Function In School-aged Children Research Articles

Executive functions as mediators between socioeconomic status and academic performance in Chinese school-aged children

BackgroundIt is well-documented that socioeconomic status (SES) and academic performance in school-aged children are closely related. However, little is known about how the three core executive functions (EFs), inhibition, working memory, and cognitive flexibility, mediate the association between the two. Moreover, most previous studies examined SES disparities in Western countries, how such disparities in EF and academic performance manifest in the Chinese context, where a distinctive EF profile and learning experience are observed, remains uncertain. The current study explored: (1) the mediating effects of the three core EFs in the association between SES and academic performance; and (2) the differences in EF and academic performance in three core subjects between Chinese children who are below and above the poverty line. MethodsOf the 385 students sampled, 205 are in the low-SES group and 180 are in the middle-high SES group. ResultsA structural equation model showed that the SES-academic performance relationship was fully mediated by cognitive flexibility and working memory but not inhibition. Working memory was a much stronger mediator than cognitive flexibility, suggesting that working memory may correlate with childhood SES and academic performance in Chinese children. An analysis of covariance suggested that compared to the middle-high SES group, the low-SES group demonstrated poorer working memory and academic performance in all three subjects after controlling for age and IQ. Interestingly, children with low-SES were found to have better cognitive flexibility than children with middle-high SES. ConclusionsThese findings suggest that interventions targeting working memory may be an important area to improve children's academic performance.

Prenatal and postnatal exposure to ambient air pollution and cognitive function in school-age children in France

Prenatal and postnatal exposure to ambient air pollution and cognitive function in school-age children in France

Interaction of fluoride exposure and CREB1 gene polymorphisms on thyroid function in school-age children

To evaluate the effects of CREB1 gene polymorphisms and long-term exposure to fluoride on thyroid function of children. A total of 424 children (including 226 boys and 198 girls) aged 7-12 years old were enrolled in Kaifeng, China by cross-sectional study in 2017. The concentrations of urinary fluoride (UF) and creatinine (UCr) were measured using fluoride ion-selective electrode assay and creatinine assay kit (picric acid method), respectively. The concentration of UCr-adjusted UF (CUF) was calculated. Children were divided into high fluoride exposure group (HFG, CUF >1.41mg/L) and low fluoride exposure group (LFG, CUF ≤1.41mg/L) according to the median concentration of CUF (1.41mg/L). The serum thyroid-stimulating hormone (TSH), total triiodothyronine (TT3) and total thyronine (TT4) levels were detected by the radiation immunoassay. The B-mode ultrasound was performed to test the thyroid volume (Tvol). Genotyping of CREB1 gene was conducted by a custom-by-design 48-plex SNPscan™ Kit. Associations between CUF concentration, CREB1 single nucleotide polymorphisms (SNPs) and thyroid function were assessed by multiple linear regression models. Negative and positive associations between serum TT4 level (β=-0.721, 95%CI: -1.209, -0.234) and Tvol (β=0.031, 95%CI: 0.011, 0.050) and CUF concentration were observed respectively. Children carrying CREB1 rs11904814 TG and rs2254137 AC genotypes had lower TT3 levels (P<0.05). Children in HFG carrying rs11904814 TT, rs2253206 GG genotypes and rs6740584 C allele easily manifested lower serum TT4 levels (P<0.05). Moreover, interactions between excessive fluoride exposure and CREB1 SNPs on Tvol were observed, and the interaction among different loci of CREB1 gene could modify serum TT3 level (P<0.05, respectively). Fluoride could alter children's serum TT4 levels and Tvol. Interactions between fluoride exposure and CREB1 polymorphisms may modify thyroid volume of children.

Association between dietary quality and executive functions in school-aged children with autism spectrum disorder.

