Spatiotemporal Dependency of Age-Related Changes in Brain Signal Variability

Recent theoretical and empirical work has focused on the variability of network dynamics in maturation. Such variability seems to reflect the spontaneous formation and dissolution of different functional networks. We sought to extend these observations into healthy aging. Two different data sets, one EEG (total n = 48, ages 18-72) and one magnetoencephalography (n = 31, ages 20-75) were analyzed for such spatiotemporal dependency using multiscale entropy (MSE) from regional brain sources. In both data sets, the changes in MSE were timescale dependent, with higher entropy at fine scales and lower at more coarse scales with greater age. The signals were parsed further into local entropy, related to information processed within a regional source, and distributed entropy (information shared between two sources, i.e., functional connectivity). Local entropy increased for most regions, whereas the dominant change in distributed entropy was age-related reductions across hemispheres. These data further the understanding of changes in brain signal variability across the lifespan, suggesting an inverted U-shaped curve, but with an important qualifier. Unlike earlier in maturation, where the changes are more widespread, changes in adulthood show strong spatiotemporal dependenc

THE EFFECT OF DAILY PHYSICAL EDUCATION LESSONS ON HUNGARIAN STUDENT'S PHYSICAL ACTIVITY LEVELS AND BODY COMPOSITION

Lifestyle, physical activity level and nutritional habits as well as environmental factors are having a greater and greater detrimental effect on the health of various populations. In the present study we systematically researched the physical status of schoolchildren. It is well known that as children grow up, the amount of spontaneous physical activity they perform decreases as they have more mental tasks to do these negative factors can be offset with daily physical education. We measured children participating in physical education on a daily basis, consisting of 5th (10-11 years old) and 9th (14-15 years old) grade students and control groups of 4th (9-10 years old) and 8th (13-14 years old) grade students, respectively, for a total of 196 persons (94 girls and 102 boys). Habitual physical activity was obtained with Actigraph, (GT1M/GT3X) and body fat percentage was calculated from anthropometrical measurements. As expected, we were able to observe a linear correlation between the physical activity levels and the body composition of the participants. The more time the subjects spent performing MVPA (Moderate and Vigorous Physical Activity), the less body fat they had. The recommended MVPA is a minimum of one hour per day, but these Hungarian children had two hours of MPVA per day. Our results lead us to conclude that ninety minutes of additional physical education per week for 7-8 months cannot be considered sufficient for a full impact analysis nor for schoolchildren’s physical activity needs or body composition, though an increase in the amount of time spent in physical education classes shows beneficial effects for these children

THE EFFECT OF DAILY PHYSICAL EDUCATION LESSONS ON HUNGARIAN STUDENT'S PHYSICAL ACTIVITY LEVELS AND BODY COMPOSITION

Lifestyle, physical activity level and nutritional habits as well as environmental factors are having a greater and greater detrimental effect on the health of various populations. In the present study we systematically researched the physical status of schoolchildren. It is well known that as children grow up, the amount of spontaneous physical activity they perform decreases as they have more mental tasks to do these negative factors can be offset with daily physical education. We measured children participating in physical education on a daily basis, consisting of 5th (10-11 years old) and 9th (14-15 years old) grade students and control groups of 4th (9-10 years old) and 8th (13-14 years old) grade students, respectively, for a total of 196 persons (94 girls and 102 boys). Habitual physical activity was obtained with Actigraph, (GT1M/GT3X) and body fat percentage was calculated from anthropometrical measurements. As expected, we were able to observe a linear correlation between the physical activity levels and the body composition of the participants. The more time the subjects spent performing MVPA (Moderate and Vigorous Physical Activity), the less body fat they had. The recommended MVPA is a minimum of one hour per day, but these Hungarian children had two hours of MPVA per day. Our results lead us to conclude that ninety minutes of additional physical education per week for 7-8 months cannot be considered sufficient for a full impact analysis nor for schoolchildren’s physical activity needs or body composition, though an increase in the amount of time spent in physical education classes shows beneficial effects for these children

Modulation of Ventral Prefrontal Cortex Functional Connections Reflects the Interplay of Cognitive Processes and Stimulus Characteristics

Emerging ideas of brain function emphasize the context-dependency of regional contributions to cognitive operations, where the function of a particular region is constrained by its pattern of functional connectivity. We used functional magnetic resonance imaging to examine how modality of input (auditory or visual) affects prefrontal cortex (PFC) functional connectivity for simple working memory tasks. The hypothesis was that PFC would show contextually dependent changes in functional connectivity in relation to the modality of input despite similar cognitive demands. Participants were presented with auditory or visual bandpass-filtered noise stimuli, and performed 2 simple short-term memory tasks. Brain activation patterns independently mapped onto modality and task demands. Analysis of right ventral PFC functional connectivity, however, suggested these activity patterns interact. One functional connectivity pattern showed task differences independent of stimulus modality and involved ventromedial and dorsolateral prefrontal and occipitoparietal cortices. A second pattern showed task differences that varied with modality, engaging superior temporal and occipital association regions. Importantly, these association regions showed nonzero functional connectivity in all conditions, rather than showing a zero connectivity in one modality and nonzero in the other. These results underscore the interactive nature of brain processing, where modality-specific and process-specific networks interact for normal cognitive operations