Long-term consequences of early childhood malnutrition

"This paper examines the impact of preschool malnutrition on subsequent human capital formation in rural Zimbabwe using a maternal fixed effects-instrumental variables (MFE-IV) estimator with a long-term panel data set. Representations of civil war and drought 'shocks' are used to identify differences in preschool nutritional status across siblings. Improvements in height-for-age in preschoolers are associated with increased height as a young adult and number of grades of schooling completed. Had the median preschool child in this sample had the stature of a median child in a developed country, by adolescence, she would be 4.6 centimeters taller and would have completed an additional 0.7 grades of schooling." Authors' AbstractCivil war Africa ,

Metacognitive scaffolding boosts cognitive and neural benefits following executive attention training in children

Version of Record online: 25 October 2018Interventions including social scaffolding and metacognitive strategies have been used in educational settings to promote cognition. In addition, increasing evidence shows that computerized process-based training enhances cognitive skills. However, no prior studies have examined the effect of combining these two training strategies. The goal of this study was to test the combined effect of metacognitive scaffolding and computer-based training of executive attention in a sample of typically developing preschoolers at the cognitive and brain levels. Compared to children in the regular training protocol and an untrained active control group, children in the metacognitive group showed larger gains on intelligence and significant increases on an electrophysiological index associated with conflict processing. Moreover, changes in the conflict-related brain activity predicted gains in intelligence in the metacognitive scaffolding group. These results suggest that metacognitive scaffolding boosts the influence of process-based training on cognitive efficiency and brain plasticity related to executive attention.Secretaría de Estado de Investigación, Desarrollo e Innovación, Grant/Award Number: PSI2014-55833-

Towards Deciphering the Fetal Foundation of Normal Cognition and Cognitive Symptoms From Sulcation of the Cortex.

Growing evidence supports that prenatal processes play an important role for cognitive ability in normal and clinical conditions. In this context, several neuroimaging studies searched for features in postnatal life that could serve as a proxy for earlier developmental events. A very interesting candidate is the sulcal, or sulco-gyral, patterns, macroscopic features of the cortex anatomy related to the fold topology-e.g., continuous vs. interrupted/broken fold, present vs. absent fold-or their spatial organization. Indeed, as opposed to quantitative features of the cortical sheet (e.g., thickness, surface area or curvature) taking decades to reach the levels measured in adult, the qualitative sulcal patterns are mainly determined before birth and stable across the lifespan. The sulcal patterns therefore offer a window on the fetal constraints on specific brain areas on cognitive abilities and clinical symptoms that manifest later in life. After a global review of the cerebral cortex sulcation, its mechanisms, its ontogenesis along with methodological issues on how to measure the sulcal patterns, we present a selection of studies illustrating that analysis of the sulcal patterns can provide information on prenatal dispositions to cognition (with a focus on cognitive control and academic abilities) and cognitive symptoms (with a focus on schizophrenia and bipolar disorders). Finally, perspectives of sulcal studies are discussed

Executive Functions and Neurology in Children and Adolescents

This chapter discusses the theoretical and methodological issues of creating a developmental perspective on executive function (EF) in childhood and adolescence. Focusing on school periods, this section outlines the development of the basic components of EF—inhibition, working memory, and attention. Cognitive and neurophysiological evaluations show that despite the emergence of EF in the first few years of life, it continues to grow significantly in childhood and adolescence. The components vary slightly according to their developmental sequence. The chapter links findings to long-standing developmental issues (i.e. developmental sequences and processes) and suggests the necessary research to establish a developmental framework covering early childhood throughout adolescence

Doctor of Philosophy

dissertationIt has been acknowledged in the research on bilingualism that bilingual speakers, regardless of age, exhibit enhanced cognitive control capacity (e.g., interference control) as compared with their monolingual peers. Behavior and imaging studies suggest that these effects are the result of a shared neural network recruited by both linguistic processing and general-purpose cognitive control in bilinguals. The majority of studies on bilingual cognitive control examine two groups—an early bilingual group (individuals who have been exposed to two languages from a very early age) vs. a monolingual control group. Late bilinguals (i.e., people who acquire a second language later in life) are often excluded in studies of bilingual cognitive control. Yet it is precisely this population that makes up the majority of bilinguals in United States. This dissertation study compares an early bilingual group with two late bilingual groups in order to examine whether the cognitive processing advantage observed in bilinguals was associated with age of acquisition (AOA) or language proficiency. Data on cognitive control capacity were collected through three lab tasks that measured working memory capacity (WMC), response inhibition, and interference control, respectively. Results found that successful inhibition of prepotent responses was associated with higher WMC, later AOA, and higher language proficiency, while successful interference suppression was associated with higher WMC, earlier AOA, and higher language proficiency. An efficient speed-accuracy trade-off pattern was also observed in early bilinguals. Findings from this study are discussed under the framework of the adaptive control hypothesis