BackgroundIt is well known that children with autism spectrum disorder (ASD) had executive functions deficit. However, it is still unclear whether the poor dietary quality is related to the impairment of executive functions. The current study aimed to explore the association between dietary quality and executive functions in children with ASD.MethodsA total of 106 children with ASD (7.7 ± 1.3 years) and 207 typically developing (TD) children (7.8 ± 1.3 years) were enrolled from Guangzhou, China. The Chinese version of Behavior Rating Scale of Executive function (BRIEF), the working memory subscales of the Chinese version of Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV), and the Stroop Color-Word Test (SCWT) were used to measure the participant's executive functions. The food frequency questionnaire (FFQ) was used to collect the dietary intake information, and the Chinese Diet Balance Index (DBI_16) was used to evaluate the dietary quality. Generalized linear models were used to estimate the association between dietary quality and executive functions.ResultsIn children with ASD, Low Bound Score (LBS) was positively correlated with the working memory subscale score of BRIEF (β = 0.23, 95% CI: 0.02–0.44, P < 0.05), while High Bound Score (HBS) and LBS were positively correlated with the organizable subscale score of BRIEF (β = 0.44, 95% CI: 0.11–0.77, P < 0.01; β = 0.19, 95% CI: 0.01–0.37, P < 0.05). Compared to TD children, children with ASD had a higher proportion of moderate and high levels of insufficient dietary intake (moderate level, 37.7% vs. 23.2%, high level, 4.7% vs. 1.4%) and moderate level of unbalanced dietary intake (36.8% vs.21.3%), higher scores on all subscales of BRIEF (P < 0.01), and lower score on the working memory (81.3 ± 32.3 vs. 104.6 ± 12.5, P < 0.01), while there was no difference on the SCWT.ConclusionPoor dietary quality was associated with the impairment of working memory and organizational capacity in children with ASD. This study emphasized the importance of dietary quality in executive functions among children with ASD, and attention should be paid to improving their dietary quality.

Academic performance in school-age children: Association with sleep duration, but not study time

Academic performance in school-age children: Association with sleep duration, but not study time

The Theory of Mind Performance in School-Age children with Down syndrome and autism spectrum disorder

Theory of Mind (ToM) is ability in children and adolescents plays a key role to achieve the cognitive development, emotional and social cognition, which can enhance their communication ability. The study reported herein explored the comprehension of the ToM in Down syndrome (DS), Autism Spectrum Disorders (ASD), and typically development children (TD) during middle childhood and examined the role of IQ in the Theory of Mind. The participants were 74 Iranian school-aged between 6 and 12 years who participated in three groups: 24 ASD, 24 DS, and 26 TD. Children were compared to ToM tasks and first-, second-and third-order ToM tasks. Participants’ IQs were measured using the Raven’s Progressive Matrices (RPMs). We used SPSS 25 for analysis of variance (ANOVA), and correlation coefficient to assess the differences between the groups on ToM tasks. The level of significance was set at .05. These results show consistency with previous literature. TD group performed better than both clinical groups in all orders. ASD was competent to pass the first-order ToM tasks better than DS (p&lt; .001). These findings suggest that second-order did not show statistically significant in clinical groups. It also finds statistically significant between the TD group than both other groups (F= 55.13, p&lt; .001). For the third-order, children with DS did not perform statistically significant different (F= 4.99, p = 0.010) than children with ASD, and nor we found between ASD and TD groups. The IQ was significantly correlated with orders of false belief understanding. The significant consideration is required in further studies with more wide samples in other groups of neurodevelopment disorders.

