Self-Reported Academic Performance and Lifestyle Habits of School Children in Japan

Background and Objective: The purpose of this study was to determine the lifestyle habits significantly associated with self-reported academic performance (AP) in children in grades 5 to 12 in Japan. Methods: A total of 2,114 completed questionnaires were analyzed. Factors examined included habits related to sleeping, eating, defecation, physical activity, and screen time, in addition to body mass index (BMI). Social jet lag (SJL) was calculated from sleeping factors and categorized into five groups according to its value: minus 1 or less (SJL 1), more than minus 1 and 0 or less (SJL 2), more than 0 and 1 or less (SJL 3), more than 1 and 2 or less (SJL 4), and more than 2 (SJL 5). The association between self-reported AP and other factors except for SJL was assessed by means of multinomial logistic regression analysis. Results: Factors significantly associated with good self-reported AP included female gender, lower grade, less sleepiness, lower BMI, intake of breakfast, less constipation, early wake-up time during the weekend, and short screen time during the weekend. The mean self-reported AP of SJL 3 was better than that of both SJL 5 and SJL 1. Conclusions: Self-reported AP was associated with gender, grade, BMI, sleep, breakfast, defecation, and screen time in children in grades 5 to 12 in Japan. It must be ensured that children take enough time to perform the indispensable human behaviors of sleeping, eating, defecation, and physical activity

Shorter sleep duration and better sleep quality are associated with greater tissue density in the brain

Poor sleep quality is associated with unfavorable psychological measurements, whereas sleep duration has complex relationships with such measurements. The aim of this study was to identify the associations between microstructural properties of the brain and sleep duration/sleep quality in a young adult. The associations between mean diffusivity (MD), a measure of diffusion tensor imaging (DTI), and sleep duration/sleep quality were investigated in a study cohort of 1201 normal young adults. Positive correlations between sleep duration and MD of widespread areas of the brain, including the prefrontal cortex (PFC) and the dopaminergic systems, were identified. Negative correlations between sleep quality and MD of the widespread areas of the brain, including the PFC and the right hippocampus, were also detected. Lower MD has been previously associated with more neural tissues in the brain. Further, shorter sleep duration was associated with greater persistence and executive functioning (lower Stroop interference), whereas good sleep quality was associated with states and traits relevant to positive affects. These results suggest that bad sleep quality and longer sleep duration were associated with aberrant neurocognitive measurements in the brain in healthy young adults

Sleep habits, academic performance, and the adolescent brain structure

Here we report the first and most robust evidence about how sleep habits are associated with regional brain grey matter volumes and school grade average in early adolescence. Shorter time in bed during weekdays, and later weekend sleeping hours correlate with smaller brain grey matter volumes in frontal, anterior cingulate, and precuneus cortex regions. Poor school grade average associates with later weekend bedtime and smaller grey matter volumes in medial brain regions. The medial prefrontal anterior cingulate cortex appears most tightly related to the adolescents' variations in sleep habits, as its volume correlates inversely with both weekend bedtime and wake up time, and also with poor school performance. These findings suggest that sleep habits, notably during the weekends, have an alarming link with both the structure of the adolescent brain and school performance, and thus highlight the need for informed interventions.Peer reviewe

Untargeted metabolomics analysis of rat hippocampus subjected to sleep fragmentation

Sleep fragmentation (SF) commonly occurs in several pathologic conditions and is especially associated with impairments of hippocampus-dependent neurocognitive functions. Although the effects of SF on hippocampus in terms of protein or gene levels were examined in several studies, the impact of SF at the metabolite level has not been investigated. Thus, in this study, the differentially expressed large-scale metabolite profiles of hippocampus in a rat model of SF were investigated using untargeted metabolomics approaches. Forty-eight rats were divided into the following 4 groups: 4-day SF group, 4-day exercise control (EC) group, 15-day SF group, and 15-day EC group (n = 12, each). SF was accomplished by forced exercise using a walking wheel system with 30-s on/90-s off cycles, and EC condition was set at 10-min on/30-min off. The metabolite profiles of rat hippocampi in the SF and EC groups were analyzed using liquid chromatography/mass spectrometry. Multivariate analysis revealed distinctive metabolic profiles and marker signals between the SF and corresponding EC groups. Metabolic changes were significant only in the 15-day SF group. In the 15-day SF group, L-tryptophan, myristoylcarnitine, and palmitoylcarnitine were significantly increased, while adenosine monophosphate, hypoxanthine, L-glutamate, L-aspartate, L-methionine, and glycerophosphocholine were decreased compared to the EC group. The alanine, aspartate, and glutamate metabolism pathway was observed as the common key pathway in the 15-day SF groups. The results from this untargeted metabolomics study provide a perspective on metabolic impact of SF on the hippocampus.Peer reviewe

