Kimberly G. Noble

Family income, parental education and brain structure in children and adolescents

Socioeconomic disparities are associated with differences in cognitive development. The extent to which this translates to disparities in brain structure is unclear. We investigated relationships between socioeconomic factors and brain morphometry, independently of genetic ancestry, among a cohort of 1,099 typically developing individuals between 3 and 20 years of age. Income was logarithmically associated with brain surface area. Among children from lower income families, small differences in income were associated with relatively large differences in surface area, whereas, among children from higher income families, similar income increments were associated with smaller differences in surface area. These relationships were most prominent in regions supporting language, reading, executive functions and spatial skills; surface area mediated socioeconomic differences in certain neurocognitive abilities. These data imply that income relates most strongly to brain structure among the most disadvantaged children.

Neural correlates of socioeconomic status in the developing human brain

Socioeconomic disparities in childhood are associated with remarkable differences in cognitive and socio-emotional development during a time when dramatic changes are occurring in the brain. Yet, the neurobiological pathways through which socioeconomic status (SES) shapes development remain poorly understood. Behavioral evidence suggests that language, memory, social-emotional processing, and cognitive control exhibit relatively large differences across SES. Here we investigated whether volumetric differences could be observed across SES in several neural regions that support these skills. In a sample of 60 socioeconomically diverse children, highly significant SES differences in regional brain volume were observed in the hippocampus and the amygdala. In addition, SES × age interactions were observed in the left superior temporal gyrus and left inferior frontal gyrus, suggesting increasing SES differences with age in these regions. These results were not explained by differences in gender, race or IQ. Likely mechanisms include differences in the home linguistic environment and exposure to stress, which may serve as targets for intervention at a time of high neural plasticity.

Neuroscience Perspectives on Disparities in School Readiness and Cognitive Achievement

This article allows readers to look at racial and ethnic disparities in school readiness from a neuroscience perspective. Although researchers have traditionally measured gaps in school readiness using broad achievement tests, they can now assess readiness in terms of more specific brain-based cognitive functions. Three neurocognitive systems—cognitive control, learning and memory, and reading—are essential for success in school. Thanks to recent advances in brain imaging, it is now possible to examine these three systems, each located in specific areas of the brain, by observing them in action as children engage in particular tasks. Socioeconomic status—already linked with how well children do on skills tests generally—is particularly closely linked with how well they perform on tasks involving these crucial neurocognitive systems. Moreover, childrens life experiences can influence their neurocognitive development and lead to functional and anatomical changes in their brains. Noting that chronic stress or abuse in childhood can impair development of the brain region involved in learning and memory, the authors show how the extreme stress of being placed in an orphanage leads to abnormal brain development and decreased cognitive functioning. More optimistically, the authors explain that childrens brains remain plastic and capable of growth and development. Targeted educational interventions thus have the promise of improving both brain function and behavior. Several such interventions, for example, both raise childrens scores in tests of reading and increase activity in the brain regions most closely linked with reading. The brain regions most crucial for school readiness may prove quite responsive to effective therapeutic interventions—even making it possible to tailor particular interventions for individual children. The authors look ahead to the day when effective educational interventions can begin to close racial and socioeconomic gaps in readiness and achievement.

Socioeconomic status and structural brain development

Recent advances in neuroimaging methods have made accessible new ways of disentangling the complex interplay between genetic and environmental factors that influence structural brain development. In recent years, research investigating associations between socioeconomic status (SES) and brain development have found significant links between SES and changes in brain structure, especially in areas related to memory, executive control, and emotion. This review focuses on studies examining links between structural brain development and SES disparities of the magnitude typically found in developing countries. We highlight how highly correlated measures of SES are differentially related to structural changes within the brain.

State of the art review: poverty and the developing brain

In the United States, >40% of children are either poor or near-poor. As a group, children in poverty are more likely to experience worse health and more developmental delay, lower achievement, and more behavioral and emotional problems than their more advantaged peers; however, there is broad variability in outcomes among children exposed to similar conditions. Building on a robust literature from animal models showing that environmental deprivation or enrichment shapes the brain, there has been increasing interest in understanding how the experience of poverty may shape the brain in humans. In this review, we summarize research on the relationship between socioeconomic status and brain development, focusing on studies published in the last 5 years. Drawing on a conceptual framework informed by animal models, we highlight neural plasticity, epigenetics, material deprivation (eg, cognitive stimulation, nutrient deficiencies), stress (eg, negative parenting behaviors), and environmental toxins as factors that may shape the developing brain. We then summarize the existing evidence for the relationship between child poverty and brain structure and function, focusing on brain areas that support memory, emotion regulation, and higher-order cognitive functioning (ie, hippocampus, amygdala, prefrontal cortex) and regions that support language and literacy (ie, cortical areas of the left hemisphere). We then consider some limitations of the current literature and discuss the implications of neuroscience concepts and methods for interventions in the pediatric medical home.

