Socioeconomic status and structural brain development

Associations between Socioeconomic Status, Cognition, and Brain Structure: Evaluating Potential Causal Pathways Through Mechanistic Models of Development

Differences in socioeconomic status (SES) correlate both with differences in cognitive development and in brain structure. Associations between SES and brain measures such as cortical surface area and cortical thickness mediate differences in cognitive skills such as executive function and language. However, causal accounts that link SES, brain, and behavior are challenging because SES is a multidimensional construct: correlated environmental factors, such as family income and parental education, are only distal markers for proximal causal pathways. Moreover, the causal accounts themselves must span multiple levels of description, employ a developmental perspective, and integrate genetic effects on individual differences. Nevertheless, causal accounts have the potential to inform policy and guide interventions to reduce gaps in developmental outcomes. In this article, we review the range of empirical data to be integrated in causal accounts of developmental effects on the brain and cognition associated with variation in SES. We take the specific example of language development and evaluate the potential of a multiscale computational model of development, based on an artificial neural network, to support the construction of causal accounts. We show how, with bridging assumptions that link properties of network structure to magnetic resonance imaging (MRI) measures of brain structure, different sets of empirical data on SES effects can be connected. We use the model to contrast two possible causal pathways for environmental influences that are associated with SES: differences in prenatal brain development and differences in postnatal cognitive stimulation. We then use the model to explore the implications of each pathway for the potential to intervene to reduce gaps in developmental outcomes. The model points to the cumulative effects of social disadvantage on multiple pathways as the source of the poorest response to interventions. Overall, we highlight the importance of implemented models to test competing accounts of environmental influences on individual differences.

Access to quality health resources and environmental toxins affect the relationship between brain structure and BMI in a sample of pre and early adolescents

Background

Environmental resources are related to childhood obesity risk and altered brain development, but whether these relationships are stable or if they have sustained impact is unknown. Here, we utilized a multidimensional index of childhood neighborhood conditions to compare the influence of various social and environmental disparities (SED) on body mass index (BMI)-brain relationships over a 2-year period in early adolescence.

Methods

Data were gathered the Adolescent Brain Cognitive Development Study® (n = 2,970, 49.8% female, 69.1% White, no siblings). Structure magnetic resonance imaging (sMRI), anthropometrics, and demographic information were collected at baseline (9/10-years-old) and the 2-year-follow-up (11/12-years-old). Region of interest (ROIs; 68 cortical, 18 subcortical) estimates of cortical thickness and subcortical volume were extracted from sMRI T1w images using the Desikan atlas. Residential addresses at baseline were used to obtain geocoded estimates of SEDs from 3 domains of childhood opportunity index (COI): healthy environment (COIHE), social/economic (COISE), and education (COIED). Nested, random-effects mixed models were conducted to evaluate relationships of BMI with (1) ROI * COI[domain] and (2) ROI * COI[domain] * Time. Models controlled for sex, race, ethnicity, puberty, and the other two COI domains of non-interest, allowing us to estimate the unique variance explained by each domain and its interaction with ROI and time.

Results

Youth living in areas with lower COISE and COIED scores were heavier at the 2-year follow-up than baseline and exhibited greater thinning in the bilateral occipital cortex between visits. Lower COISE scores corresponded with larger volume of the bilateral caudate and greater BMI at the 2-year follow-up. COIHE scores showed the greatest associations (n = 20 ROIs) with brain-BMI relationships: youth living in areas with lower COIHE had thinner cortices in prefrontal regions and larger volumes of the left pallidum and Ventral DC. Time did not moderate the COIHE x ROI interaction for any brain region during the examined 2-year period. Findings were independent of family income (i.e., income-to-needs).

Conclusion

Collectively our findings demonstrate that neighborhood SEDs for health-promoting resources play a particularly important role in moderating relationships between brain and BMI in early adolescence regardless of family-level financial resources.

Brain-Directed Care: Why Neuroscience Principles Direct PICU Management beyond the ABCs

Major advances in pediatric intensive care (PICU) have led to increased child survival. However, the long-term outcomes among these children following PICU discharge are a concern. Most children admitted to PICU are under five years of age, and the stressors of critical illness and necessary interventions can affect their ability to meet crucial developmental milestones. Understanding the neuroscience of brain development and vulnerability can inform PICU clinicians of new ways to enhance and support the care of these most vulnerable children and families. This review paper first explores the evidence-based neuroscience principles of brain development and vulnerability and the impact of illness and care on children's brains and ultimately wellbeing. Implications for clinical practice and training are further discussed to help optimize brain health in children who are experiencing and surviving a critical illness or injury.

The Critical Roles of Early Development, Stress, and Environment in the Course of Psychosis

Psychotic disorders are highly debilitating with poor prognoses and courses of chronic illness. In recent decades, conceptual models have shaped understanding, informed treatment, and guided research questions. However, these models have classically focused on the adolescent and early adulthood stages immediately preceding onset while conceptualizing early infancy through all of childhood as a unitary premorbid period. In addition, models have paid limited attention to differential effects of types of stress; contextual factors such as local, regional, and country-level characteristics or sociocultural contexts; and the timing of the stressor or environmental risk. This review discusses emerging research suggesting that (a) considering effects specific to neurodevelopmental stages prior to adolescence is highly informative, (b) understanding specific stressors and levels of environmental exposures (i.e., systemic or contextual features) is necessary, and (c) exploring the dynamic interplay between development, levels and types of stressors, and environments can shed new light, informing a specified neurodevelopmental and multifaceted diathesis-stress model.

