Assessment of Working Memory Capacity in Preschool Children Using the Missing Scan Task

The purpose of this study was to investigate the feasibility and validity of a modified version of Buschke's missing scan methodology, the Missing Scan Task (MST), to assess working memory capacity (WMC) and cognitive control processes in preschool children 3-6 years in age. Forty typically developing monolingual English-speaking children between 36 and 84 months in age participated in the study. The children were tested on measures of WMC (MST), verbal and nonverbal memory (NEPSY Narrative Memory and Memory for Designs subtests), and language skills (Peabody Picture Vocabulary Test, fourth edition). Children showed increased working memory capacity scores with age, as measured by the MST, with significant differences between 3- and 5-year-olds and 3- and 6-year-olds. Significant correlations were also found between the MST and language and verbal and nonverbal memory scores. MSTscores still remained significantly correlated with the other measures of memory even after age and global language were accounted for in a regression analysis, demonstrating that the MST captures unique variance related specifically to WMC and cognitive control processes used to retrieve and scan information in short-term memory (STM). The results of this study demonstrate that the MST is a feasible and valid methodology for assessing WMC in preschool children as young 3 years of age

Sleep Assessments In Healthy School-Aged Children Using Actigraphy: Concordance with Polysomnography

Actigraphic recordings (ACT) are widely used in school children as a less intrusive and more extended approach to evaluation of sleep problems. However, critical assessment of the validity and reliability of ACT against overnight polysomnography (NPSG) are unavailable. Thus, we explored the degree of concordance between NPSG and ACT in school-aged children to delineate potential ACT boundaries when interpreting pediatric sleep. Non-dominant wrist ACT was simultaneously recorded with NPSG in 149 healthy school-aged children (4.1 to 8.8 years old, 41.7% boys and 80.4% Caucasian) recruited from the community. Analyses were limited to the Actiware (MiniMitter-64) calculated parameters originating from 1-min epoch sampling and medium sensitivity threshold value of 40; i.e., Sleep Period Time (SPT), Total Sleep Time (TST) and Wake After Sleep Onset (WASO). SPT was not significantly different between ACT and NPSG. However, ACT significantly underestimated TST by 32.2±33.4 minutes, and overestimated WASO by 26.3±34.4 minutes. The decreased precision of ACT was also evident from moderate to small concordance correlation coefficients (0.47 for TST and 0.09 for WASO). ACT in school-aged children provides reliable assessment of sleep quantity, but is relatively inaccurate during determination of sleep quality. Thus, caution is advocated in drawing definitive conclusions from ACT during evaluation of the sleep disturbed child

Sleep Assessments In Healthy School-Aged Children Using Actigraphy: Concordance with Polysomnography

Actigraphic recordings (ACT) are widely used in school children as a less intrusive and more extended approach to evaluation of sleep problems. However, critical assessment of the validity and reliability of ACT against overnight polysomnography (NPSG) are unavailable. Thus, we explored the degree of concordance between NPSG and ACT in school-aged children to delineate potential ACT boundaries when interpreting pediatric sleep. Non-dominant wrist ACT was simultaneously recorded with NPSG in 149 healthy school-aged children (4.1 to 8.8 years old, 41.7% boys and 80.4% Caucasian) recruited from the community. Analyses were limited to the Actiware (MiniMitter-64) calculated parameters originating from 1-min epoch sampling and medium sensitivity threshold value of 40; i.e., Sleep Period Time (SPT), Total Sleep Time (TST) and Wake After Sleep Onset (WASO). SPT was not significantly different between ACT and NPSG. However, ACT significantly underestimated TST by 32.2±33.4 minutes, and overestimated WASO by 26.3±34.4 minutes. The decreased precision of ACT was also evident from moderate to small concordance correlation coefficients (0.47 for TST and 0.09 for WASO). ACT in school-aged children provides reliable assessment of sleep quantity, but is relatively inaccurate during determination of sleep quality. Thus, caution is advocated in drawing definitive conclusions from ACT during evaluation of the sleep disturbed child

Some Neurocognitive Correlates of Noise-Vocoded Speech Perception in Children With Normal Hearing: A Replication and Extension of )

