Longitudinal relationships between prospective memory, executive functions, and metacognition in young elementary school children

Prospective Memory (PM), executive functions (EF) and metacognition (MC) are relevant cognitive abilities for everyday functioning. They all seem to develop gradually in childhood and appear to be theoretically closely related; however, their empirical links remain unclear, especially in children. As a recent study revealed significant cross-sectional links between PM and EF, and a weaker but close link between PM and MC in 2nd graders (Spiess, Meier, & Roebers, submitted), this study focused on their short-term relationships and on their development. 119 children (MT1 =95 months, SDT1, = 4.8 months) completed the same tasks (one PM, three EF, one MC task) twice with a time-lag of 7 months. T-tests showed significant improvements in all tasks, except in the updating task. Different structural equation models were contrasted (AMOS); the best fitting model revealed that PMT2 was similarly predicted by PMT1 (r = .33) and EFT1 (r = .34). Additionally, EFT1 predicted MCT2 (r = .44), chi2(118, 119) = 128.91, p = .23, TLI = .968, CFI = .978, RMSEA = .028. Results show that PM, EF, and MC develop during childhood and also demonstrate that they are linked not only cross-sectionally, but longitudinally. Findings are discussed in a broader developmental framework.

Cortical thickness decreases with age in very preterm born school-children but not in term born controls

Background: Cortical gray matter thinning occurs during childhood due to pruning of inefficient synaptic connections and an increase in myelination. Preterms show alterations in brain structure, with prolonged maturation of the frontal lobes, smaller cortical volumes and reduced white matter volume. These findings give rise to the question if there is a differential influence of age on cortical thinning in preterms compared to controls. Aims: To investigate the relationship between age and cortical thickness in preterms when compared to controls. Study design and outcome measures: The automated surface reconstruction software FreeSurfer was applied to obtain measurements of cortical thickness based on T1-weighted MRI images. Subjects: Forty-one preterms (< 32 weeks gestational age and/or < 1500 gram birth weight) and 30 controls were included in the study (7-12 years). Results: Cortical thickness was lower in bilateral frontal and left parietal regions and higher in left temporal gyri in preterms compared to controls. However, these differences depended on age. In preterms, age correlated negatively with cortical thickness in right frontal, parietal and inferior temporal regions. Accordingly, cortical thickness was higher in young compared to old preterms in bilateral frontal, parietal and temporal regions. In controls, age was not associated with cortical thickness. Conclusion: In preterms, cortical thinning still seems to occur between the age of 7 and 12 years, mainly in frontal and parietal areas whereas in controls, a substantial part of cortical thinning appears to be completed before they reach the age of 7 years. These data indicate slower cortical thinning in preterms than in controls.

Oral Health Education Program on Dental Caries Incidence for School Children.

OBJECTIVE This 3-year retrospective controlled clinical trial assessed the effect of a school-based oral health education program on caries incidence in children. STUDY DESIGN A total of 240 students, aged 5 to 7 years, from two public schools in Monte Sião, Brazil, were included in this study. A school-based oral health education program was developed in one of the schools (experimental group), including 120 students, while the 120 students from the other school did not participate in the program (control group). All children were initially examined for dental caries (dmf-t), and after 3 years, 98 children from the experimental group and 96 from the control group were again examined and answered a questionnaire on oral health issues. The between-groups difference in caries incidence on permanent teeth was calculated using Poisson regression analyses. Logistic regression was used to observe the association between caries incidence and other variables. RESULTS More students from the experimental group stated knowing what was dental caries and declared that they use dental floss daily, but no significant differences in caries incidence was observed between the experimental and control groups. CONCLUSION The school-based oral health education program is not adequately efficient to decrease caries incidence after three years, but some issues about oral health knowledge could be slightly improved.

Cognitively engaging chronic physical activity, but not aerobic exercise, affects executive functions in primary school children: A group-randomized controlled trial

Although the positive effects of different kinds of physical activity (PA) on cognitive functioning have already been demonstrated in a variety of studies, the role of cognitive engagement in promoting children’s executive functions is still unclear. The aim of the present study was therefore to investigate the effects of two qualitatively different chronic PA interventions on executive functions in primary school children. 181 children aged between 10 and 12 years were assigned to either a 6-week physical education program with a high level of physical exertion and high cognitive engagement (team games), a physical education program with high physical exertion but low cognitive engagement (aerobic exercise), or to a physical education program with both low physical exertion and low cognitive engagement (control condition). Executive functions (updating, inhibition, shifting) and aerobic fitness (multistage 20-meter shuttle run test) were measured before and after the respective condition. Results revealed that both interventions (team games and aerobic exercise) have a positive impact on children’s aerobic fitness (4-5 % increase in estimated VO2max). Importantly, an improvement in shifting performance was found only in the team games and not in the aerobic exercise or control condition. Thus, the inclusion of cognitive engagement in PA seems to be the most promising type of chronic intervention to enhance executive functions in children, providing further evidence for the importance of the qualitative aspects of PA.