Verbal and nonverbal memory in school-aged children born to opioid-dependent mothers

BackgroundThe potential long-term developmental effects of prenatal methadone and buprenorphine exposure during pregnancy are still largely unknown. AimsWe investigated memory function in school-aged children of women enrolled in opioid maintenance therapy (OMT) during pregnancy. Study designProspective longitudinal cohort study. SubjectsParticipants included 41 children (aged 9–11 years), 20 of which had histories of prenatal methadone or buprenorphine exposure. Outcome measuresVerbal and non-verbal memory function was assessed using four subtests from the Test of Memory and Learning - Second edition (TOMAL-2). ResultsThe OMT group scored lower on both the two non-verbal as well as the two verbal memory tasks, all p-values <.05. Group differences remained for three out of the four subtests after controlling for general IQ. Including maternal tobacco use during pregnancy increased the explanatory power of the model, R2 change of 0.07, p = .04. ConclusionsChildren prenatally exposed to methadone or buprenorphine had significantly lower memory performance, however, this association may in part be explained by maternal tobacco use during pregnancy. Consequently, smoking cessation programs should be systematically integrated into opioid maintenance therapy programs for pregnant women.

White matter microstructure associated with the range of attentional and impulsive performance in school-aged children

IntroductionInhibition capabilities have been shown to be a strong predictor of social and educational life outcomes (Mischel &amp; Ebbesen, 1970; Shoda et al., 1990). Inhibition capabilities have an enormous impact on attention and impulsivity (Bari &amp; Robbins, 2013). These two executive functions are associated with numerous psychiatric disorders but are not well understood in terms of white matter (WM) connectivity (Puiu et al., 2018). Novel techniques and statistical approaches in neuroimaging bring us closer to a biologically sustained model.ObjectivesThis research aims to: 1) identify WM connections associated with attention/impulsivity performance and 2) characterize the differences in WM microstructure associated with the variation of the performance.Methods 157 children (GESTE cohort, 8-12 years, 27 Dx ADHD, 2 Dx ASD) with b=1500mm2/s, 2mm isotropic dMRI acquisitions were included. Tractography was performed with TractoFlow pipeline (Theaud et al., 2020). Dimensionality reduction of diffusion metrics yielded two components : microstructural complexity (DTI Metrics, AFD &amp; NuFo) and axonal density (AFD_fixel) (Chamberland et al., 2019). Attention/impulsivity were evaluated with the CPT3. Multivariate linear regression was performed in python.ResultsLower microstructural complexity was associated with poorer attentional performance on regions of the parietal lobe to the occipital gyrus (P-O, p=0.044, R2=0.14, Figure 1.) and the Broadman’s area 8 to area 6 (SF8-SF6, p=0.002, R2=0.12, Figure 1.). Lower axonal density was associated with a less impulsive pattern on SF8-SF6 (p=0.001, R2=0.13, Figure 1.). Results remained significant when removing children with an ADHD or ASD diagnosis.ConclusionsWe identified underlying difference in WM microstructure that may be associated with the variation in attention/impulsivity performance in school-aged children.DisclosureNo significant relationships.

Skin Carotenoids and Relations to Intellectual Abilities and Academic Achievement Among School-Aged Children

ObjectivesCarotenoids are pigments found abundantly in vegetables that accumulate in the human body (i.e., the skin and central nervous system) and can serve as biomarkers for higher diet quality. Skin carotenoids have been previously correlated with cognitive function in adults; however, the relation between skin carotenoids and cognition in children is unknown. This study aimed to assess the link between skin carotenoids and cognitive function in school-aged children. MethodsChildren ages 7–12 (N = 106) participated in a cross-sectional study. Skin carotenoids were measured using reflection spectroscopy. Intellectual abilities and academic achievement were measured using Woodcock-Johnson IV. Dietary carotenoid intake was assessed using the Block Food Frequency Questionnaire and body fat percentage was measured using dual energy x-ray absorptiometry. Following initial bivariate correlations, a partial spearman correlation was conducted assessing relationships between skin carotenoids and Woodcock-Johnson IV following adjustment of covariates. ResultsSkin carotenoids were inversely correlated to body fat percentage and positively associated with household income and dietary carotenoids. Additionally, bivariate correlations revealed that General Intellectual Ability and multiple subtests of achievement were positively related to skin carotenoid status. Following adjustment for body fat percentage, household income, and dietary carotenoids, only quantitate reasoning and broad math skills (applied problems, calculation, and math facts fluency) were positively related to skin carotenoids (rs = 0.24, P = 0.02; rs = 0.225, P = 0.027). ConclusionsSkin carotenoids were positively associated with quantitate reasoning, a form of fluid reasoning, and broad math skills in school-aged children. Although carotenoid status was positively associated with WCJ subsets, these relationships were partially accounted for by household income, child adiposity, and dietary intake. Skin carotenoids were positively related to several cognitive function measures in school-aged children. Funding SourcesThis study was funded by the Egg Nutrition Center.

