed the organic origin of a number of EEG phenomena to be identified. These studies showed that lesions to the conducting pathways between the cortex and subcortical structures due to circulatory pathology in the territory of the middle cerebral artery were accompanied by local changes in the electrical activity of the cortex, mainly in the form of polymorphic waves in the theta and delta frequency ranges, along with groups of theta oscillations. The nature of slow-wave oscillations depended on the extent of the lesions and the severity of the blood supply loss in the affected area.

EEG coherence changes during finger tapping in acallosal and normal children: a study of inter- and intrahemispheric connectivity.

The EEG inter- and intrahemispheric coherences (ICoh and HCoh) in the theta, alpha and beta bands were studied in an acallosal group (ACCG) of five children and a normal group of 30 sex- and age-matched children (NG) during resting and tapping conditions. Being functionally deficient, tapping in the ACCG was characterized by increased intertap intervals and variability (in right-hand tapping) and by variability together with decreased synchronization (in bimanual tapping). In the ACCG, frontal, central and parietal ICohs were shown to be smaller, while temporal ICohs were larger under all conditions (see also Koeda, T.

Dynamic character and age dependence of functional brain organization in attention.

Intrahemispheric functional organization was studied during a task expectancy period with special reference to attention mechanisms. The estimation of coherence of functionally identical rhythmic EEG components was made to characterize the intracortical integration. Several factors influencing the possibility to make an adequate prognosis and to realize it were varied.