Relationships between musical and linguistic skills in early development: the role of informal musical experience in the home

Research on the relationship between formal musical training and cognitive abilities has been burgeoning over the last decade, with a specific focus on the relationship between language and music skills. However, a significant gap exists when looking at the start of the developmental path of the relationship between these abilities: whereas something is known about infants and a significant amount has been learned about school-aged children, very little is known about preschool children. Aiming to fill this gap, this research has moved along two interlocking paths: first, studying the early relationship between cognitive processing of both music and language, and second, evaluating a dimension so far unexplored: the influence of informal musical interaction and exposure in the home on musical and linguistic development. Using a correlational design and a set of novel age-appropriate musical abilities tasks, Study 1 examined the relationship between a range of musical skills and linguistic development in 3- and 4-year-old children. The second study investigated the contribution of informal musical experience in the home in the development of these skills. Based on the findings from Study 2, which suggested a significant association between informal musical experience in the home and the development of key language areas, Study 3 sought to develop a validated instrument with good psychometric properties for the assessment of informal musical experience. To this end, two online surveys were conducted, and factor analytical and confirmatory methods were used to explore and consolidate the factor structure of the new instrument (Music@Home Questionnaire). Reliability and validity of the new instrument were also investigated. Study 4 focused on a specific aspect of music and language processing namely, the processing of structure, and examined the hypothesis that these skills are related in 4- and 6-year-old children. Study 4 also investigated the impact of home experience with music, as assessed with the newly developed instrument, on language and music structural processing. The combined findings of the present thesis contribute towards a comprehensive account of the relationship between language and music from a developmental perspective. They also provide researchers with new tools to assess musical abilities in young children and with a novel parent-report instrument for the assessment of a largely unexplored area of environmental experience: i.e. informal musical experience in the home

Doctor of Philosophy

dissertationIt has been acknowledged in the research on bilingualism that bilingual speakers, regardless of age, exhibit enhanced cognitive control capacity (e.g., interference control) as compared with their monolingual peers. Behavior and imaging studies suggest that these effects are the result of a shared neural network recruited by both linguistic processing and general-purpose cognitive control in bilinguals. The majority of studies on bilingual cognitive control examine two groupsâ€"an early bilingual group (individuals who have been exposed to two languages from a very early age) vs. a monolingual control group. Late bilinguals (i.e., people who acquire a second language later in life) are often excluded in studies of bilingual cognitive control. Yet it is precisely this population that makes up the majority of bilinguals in United States. This dissertation study compares an early bilingual group with two late bilingual groups in order to examine whether the cognitive processing advantage observed in bilinguals was associated with age of acquisition (AOA) or language proficiency. Data on cognitive control capacity were collected through three lab tasks that measured working memory capacity (WMC), response inhibition, and interference control, respectively. Results found that successful inhibition of prepotent responses was associated with higher WMC, later AOA, and higher language proficiency, while successful interference suppression was associated with higher WMC, earlier AOA, and higher language proficiency. An efficient speed-accuracy trade-off pattern was also observed in early bilinguals. Findings from this study are discussed under the framework of the adaptive control hypothesis

The cognitive neuroscience of visual working memory

Visual working memory allows us to temporarily maintain and manipulate visual information in order to solve a task. The study of the brain mechanisms underlying this function began more than half a century ago, with Scoville and Milner’s (1957) seminal discoveries with amnesic patients. This timely collection of papers brings together diverse perspectives on the cognitive neuroscience of visual working memory from multiple fields that have traditionally been fairly disjointed: human neuroimaging, electrophysiological, behavioural and animal lesion studies, investigating both the developing and the adult brain

New risks and opportunities for food security: scenario analyses for 2015 and 2050