OBJECTIVES: Noise-vocoded speech is a valuable research tool for testing experimental hypotheses about the effects of spectral degradation on speech recognition in adults with normal hearing (NH). However, very little research has utilized noise-vocoded speech with children with NH. Earlier studies with children with NH focused primarily on the amount of spectral information needed for speech recognition without assessing the contribution of neurocognitive processes to speech perception and spoken word recognition. In this study, we first replicated the seminal findings reported by ) who investigated effects of lexical density and word frequency on noise-vocoded speech perception in a small group of children with NH. We then extended the research to investigate relations between noise-vocoded speech recognition abilities and five neurocognitive measures: auditory attention (AA) and response set, talker discrimination, and verbal and nonverbal short-term working memory. DESIGN: Thirty-one children with NH between 5 and 13 years of age were assessed on their ability to perceive lexically controlled words in isolation and in sentences that were noise-vocoded to four spectral channels. Children were also administered vocabulary assessments (Peabody Picture Vocabulary test-4th Edition and Expressive Vocabulary test-2nd Edition) and measures of AA (NEPSY AA and response set and a talker discrimination task) and short-term memory (visual digit and symbol spans). RESULTS: Consistent with the findings reported in the original ) study, we found that children perceived noise-vocoded lexically easy words better than lexically hard words. Words in sentences were also recognized better than the same words presented in isolation. No significant correlations were observed between noise-vocoded speech recognition scores and the Peabody Picture Vocabulary test-4th Edition using language quotients to control for age effects. However, children who scored higher on the Expressive Vocabulary test-2nd Edition recognized lexically easy words better than lexically hard words in sentences. Older children perceived noise-vocoded speech better than younger children. Finally, we found that measures of AA and short-term memory capacity were significantly correlated with a child's ability to perceive noise-vocoded isolated words and sentences. CONCLUSIONS: First, we successfully replicated the major findings from the ) study. Because familiarity, phonological distinctiveness and lexical competition affect word recognition, these findings provide additional support for the proposal that several foundational elementary neurocognitive processes underlie the perception of spectrally degraded speech. Second, we found strong and significant correlations between performance on neurocognitive measures and children's ability to recognize words and sentences noise-vocoded to four spectral channels. These findings extend earlier research suggesting that perception of spectrally degraded speech reflects early peripheral auditory processes, as well as additional contributions of executive function, specifically, selective attention and short-term memory processes in spoken word recognition. The present findings suggest that AA and short-term memory support robust spoken word recognition in children with NH even under compromised and challenging listening conditions. These results are relevant to research carried out with listeners who have hearing loss, because they are routinely required to encode, process, and understand spectrally degraded acoustic signals

Verbal learning and memory in prelingually deaf children with cochlear implants

OBJECTIVE: Deaf children with cochlear implants (CIs) show poorer verbal working memory compared to normal-hearing (NH) peers, but little is known about their verbal learning and memory (VLM) processes involving multi-trial free recall. DESIGN: Children with CIs were compared to NH peers using the California Verbal Learning Test for Children (CVLT-C). STUDY SAMPLE: Participants were 21 deaf (before age 6 months) children (6-16 years old) implanted prior to age 3 years, and 21 age-IQ matched NH peers. RESULTS: Results revealed no differences between groups in number of words recalled. However, CI users showed a pattern of increasing use of serial clustering strategies across learning trials, whereas NH peers decreased their use of serial clustering strategies. In the CI sample (but not in the NH sample), verbal working memory test scores were related to resistance to the build-up of proactive interference, and sentence recognition was associated with performance on the first exposure to the word list and to the use of recency recall strategies. CONCLUSIONS: Children with CIs showed robust evidence of VLM comparable to NH peers. However, their VLM processing (especially recency and proactive interference) was related to speech perception outcomes and verbal WM in different ways from NH peers

A One-Hour Sleep Restriction Impacts Brain Processing in Young Children Across Tasks: Evidence From Event-related Potentials

The effect of mild sleep restriction on cognitive functioning in young children is unclear, yet sleep loss may impact children\u27s abilities to attend to tasks with high processing demands. In a preliminary investigation, six children (6.6 - 8.3 years of age) with normal sleep patterns performed three tasks: attention (“Oddball”), speech perception (conconant-vowel syllables) and executive function (Directional Stroop). Event-related potentials (ERP) responses were recorded before (Control) and following one-week of 1-hour per day of sleep restriction. Brain activity across all tasks following Sleep Restriction differed from activity during Control Sleep, indicating that minor sleep restriction impacts children\u27s neurocognitive functioning

EURRECA's General Framework to make the process of setting up micronutrient recommendations explicit and transparent