Academic Achievement Varies With Gestational Age Among Children Born at Term

OBJECTIVE: The goal of this study was to examine the degree to which children born within the “normal term” range of 37 to 41 weeks’ gestation vary in terms of school achievement. METHODS: This study analyzed data from 128 050 singleton births born between 37 and 41 weeks’ gestation in a large US city. Data were extracted from city birth records to assess a number of obstetric, social, and economic variables, at both the individual and community levels. Birth data were then matched with public school records of standardized city-wide third-grade reading and math tests. Specifically, we assessed (1) whether children born within the normal term range of 37 to 41 weeks’ gestation show differences in reading and/or math ability 8 years later as a function of gestational age, and (2) the degree to which a wide range of individual- and community-level social and biological factors mediate this effect. RESULTS: Analyses revealed that gestational age within the normal term range was significantly and positively related to reading and math scores in third grade, with achievement scores for children born at 37 and 38 weeks significantly lower than those for children born at 39, 40, or 41 weeks. This effect was independent of birth weight, as well as a number of other obstetric, social, and economic factors. CONCLUSIONS: Earlier normal term birth may be a characteristic considered by researchers, clinicians, and parents to help identify children who may be at risk for poorer school performance.

Hippocampal volume varies with educational attainment across the life-span

Socioeconomic disparities—and particularly differences in educational attainment—are associated with remarkable differences in cognition and behavior across the life-span. Decreased educational attainment has been linked to increased exposure to life stressors, which in turn have been associated with structural differences in the hippocampus and the amygdala. However, the degree to which educational attainment is directly associated with anatomical differences in these structures remains unclear. Recent studies in children have found socioeconomic differences in regional brain volume in the hippocampus and amygdala across childhood and adolescence. Here we expand on this work, by investigating whether disparities in hippocampal and amygdala volume persist across the life-span. In a sample of 275 individuals from the BRAINnet Foundation database ranging in age from 17 to 87, we found that socioeconomic status (SES), as operationalized by years of educational attainment, moderates the effect of age on hippocampal volume. Specifically, hippocampal volume tended to markedly decrease with age among less educated individuals, whereas age-related reductions in hippocampal volume were less pronounced among more highly educated individuals. No such effects were found for amygdala volume. Possible mechanisms by which education may buffer age-related effects on hippocampal volume are discussed.

Reading Development and Impairment: Behavioral, Social, and Neurobiological Factors

What are the cognitive and neurobiological building blocks necessary for children to acquire literacy, a skill that is crucial for academic and life achievement? In this review we discuss the behavioral and neurobiological evidence concerning the bases of reading development and impairment. The means by which reading achievement may be influenced by the background and experiences that a child brings to the classroom are discussed. Finally, we review a series of experimental studies that have examined the cognitive and neurobiological response prior to and following reading intervention in struggling readers. The importance of appropriate control groups is stressed, as well as the ultimate goal of designing reading interventions that target individual needs.

Higher education is an age‐independent predictor of white matter integrity and cognitive control in late adolescence

Socioeconomic status is an important predictor of cognitive development and academic achievement. Late adolescence provides a unique opportunity to study how the attainment of socioeconomic status (in the form of years of education) relates to cognitive and neural development, during a time when age-related cognitive and neural development is ongoing. During late adolescence it is possible to disambiguate age- and education-related effects on the development of these processes. Here we assessed the degree to which higher educational attainment was related to performance on a cognitive control task, controlling for age. We then used diffusion tensor imaging (DTI) to assess the degree to which white matter microstructure might mediate this relationship. When covarying age, significant associations were found between educational attainment and fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and cingulum bundle (CB). Further, when covarying age, FA in these regions was associated with cognitive control. Finally, mediation analyses revealed that the age-independent association between educational attainment and cognitive control was completely accounted for by FA in these regions. The uncinate fasciculus, a late-myelinated control region not implicated in cognitive control, did not mediate this effect.

Neurocognitive development in socioeconomic context: Multiple mechanisms and implications for measuring socioeconomic status

Socioeconomic status (SES) has been linked to functioning across a variety of neurocognitive domains including language, memory, executive functioning, and social-emotional processing. We review these findings and discuss the ways in which socioeconomic context may shape neural processes such that these skills are supported by different neurobiological pathways in children from lower versus higher SES backgrounds. Moreover, we consider the mechanisms by which SES may be related to specific neurocognitive functions. Specifically, we focus on linguistic exposure and stress as two main pathways through which SES could influence neurocognitive processes and shape relations between the neural and behavioral levels of functioning. Finally, suggestions for conceptualizing and measuring SES in future work are offered.