Preschool sleep and depression interact to predict gray matter volume trajectories across late childhood to adolescence

There is a close relationship between sleep and depression, and certain maladaptive outcomes of sleep problems may only be apparent in individuals with heightened levels of depression. In a sample enriched for preschool depression, we examined how sleep and depression in early childhood interact to predict later trajectories of gray matter volume. Participants (N = 161) were recruited and assessed during preschool (ages 3-6 years) and were later assessed with five waves of structural brain imaging, spanning from late childhood to adolescence. Sleep and depression were assessed using a semi-structured parent interview when the children were preschool-aged, and total gray matter volume was calculated at each scan wave. Although sleep disturbances alone did not predict gray matter volume/trajectories, preschool sleep and depression symptoms interacted to predict later total gray matter volume and the trajectory of decline in total gray matter volume. Sleep disturbances in the form of longer sleep onset latencies, increased irregularity in the child\u27s sleep schedule, and higher levels of daytime sleepiness in early childhood were all found to interact with early childhood depression severity to predict later trajectories of cortical gray matter volume. Findings provide evidence of the interactive effects of preschool sleep and depression symptoms on later neurodevelopment

Self-reported sleep relates to hippocampal atrophy across the adult lifespan: results from the Lifebrain consortium.

OBJECTIVES: Poor sleep is associated with multiple age-related neurodegenerative and neuropsychiatric conditions. The hippocampus plays a special role in sleep and sleep-dependent cognition, and accelerated hippocampal atrophy is typically seen with higher age. Hence, it is critical to establish how the relationship between sleep and hippocampal volume loss unfolds across the adult lifespan. METHODS: Self-reported sleep measures and MRI-derived hippocampal volumes were obtained from 3105 cognitively normal participants (18-90 years) from major European brain studies in the Lifebrain consortium. Hippocampal volume change was estimated from 5116 MRIs from 1299 participants for whom longitudinal MRIs were available, followed up to 11 years with a mean interval of 3.3 years. Cross-sectional analyses were repeated in a sample of 21,390 participants from the UK Biobank. RESULTS: No cross-sectional sleep-hippocampal volume relationships were found. However, worse sleep quality, efficiency, problems, and daytime tiredness were related to greater hippocampal volume loss over time, with high scorers showing 0.22% greater annual loss than low scorers. The relationship between sleep and hippocampal atrophy did not vary across age. Simulations showed that the observed longitudinal effects were too small to be detected as age-interactions in the cross-sectional analyses. CONCLUSIONS: Worse self-reported sleep is associated with higher rates of hippocampal volume decline across the adult lifespan. This suggests that sleep is relevant to understand individual differences in hippocampal atrophy, but limited effect sizes call for cautious interpretation

Resiliency as a mediator of the impact of sleep on child and adolescent behavior

First published online 23 December 2013Background: Disturbed sleep is detrimental to child behavior; however, the precise means by which this association occurs is unclear. Sleep and resilience can theoretically share an underlying neural mechanism and therefore influence one another. However, the role of resilience in the association between sleep and behavior is not known. The associations between sleep, resilience, and problematic behavior in children and adolescents aged 7–18 years were investigated in this study. Methods: A correlational design was used to determine the relationships between total sleep problems, indices of resilience, and internalizing and externalizing behaviors. Results: Sleep problems and resiliency variables were strongly correlated, and further, sleep problems were found to be predictive of resiliency scores. Resiliency significantly mediated the relationship between increased sleep problems and both overall internalizing and externalizing behavior problems, and specifically, measures of depression and anxiety. Conclusion: Sleep impacted levels of resilience such that greater sleep disturbance reduced resilience and consequently increased problematic behavior, potentially predisposing individuals to psychopathology.Alex Chatburn, Scott Coussens, Mark J Kohle