Attributable risk factors for asymptomatic malaria and anaemia and their association with cognitive and psychomotor functions in schoolchildren of north-eastern Tanzania.

In Africa, children aged 5 to 15 years (school age) comprises more than 50% (>339 million) of the under 19 years population, and are highly burdened by malaria and anaemia that impair cognitive development. For the prospects of improving health in African citizens, understanding malaria and its relation to anaemia in school-aged children, it is crucial to inform targeted interventions for malaria control and accelerate elimination efforts as part of improved school health policy. We conducted a study to determine the risk factors for asymptomatic malaria and their association to anaemia. We explored the prevalence of antimalarial drug resistance as well as the association of asymptomatic malaria infection and anaemia on cognitive and psychomotor functions in school-aged children living in high endemic areas. This study was a comprehensive baseline survey, within the scope of a randomised, controlled trial on the effectiveness and safety of antimalarial drugs in preventing malaria and its related morbidity in schoolchildren. We enrolled 1,587 schoolchildren from 7 primary schools located in Muheza, north-eastern Tanzania. Finger-pricked blood samples were collected for estimation of malaria parasitaemia using a microscope, haemoglobin concentration using a haemoglobinometer, and markers of drug resistance processed from dried blood spots (DBS). Psychomotor and Cognitive functions were assessed using a ‘20 metre Shuttle run’ and a test of everyday attention for children (TEA-Ch), respectively. The prevalence of asymptomatic malaria parasitaemia, anaemia and stunting was 26.4%, 49.8%, and 21.0%, respectively with marked variation across schools. In multivariate models, asymptomatic malaria parasitaemia attributed to 61% of anaemia with a respective population attribution fraction of 16%. Stunting, not sleeping under a bednet and illiterate parent or guardian were other factors attributing to 7%, 9%, and 5% of anaemia in the study population, respectively. Factors such as age group (10–15 years), not sleeping under a bednet, low socioeconomic status, parents’ or guardians’ with a low level of education, children overcrowding in a household, and fewer rooms in a household were significantly attributed to higher malaria infection. There was no significant association between malaria infection or anaemia and performance on tests of cognitive function (sustained attention) or psychomotor function (VO2 max). However, a history of malaria in the past one month was significantly associated with decreased cognitive scores (aOR = -4.1, 95% CI -7.7–0.6, p = 0.02). Furthermore, stunted children had significantly lower VO2max scores (aOR = -1.9, 95% CI -3.0–0.8, p = 0.001). Regarding the antimalarial drug resistance markers, the most prevalent Pfmdr1 86-184-1034-1042-1246 haplotypes were the NFSND in 47% (n = 88) and the NYSND in 52% (n = 98). The wild type Pfcrt haplotypes (codons 72–76, CVMNK) were found in 99.1% (n = 219) of the samples. Malaria, stunting and parents’ or guardians’ illiteracy were the key attributable factors for anaemia in schoolchildren. Given malaria infection in schoolchildren is mostly asymptomatic; an addition of interventional programmes such as intermittent preventive treatment of malaria in schoolchildren (IPTsc) would probably act as a potential solution while calling for an improvement in the current tools such as bednet use, school food programme, and community-based (customised) health education with an emphasis on nutrition and malaria control.

The developmental impact of sex chromosome trisomies on emerging executive functions in young children: Evidence from neurocognitive tests and daily life skills.