"Given the number of undernourished people in the developing world and the increasingly complex risks to food security, policymakers are faced with an enormous agenda. Freeing people from hunger will require more and better-targeted investments, innovations, and policy actions, driven by a keen understanding of the dynamic risks and forces that shape the factors affecting people's access to food and the links with nutrition. The International Food Policy Research Institute's (IFPRI's) International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) provides insight into the management of these risks through appropriate policy actions. By projecting future global food scenarios to 2050, IMPACT explores the potential implications of policy action and inaction in several main risk areas as well as the effects on child malnutrition in the developing world, commodity prices, demand, cereal yields, production, and net trade. In the progressive policy actions scenario, which assumes increased investment in rural development, health, education, and agricultural research and development, developing country governments and the international community are able to dramatically reduce the number of food-insecure people, leading to a worldwide decline in hunger. Under these conditions, Latin America and China are able to virtually eliminate child malnutrition by 2050. Bolstered by the development and dissemination of improved technologies and better infrastructure, crop production and yields increase in developing countries. Notably, the bulk of the growth in production is driven by yield increases rather than by expanding land area. Spurred by growth in the agricultural sector, average incomes in developing countries increase. Rising incomes bolster demand for high-value agricultural products, such as meat, dairy, and fruits and vegetables; global livestock production more than doubles, for example. Average per capita calorie supplies for developing countries exceed 3,400 per day, well in excess of minimum requirements. The policy failure scenario assumes greater political discord and more extensive agricultural protectionism, together with the failure of policies to deal with food emergencies related to conflict. Slow growth and trade restrictions lead to stagnation in average per capita calorie availability, which remains only slightly above minimum requirements until after 2030, when availability increases. In addition, crucial investments in agriculture, rural development, and poverty reduction are forgone or displaced. Because of limited investment in agricultural research and technology, this scenario has a high level of crop area expansion as a result of relatively rapid population growth and slim yield improvements in developing countries. This scenario also results in flat maize prices, declining per capita cereal demand, falling beef prices, and relatively flat meat demand. As a result of the policies in this scenario, the number of malnourished children in developing countries rises between 1997 and 2015, after which there are only modest declines. In the technology and natural resource management failure scenario, yield growth falls even more than under the preceding scenario, forcing farmers to move into marginal producing areas, which causes a more rapid expansion of cereal area into less productive land that does not compensate for the yield shortfalls (and causes environmental degradation). As a result, cereal prices rise substantially through 2030 and then fall off only gradually. Beef and other meat prices, which are affected by the price of feed, follow a similar pattern. Developing-country per capita calorie availability is essentially unchanged over 1997–2050 and remains at a barely adequate average level. Given unequal access to the food that is available, millions of people actually consume less than the minimum. The occurrence of child undernourishment is even higher than under the policy failure scenario in all developing-country regions. Overall, the technology and natural resource management failure scenario results in the worst impact on food security and child malnourishment in the developing world. The progressive policy scenario outlines several of the most crucial positive steps. National governments and the international community must assume a new focus on agricultural growth and rural development, along with increasing their investments in education, social services, and health. Policies to encourage synergistic growth in the nonfarm sectors are also needed to spur broad-based economic growth. Underpinning these strategies and research agendas must be a firm commitment to reducing hunger and improving the welfare of the world's undernourished people." From Authors' Executive SummaryImpact model, Caloric intake, Safety nets,

DEVELOPMENT OF NEURAL AND BEHAVIORAL INHIBITORY CONTROL DURING ADOLESCENCE: THE INTEGRATIVE EFFECTS OF FAMILY SOCIOECONOMIC STATUS AND PARENTING BEHAVIORS

Inhibitory control (IC) has drawn great attention from researchers and practitioners and the concurrent association between family socioeconomic status and IC in adolescence is well-documented. However, little is known about whether and how family socioeconomic status influence the individual differences in the development of adolescent IC. The current investigation aimed to address this gap in knowledge by employing two multiple-wave longitudinal studies of IC. In the early adolescent sample (N = 311), color-word Stroop task performance was assessed as a measure of IC when individuals were 10 and 13 years old. In the middle adolescent sample (N = 167), multisource interference task performance and corresponding neural activities were assessed as measures of IC, annually for four years from 14 to 17 years of age. Family socioeconomic status and three dimensions of parenting behaviors were measured through informant-rating surveys in both studies. In both samples, the longitudinal development of IC was examined first. Next, the direct and indirect effects of earlier vii family socioeconomic status on the development of IC via different parenting behaviors was studied. Also, the independent and interactive associations between family socioeconomic status and several parenting behaviors in the prediction of adolescent IC were examined. Results across these two studies revealed that IC continued to improve through adolescence. In the early adolescent sample study, family socioeconomic status showed significant indirect effects on behavioral IC via its influences on parenting behaviors--especially parental warmth and parental negativity. In the middle adolescent sample study, the interactive effects of family socioeconomic status and parenting behaviors were significant in predicting neural functioning related to IC. The association between family socioeconomic status and the intercept of neural correlates of IC was significant only among families with low parental warmth, high parental rejection and low parental monitoring. The current investigation extended the prior literature in systematically testing the longitudinal associations between family socioeconomic status, parenting behaviors and the development of behavioral and neural functioning of IC during adolescence. Implications of the current study for prevention and intervention were also discussed