Sesta, atividade motora e desempenho cognitivo de crianças da educação infantil

Orientador : Prof. Dr. Fernando Mazzilli LouzadaDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Fisiologia. Defesa: Curitiba, 30/07/2012Bibliografia: fls. 46-49Àrea de concentração: NeurobiologiaResumoResumo: O sono é de vital importância para o desenvolvimento infantil. Crianças que vão à escola pela manhã dificilmente obtêm a quantidade recomendada de sono. Para reduzir a privação de sono, associada a problemas cognitivos e comportamentais, centros de educação infantil os quais atendem em período integral costumam possibilitar que as crianças durmam a sesta. Neste estudo, analisamos a influência da sesta sobre a atividade motora e o desempenho cognitivo de cinqüenta préescolares de dois centros municipais de educação infantil (CMEIs) da cidade de Curitiba-PR: Um em que as crianças podiam optar por permanecer acordadas (CMEI I) e outro no qual eram estimuladas a dormir a sesta todos os dias (CMEI II). As crianças usaram actímetros por sete dias e sete noites e realizaram tarefas cognitivas em um dia no qual haviam dormido a sesta e em outro no qual não o haviam feito. Por meio de ANOVAs de medidas repetidas, foi verificada a influência dos fatores CMEI e sesta sobre a atividade motora média registrada pelos actímetros entre as 14:00 e as 16:00 horas e sobre o desempenho nas tarefas cognitivas. Foi detectada influência do fator CMEI e da interação CMEI - sesta sobre a atividade motora das crianças. Enquanto no CMEI I a atividade motora manteve-se estável nas duas condições, no CMEI II a atividade motora foi maior na condição sem sesta. O desempenho nas tarefas cognitivas não diferiu entre as duas condições para nenhum dos dois CMEIs. Nossos dados sugerem que a privação da sesta resulta em atividade motora aumentada apenas para crianças desacostumadas a esta condição e que não traz prejuízos imediatos à cognição de pré-escolaresAbstract: Sleep is vital for children's development. Children who go to school in the morning seldom get the recommended sleep amount. In order to reduce sleep deprivation, associated to cognitive and behavioral problems, child care centers (CCC) which children attend full-time usually allow some time for napping. Here, we analyzed the influence of napping on the motor activity and the cognitive performance of fifty preschool from two CCCs in the city of Curitiba-PR, Brazil: One where the children had the choice to nap or stay awake (CCC I) and another one where they were all encouraged to nap (CCC II). The children wore actigraphs for seven days and seven nights and performed cognitive tasks on one day in which they had napped and on another one in which they had not. The influence of the CCC and nap factors on the mean motor activity registered by the actigraphs from 14:00 to 16:00 o' clock and the performance on the cognitive tasks were checked through repeated measure ANOVAs. It was detected the influence of the CCC factor and of the interaction CCCnap on the children's motor activity. While in the CCC I the motor activity remained stable in the nap and non-nap conditions, in the CCC II the motor activity was higher in the non-nap condition. The performance in the cognitive tasks did not differ between the two conditions for either of the CCCs. Our data suggest that the deprivation of napping results in increased motor activity only for children who are not accustomed to this condition and it is not associated to an immediate decrement of preschool children's cognitive performance

Consolidation of vocabulary during sleep : the rich get richer?

Sleep plays a role in strengthening new words and integrating them with existing vocabulary knowledge, consistent with neural models of learning in which sleep supports hippocampal transfer to neocortical memory. Such models are based on adult research, yet neural maturation may mean that the mechanisms supporting word learning vary across development. Here, we propose a model in which children may capitalise on larger amounts of slow-wave sleep to support a greater demand on learning and neural reorganisation, whereas adults may benefit from a richer knowledge base to support consolidation. Such an argument is reinforced by the well-reported “Matthew effect”, whereby rich vocabulary knowledge is associated with better acquisition of new vocabulary. We present a meta-analysis that supports this association between children’s existing vocabulary knowledge and their integration of new words overnight. Whilst multiple mechanisms likely contribute to vocabulary consolidation and neural reorganisation across the lifespan, we propose that contributions of existing knowledge should be rigorously examined in developmental studies. Such research has potential to greatly enhance neural models of learning