Sex chromosomal trisomies (SCT) are associated with impairments in executive functions in school-aged children, adolescents, and adults. However, knowledge on preschool development of executive functions is limited but greatly needed to guide early intervention. The current study examined emerging executive functions in young children with SCT. Participants were 72 SCT children and 70 population-based controls, aged 3-7 years, who completed a neurocognitive assessment of both global executive function (MEFS) and verbal executive function skills (NEPSY Word Generation). Caregivers completed the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire to capture real-world behavioral manifestations of impairments in executive functions. Results showed that impairments were significantly more prevalent in SCT than in controls and already present from 3 years, specifically verbal executive functions and working memory. Broader more pronounced impairments were found in older children with SCT. Age was significantly related to executive functions, but specific domains showed different relations with age. For example, deficits in planning and organizing remained evident with older age in SCT whereas it declined with age in controls. Impairments in executive functions were present across different levels of intelligence. Already at an early age, impairments across executive functions should be considered part of the neurodevelopmental profile of SCT, which appear more prominent at later age. Future studies should investigate developmental pathways of executive functions in SCT, given its relevance in cognitive, social, and emotional development. Executive functions should be screened and monitored in children with SCT and could be an important target of preventive intervention.

EEG Global Coherence in Scholar ADHD Children during Visual Object Processing.

Among neurodevelopmental disorders, attention deficit hyperactivity disorder (ADHD) is the main cause of school failure in children. Notably, visuospatial dysfunction has also been emphasized as a leading cause of low cognitive performance in children with ADHD. Consequently, the present study aimed to identify ADHD-related changes in electroencephalography (EEG) characteristics, associated with visual object processing in school-aged children. We performed Multichannel EEG recordings in 16-year-old children undergoing Navon’s visual object processing paradigm. We mapped global coherence during the processing of local and global visual stimuli that were consistent, inconsistent, or neutral. We found that Children with ADHD showed significant differences in global weighted coherence during the processing of local and global inconsistent visual stimuli and longer response times in comparison to the control group. Delta and theta EEG bands highlighted important features for classification in both groups. Thus, we advocate EEG coherence and low-frequency EEG spectral power as prospective markers of visual processing deficit in ADHD. Our results have implications for the development of diagnostic interventions in ADHD and provide a deeper understanding of the factors leading to low performance in school-aged children.

Stand-Biased Desks Impact on Cognition in Elementary Students Using a Within-Classroom Crossover Design.

Background: There is emerging literature that standing desk interventions may help to improve cognitive performance in school-aged children. The current study examines how desks that promote standing affect cognition over the course of a school year in third, fourth, and sixth graders. Methods: Nighty-nine students between the ages of 8 and 12 (M = 10.23; 58% Male) were assigned to either stand-biased desks or traditional sitting desks. A within-classroom design was used with students switching desks after 9 weeks. Cognitive assessments and teacher behavioral ratings were administered at baseline and readministered before students switched desks and at the conclusion of the study. Results: There were no significant effects on cognition or behavioral ratings from standing-biased desk intervention. Grade significantly moderated the relationship between stand-biased desks and cognition in that third graders showed increased cognitive control (p = 0.02, f2 = 0.06). Further, sex moderated the relationship in that females at stand-biased desks showed increased cognitive control (p = 0.03, f2 = 0.04). Conclusions: These results suggest that stand-biased desks impact cognition depending on grade and sex, indicating a complex relationship that should be teased out further in future research. Stand-biased desks showed moderate improvements in cognition and no deleterious effects, suggesting that they may be a helpful classroom intervention for children in elementary school.