Molecular Characterization and Risk Factors of Giardia duodenalis among School Children from La Habana, Cuba

Giardia duodenalis is considered the most common protozoan infecting humans worldwide. Molecular characterization of G. duodenalis isolates has revealed the existence of eight groups (assemblages A to H) which differ in their host distribution. A cross-sectional study was conducted in 639 children from La Habana between January and December 2013. Two assemblage-specific PCRs were carried out for the molecular characterization. The overall prevalence of Giardia infection was 11.9%. DNA from 63 of 76 (82.9%) samples was successfully amplified by PCR-tpi, while 58 from 76 (76.3%) were detected by PCRE1-HF. Similar results by both PCRs were obtained in 54 from 76 samples (71%). According to these analyses, assemblage B and mixed assemblages A + B account for most of the Giardia infections in the cohort of children tested. Our current study identified assemblage B as predominant genotype in children infected with Giardia. Univariate analysis indicated that omission of washing hands before eating and keeping dogs at home were significant risk factors for a Giardia infection. In the future, novel molecular tools for a better discrimination of assemblages at the subassemblages level are needed to verify possible correlations between Giardia genotypes and symptomatology of giardiasis.

Characterization of diabetes risk factors of elementary school children in low income areas of San Antonio, Texas

The number of children developing type-2 diabetes mellitus (T2DM) is increasing globally, especially in Western countries. Previous studies have indicated that low socioeconomic status (SES) is a contributing factor to diabetes. This study of children examined the relationship of socioeconomic status and two physiological measures that are risk factors for diabetes: the level of fasting capillary glucose (FCG) and hyperglycemia, in which there is an elevated amount of glucose in the blood. This study utilized data from the study entitled Bienester: A School-Based Diabetes Mellitus Prevention Program. The sample was 1,426 fourth grade students from 27 San Antonio Independent School District elementary schools. The dependent variable was FCG and the independent variable was the median family income associated with the student's zip code based on Census information. Other variables included body mass index, gender, and ethnicity. The statistical results showed no relationship between FCG, continuously defined, and income. In addition, there was no relationship between hyperglycemia and income. Furthermore, there was no relationship of FCG with BMI, gender, or ethnicity. Income measured at the zip code level is likely too aggregate and distal an influence to demonstrate an impact on FCG. Research should continue to examine risk factors associated with the onset of T2DM.^

A path analysis of an after-school health and exercise program for elementary school children in El Paso, Texas

As schools are pressured to perform on academics and standardized examinations, schools are reluctant to dedicate increased time to physical activity. After-school exercise and health programs may provide an opportunity to engage in more physical activity without taking time away from coursework during the day. The current study is a secondary data analysis of data from a randomized trial of a 10-week after-school program (six schools, n = 903) that implemented an exercise component based on the CATCH physical activity component and health modules based on the culturally-tailored Bienestar health education program. Outcome variables included BMI and aerobic capacity, health knowledge and healthy food intentions as assessed through path analysis techniques. Both the baseline model (χ2 (df = 8) = 16.90, p = .031; RMSEA = .035 (90% CI of .010–.058), NNFI = 0.983 and the CFI = 0.995) and the model incorporating intervention participation proved to be a good fit to the data (χ2 (df = 10) = 11.59, p = .314. RMSEA = .013 (90% CI of .010–.039); NNFI = 0.996 and CFI = 0.999). Experimental group participation was not predictive of changes in health knowledge, intentions to eat healthy foods or changes in Body Mass Index, but it was associated with increased aerobic capacity, β = .067, p < .05. School characteristics including SES and Language proficiency proved to be significantly associated with changes in knowledge and physical indicators. Further effects of school level variables on intervention outcomes are recommended so that tailored interventions can be developed aimed at the specific characteristics of each participating school. ^

Formative evaluation of a parental involvement program for obesity prevention with low-income elementary school children

This study addresses the responses to a postcard campaign with health messages targeting the parents of children in a sample of low-income elementary schools and assesses the feasibility and areas of possible improvements in such a project. The campaign was implemented in Spring 2009 with 4 th grade students (n=1070) in fifteen economically disadvantaged elementary schools in Travis County, Texas. Postcards were sent home with children, and parents filled out a feedback card that the children returned to school. Response data, in the form of self-administered feedback cards (n=2665) and one-on-one teacher interviews (n=8), were qualitatively analyzed using NVivo 8 software. Postcard reception and points of improvement were then identified from the significant themes that emerged including health, cessation or reduction of unhealthy behaviors, motivation, family, and the comprehension of abstract health concepts. ^ Responses to the postcard campaign were almost completely positive, with less than 1% of responses reporting some sort of dislike, and many parents reported a modification of their behavior. However, possible improvements that could be made to the campaign are: increased focus of the postcards on the parents as the target population, increased information about serving size, greater emphasis on the link between obesity and health, alteration of certain skin tones used in the graphical depiction of people on the cards, and smaller but more frequent incentives to return the feedback cards for the students. The program appears to be an effective method of communicating health messages to the parents of 4th grade children.^