EURRECA is a Network of Excellence with the objective of addressing the problem of national variations in micronutrient recommendations and working towards a framework of advice to better inform policy-makers. It became apparent that the network needed a framework that puts the process of recommendation setting in the context of science, policy and society. Although variability in recommendations originates from the scientific evidence-base used and its interpretation (e.g. health outcomes, types and methods of evaluation of evidence, quantification of risk/benefit), the background information provided in the recommendation reports does not easily facilitate the disentangling of the relative contribution of these different aspects because of lack of transparency. The present report portrays the general framework (see Figure) that has been developed by and for EURRECA in order to make the process of setting up micronutrient recommendations explicit and transparent. In explaining the link from science to policy applications, the framework distinguishes four principal components or stages (see Figure). These stages are: a) Defining the nutrient requirements: A judgement about the (best) distribution(s) of the population requirement is necessary for estimating nutrient requirements. Many assumptions need to be made about the attributes of the population group. Furthermore, several factors (consumer behaviour as well as physiology) are to be included to characterize optimal health. b) Setting the nutrient recommendations: All available evidence is needed to formulate recommendations. Incorporating different endpoints provide the basis to formulate an optimal diet in terms of (non-)nutrients and food(group)s. c) Policy options: Policy options should be formulated on how the optimal diet can be achieved. They concern the advice of scientist and/or expert committees to the policy makers. Current policy options are setting up a task force, food based dietary guidelines, general health education, educational programme for specific group(s), voluntary or mandatory fortification, labelling, supplementation (general or for specific groups), inducing voluntary action in industry, legislation on micronutrient composition in food products, fiscal change, monitoring and evaluation of intake (via food consumption surveys) and/or nutritional status. d) Policy applications: Policies and planning, usually done by government, that lead to nutritional interventions or programmes. They usually require consideration of scientific, legal, regulatory, ethical and cultural issues, economic implications, and political and social priorities. This framework illustrates three dimensions of the process of setting (micro)nutrient requirements: 1) The logical sequence of scientific thinking from setting physiological requirements for nutritional health leading to evidence-based derivation of Nutrient Intake Values. 2) In the early stages nutritional and epidemiological science is the dominant source and in the later stages evidence from consumer and social sciences as well as stakeholder influences is used in deriving the options for changing the distribution of nutrient intakes. 3) The wider socio-political context: a feedback loop between health perception, actual health and food intake exists and is directly affected by the food industry and many other stakeholders. Moreover, from the viewpoint of policymakers, there are concerns for health promotion and disease prevention because of population health indices, costs of health care, and economic interests in the agro-food sector. In conclusion: A systematic approach for development and regular review of micronutrient requirements in Europe, transparently based on scientific evidence and best practices, enables national and international authorities/bodies to use the best available information obtained through evidence-based nutrition and accomplish well-considered food policy. Funded by an EU FP6 Network of Excellence (EURRECA, grant no. FP 6–036196-2). G. T. performed part of the work under a short-term contract for WHO Europe

Bicuspid and unicuspid aortic valves: Different phenotypes of the same disease? Insight from the GenTAC Registry

BackgroundUnicuspid aortic valve (UAV) is a rare disorder, often difficult to distinguish from bicuspid aortic valve (BAV). BAV and UAV share valve pathology such as the presence of a raphe, leaflet fusion, aortic stenosis, aortic regurgitation, and/or ascending aortic dilatation, but a comprehensive echocardiographic comparison of patients with UAV and BAV has not been previously performed.MethodsWe investigated UAV and BAV patients at an early stage of disease included in GenTAC, a national registry of genetically related aortic aneurysms and associated cardiac conditions. Clinical and echocardiographic data from the GenTAC Registry were compared between 17 patients with UAV and 17 matched‐controls with BAV.ResultsBaseline characteristics including demographics, clinical findings including family history of BAV and aortic aneurysm/coarctation, and echocardiographic variables were similar between BAV and UAV patients; aortic stenosis was more common and more severe in patients with UAV. This was evidenced by higher mean and peak gradient, smaller aortic valve area, and more advanced valvular degeneration (all P < .05). There were no significant differences in aortic dimensions, with a similar pattern of enlargement of the ascending aorta.ConclusionsThe similar baseline characteristics with more accelerated aortic valve degeneration and stenosis suggest that UAV represents an extreme in the spectrum of BAV syndromes. Therefore, it is reasonable to consider application of recommendations for the management of patients with BAV to those with the rarer UAV.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139976/1/chd12520.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139976/2/chd12520_am.pd

Physiological and public health basis for assessing micronutrient requirements in children and adolescents. The EURRECA network

This paper provides an overview of the current knowledge relating to the nutritional requirements and corresponding recommended nutrient intake values of children and adolescents for micronutrients and specificities related to these requirements in the course of childhood and adolescence in Europe. Aspects that can influence micronutrient requirements, such as physiological requirements and bioavailability of the nutrients in the organism, are discussed. The methodology used to obtain the data and also the main knowledge gaps regarding these concepts are emphasized. Methodological critical points in achieving the data and physiological aspects of children and adolescents are important in order to standardize the reference values for micronutrients among Europe for these stages of life