The effect of convergence insufficiency treatment on reading performance in school age children – A meta-analysis

Introduction/purpose: Convergence insufficiency (CI) is a binocular vision disorder characterised by difficulty maintaining convergence and fixation at near. Depending on the severity of the CI, patients can present with a variety of symptoms during near vision tasks. Some studies indicate an increased incidence of CI in children with reading difficulties. Although a lot of research has been done on the effects of CI-treatments on eye-related symptoms, not much is known about its effect on performance related symptoms such as reading difficulties. The purpose of this meta-analysis is to determine if CI-treatments have a positive effect on reading performance. Methods: A search string was created to gather all relevant clinical trials on the National Centre for Biotechnology Information (NCBI) and Cochrane libraries. Only clinical trials were included that provided pre- and post treatment data on the effect of CI-treatment on reading performance in school aged children (5-18y). A total of three relevant clinical trials were found that provided pre-and post-treatment data. Results: A total of 352 subjects in CI-treatment groups across three clinical trials and 104 subjects in a placebo group provided pre-and post CI-treatment data on the improvements of reading performance in school aged children. The cumulative within-group treatment effect size (0.21(SD 0.03) [95%CI: 0.15, 0.27]) and the cumulative within-group placebo effect size (0.22(SD 0.05) [95%CI: 0.13, 0.32]) for the improvement of reading performance after CI-treatment in school aged children with CI was calculated. Conclusion: CI-treatment has little to no true effect size on reading performance. Though CI-treatments will cause an increase in reading performance, this is likely caused by improvements in attention, motivation, or other psychological factors (placebo effect).

In utero exposure to bisphenols and asthma, wheeze, and lung function in school-age children: a prospective meta-analysis of 8 European birth cohorts.

In utero exposure to bisphenols, widely used in consumer products, may alter lung development and increase the risk of respiratory morbidity in the offspring. However, evidence is scarce and mostly focused on bisphenol A (BPA) only. To examine the associations of in utero exposure to BPA, bisphenol F (BPF), and bisphenol S (BPS) with asthma, wheeze, and lung function in school-age children, and whether these associations differ by sex. We included 3,007 mother-child pairs from eight European birth cohorts. Bisphenol concentrations were determined in maternal urine samples collected during pregnancy (1999-2010). Between 7 and 11years of age, current asthma and wheeze were assessed from questionnaires and lung function by spirometry. Wheezing patterns were constructed from questionnaires from early to mid-childhood. We performed adjusted random-effects meta-analysis on individual participant data. Exposure to BPA was prevalent with 90% of maternal samples containing concentrations above detection limits. BPF and BPS were found in 27% and 49% of samples. In utero exposure to BPA was associated with higher odds of current asthma (OR=1.13, 95% CI=1.01, 1.27) and wheeze (OR=1.14, 95% CI=1.01, 1.30) (p-interaction sex=0.01) among girls, but not with wheezing patterns nor lung function neither in overall nor among boys. We observed inconsistent associations of BPF and BPS with the respiratory outcomes assessed in overall and sex-stratified analyses. This study suggests that in utero BPA exposure may be associated with higher odds of asthma and wheeze among school-age girls.

The effect of EF on PM performance in school-age children

ABSTRACT Prospective memory (PM) is vital for children to live independently. Theoretical and empirical evidence has shown that executive function (EF) plays an important role in children’s PM. However, there is no EF training for the PM of school-age children. Therefore, a 4-week EF training programme was conducted in this study to investigate the transfer effects of training on event-based PM in 8- to 12-year-old children. Children were randomly assigned to the EF training or control groups. The results revealed that EF training was more effective in enhancing children’s PM performance; in particular, there was a transfer effect of EF. Further findings suggested that this transfer effect was observed only in older children, which supported the magnification account that those with strong EF abilities profit most. Moreover, the benefits of training were predicted by inhibition and switching ability. Altogether, EF training has the potential to improve children’s PM, especially for children with better EF.