SEVERITY OF IRON DEFICIENCY ANEMIA AND ITS RELATIONSHIP TO GROWTH AND MORBIDITY IN A POPULATION OF PRE-SCHOOLERS IN RURAL GUATEMALA (IRON DEFICIENCY, MORBIDITY, GROWTH)

The objectives of this study were to determine the nature of the relationship between severity of iron deficiency anemia, response to iron treatment, respiratory and gastrointestinal illness and weight change. Seventy-five pre-school children from rural Guatemala received daily oral iron therapy for an eleven week period, and were classified into one of three groups having different degrees of iron deficiency anemia. Anthropometric and biochemical data were collected prior and after iron treatment; morbidity data were collected throughout the period of treatment. The outcome variables were percentage weight change, percentage of total days ill with any type of symptom, percentage of total days ill with gastrointestinal symptoms, percentage of total days ill with respiratory symptoms, percentage of total days ill with combination syndrome symptoms. Age, sex and socio-economic status, were independent of any of the independent or outcome variables used. On the other hand, the level of hemoglobin covaried with the height of the children, the smallest children were the most severely anemic. The relationships between hemoglobin levels and weight change, frequency of morbidity (gastrointestinal, respiratory and combination syndrome) and total number of days ill with any symptomatology were investigated. No statistical significance was found in these analyses except when contrasting children with normal hemoglobin levels to iron deficient children, where the findings indicated the normal children experienced more gastrointestinal morbidity. The same relationship were again analyzed but including delta hemoglobin as covariate in the analysis, this latter one was found to be significant at 7% when the percentage of days ill from gastrointestinal morbidity was tested against the hemoglobin groups. The relationship found indicates that, all other covariates accounted for, the percentage of days ill from gastrointestinal morbidity will decrease approximately 1% for each 1% increase in delta of hemoglobin. ^

THE EFFECT OF IRON SUPPLEMENT ON THE GROWTH OF RURAL INDONESIAN SCHOOL CHILDREN

The effect of oral iron supplementation on blood iron levels and physical growth in 119 Indonesian rural school children was assessed in the double-blind study. The children were classified into anemic and normal groups according to their initial hemoglobin and transferrin saturation levels and were randomly assigned to either iron or placebo treatment for twelve weeks. Biochemical, anthropometric and morbidity data were collected prior to and after the treatment period. Before treatment, anemic subjects were smaller and had higher morbidity than normal subjects. Treatment with 10 mg ferrous sulfate/kg/day for twelve weeks resulted in a significant improvement in blood iron biochemical status of the anemic subjects and in their growth velocity and morbidity. ^

The heart challenge: The effect of regular aerobic exercise on body fat distribution in third and fourth grade school children: A randomized clinical trial

The pattern of body fat distribution known as "centralized", and characterized by a predominance of subcutaneous fat on the trunk and a "pot belly", has been associated with an increased risk of chronic disease. These patterns of fat distribution, as well as the lifestyle habit variables associated with adult fatness and chronic morbidity clearly begin to develop during childhood, indicating the need for intervention and primary prevention of obesity, particularly the centralized form, during childhood or adolescence. The purpose of this study was to determine whether regular aerobic exercise could beneficially alter the distribution of body fat in 8 and 9 year old children. One hundred and eighty-eight participants were randomized into either a regular aerobic exercise treatment group or a standard physical education program control group. A variety of aerobic activities was used for intervention 5 days per week during physical education class for a period of 12 weeks. Fat distribution was measured by a number of the most commonly used indices, including ratios of body circumferences and skinfolds and indices derived from a principal components analysis. Change over time in average pulse rate was used to determine if intervention actually occurred. Approximately 10% of the students were remeasured, allowing the calculation of intra- and interexaminer measurement reliability estimates for all indices.^ This study group was comparable to the U.S. population, though the study children were slightly larger for certain measures. No effect of the exercise intervention was found. The most likely explanation for this was inadequacy of the intervention, as indicated by the lack of any change in average pulse rate with treatment. The results of the measurement reliability analysis are reported and indicate that body circumference ratios are more precise than skinfold ratios, particularly when multiple observers are used. Reliability estimates for the principal component indices were also high.^ It remains unclear whether the distribution of body fat can be altered with exercise. It is likely that this issue will remain undecided until one highly reliable, valid, and sensitive measure of fat distribution can be found. ^