The impact of psychopathology on academic performance in school-age children and adolescents

Psychiatric symptoms have consistently been associated with negative educational outcomes. However, possible confounding variables, such as comorbid mental and environmental conditions, have not been well addressed. This study examined whether mental health problems were significantly linked to academic performance in a Spanish school-based sample, after adjustment for co-occurring psychiatric symptoms and multiple contextual factors. Parents completed a questionnaire regarding child’s sociodemographic characteristics (i.e., gender, age, type of school, socioeconomic status, ethnicity), stressful events (i.e., adoption, parental divorce/separation, grade retention) and lifestyle (i.e., diet, sleep, screen time), along with the Child Behavior Checklist (CBCL). Academic performance was obtained from school records. The sample comprised 7036 students aged 5–17 with full data on the CBCL. Mixed-effects ordinal logistic regression analyses were conducted to investigate the association between psychopathology and academic achievement, controlling for potential confounders. When examined separately, higher scores on the CBCL scales were related to lower grades, regardless of sociodemographic factors. However, after controlling for the presence of other psychiatric symptoms, we found that students who reported more anxious/depressed and thought problems were less likely to perform poorly, while those with increased levels of attention problems and delinquent behavior had higher risk for academic underachievement. These associations remained mainly the same once stressful events and lifestyle were taken into account. This investigation demonstrates that anxious/depressed symptoms, thought problems, attention problems, and delinquent behavior are independently associated with academic performance, which emphasize the need for preventive and treatment interventions targeted at students’ mental health to improve their psychological well-being and functioning at school.

Effect of Warm-up on Fitness Performance of Schoolchildren. A Systematic Review

Abstract Introduction. The impact of different types of warm-up protocol on children’s performance is clearly an unresolved issue that has not yet been satisfactorily investigated. Consequently, the purpose of this review was to analyze the current literature on the subject. Material and Methods. The first step was to perform a search in PROSPERO with the keyword warm up. After that, five electronic bibliographic databases were searched through until April 10th, 2021: Web of Science (all databases), Scopus, SportDiscus, PubMed, and Google Scholar. Results. Six studies involving a total of 138 participants were included in the final analyses. Regarding the physical qualities that were assessed, 4 of the studies assessed strength through the vertical jump, 3 assessed running speed, one assessed anaerobic endurance (30 seconds) with a cycle ergometer and another assessed flexibility using the Sit &amp; Reach. Conclusions. The practice of dynamic or specific warm-up before training appears to improve speed and strength performance compared to no warm-up in school-age children. However, the effects of warm-up on endurance and flexibility performance in school-age children need to be further investigated.

Executive functions in school-aged children exposed to airborne manganese: A multilevel analysis

Neuropsychological alterations have been identified in populations heavily exposed to metals with neurotoxic potential, such as manganese (Mn). This study examined the associations between Mn environmental exposure in school-aged children and executive functions, using structural equation modeling. Children, aged between 7 and 12 years (N = 181), were recruited from four elementary schools located in a region that is under the influence of atmospheric emissions from a ferro-manganese alloy plant in the municipality of Simões Filho, Bahia, Brazil. The following cognitive functions were evaluated: Intelligence, Inhibitory Control, Cognitive Flexibility, Verbal and Design Fluency, Verbal and Visual Working Memory and Attention. We performed structural equation modeling to identify the following executive functions latent variables: working memory, inhibitory control and cognitive flexibility. We further analyzed the relations between executive functions and Mn measured in hair (MnH) and toenails (MnTn) with linear mixed models, after controlling for co-variables. A positive effect at the individual level on working memory, inhibition control and cognitive flexibility was observed with MnTn after controlling for co-variables, but no association was found with MnH levels. However, children attending school most environmentally exposed to Mn emissions, which had the highest rate of Mn dust deposition, had the poorest scores on working memory. These findings suggest both benefits and risk of Mn on children's cognitive development.

HABIT+tDCS: a study protocol of a randomised controlled trial (RCT) investigating the synergistic efficacy of hand-arm bimanual intensive therapy (HABIT) plus targeted non-invasive brain stimulation to improve upper extremity function in school-age children with unilateral cerebral palsy

IntroductionUnilateral spastic cerebral palsy (USCP) is characterised by movement deficits primarily on one body side. The best available upper extremity (UE) therapies are costly and intensive. Thus, there is an...