Conceptualizing the Influence of Social and Structural Determinants of Neurobiology and Mental Health: Why and How Biological Psychiatry Can Do Better at Addressing the Consequences of Inequity

Psychiatry and allied disciplines have recognized the potency of structural and social determinants of mental health, yet there has been scant attention given to the roles of neurobiology in the links between structural and social determinants and mental health. In this article, we make the case for why greater attention must be given to structural and social determinants of biological psychiatry by researchers, practitioners, and policy-makers. After defining these terms and theoretical frameworks for considering their relevance in biological psychiatry, we review empirical research with marginalized and minoritized racial, ethnic, gender, sexual, and economic communities that reveals the ways in which structural and social determinants affect neurobiological functioning with implications for mental health. We give particular emphasis to developmental science and developmentally informed research, because structural and social determinants influence neurobiological adaptation and maturation across the lifespan. We conclude with recommendations for advancing research, practice, and policy that connect biological psychiatry with structural and social determinants of health. Foremost among these is diversifying the ranks of biological psychiatry, from classrooms through laboratories, hospitals, and community health centers. Transforming and advancing the understanding of the structural and social determinants of neurobiology and mental health is most likely to come through transforming the discipline itself.

Blood-derived deoxyribonucleic acid methylation clusters associate with adverse social exposures and endophenotypes of stress-related psychiatric illness in a trauma-exposed cohort of women

Adverse social exposures (ASEs) such as low income, low educational attainment, and childhood/adult trauma exposure are associated with variability in brain region measurements of gray matter volume (GMV), surface area (SA), and cortical thickness (CT). These CNS morphometries are associated with stress-related psychiatric illnesses and represent endophenotypes of stress-related psychiatric illness development. Epigenetic mechanisms, such as 5-methyl-cytosine (5mC), may contribute to the biological embedding of the environment but are understudied and not well understood. How 5mC relates to CNS endophenotypes of psychiatric illness is also unclear. In 97 female, African American, trauma-exposed participants from the Grady Trauma Project, we examined the associations of childhood trauma burden (CTQ), adult trauma burden, low income, and low education with blood-derived 5mC clusters and variability in brain region measurements in the amygdala, hippocampus, and frontal cortex subregions. To elucidate whether peripheral 5mC indexes central nervous system (CNS) endophenotypes of psychiatric illness, we tested whether 73 brain/blood correlated 5mC clusters, defined by networks of correlated 5mC probes measured on Illumina's HumanMethylation Epic Beadchip, mediated the relationship between ASEs and brain measurements. CTQ was negatively associated with rostral middle frontal gyrus (RMFG) SA (β =-0.231, p = 0.041). Low income and low education were also associated with SA or CT in a number of brain regions. Seven 5mC clusters were associated with CTQ (pmin = 0.002), two with low education (pmin = 0.010), and three with low income (pmin = 0.007). Two clusters fully mediated the relation between CTQ and RMFG SA, accounting for 47 and 35% of variability, respectively. These clusters were enriched for probes falling in DNA regulatory regions, as well as signal transduction and immune signaling gene ontology functions. Methylome-network analyses showed enrichment of macrophage migration (p = 9 × 10-8), T cell receptor complex (p = 6 × 10-6), and chemokine-mediated signaling (p = 7 × 10-4) pathway enrichment in association with CTQ. Our results support prior work highlighting brain region variability associated with ASEs, while informing a peripheral inflammation-based epigenetic mechanism of biological embedding of such exposures. These findings could also serve to potentiate increased investigation of understudied populations at elevated risk for stress-related psychiatric illness development.

Home language and literacy environment and its relationship to socioeconomic status and white matter structure in infancy

The home language and literacy environment (HLLE) in infancy has been associated with subsequent pre-literacy skill development and HLLE at preschool-age has been shown to correlate with white matter organization in tracts that subserve pre-reading and reading skills. Furthermore, childhood socioeconomic status (SES) has been linked with both HLLE and white matter organization. It is important to understand whether the relationships between environmental factors such as HLLE and SES and white matter organization can be detected as early as infancy, as this period is characterized by rapid brain development that may make white matter pathways particularly susceptible to these early experiences. Here, we hypothesized that HLLE (1) relates to white matter organization in pre-reading and reading-related tracts in infants, and (2) mediates a link between SES and white matter organization. To test these hypotheses, infants (mean age: 8.6 ± 2.3 months, N = 38) underwent diffusion-weighted imaging MRI during natural sleep. Image processing was performed with an infant-specific pipeline and fractional anisotropy (FA) was estimated from the arcuate fasciculus (AF) and superior longitudinal fasciculus (SLF) bilaterally using the baby automated fiber quantification method. HLLE was measured with the Reading subscale of the StimQ (StimQ-Reading) and SES was measured with years of maternal education. Self-reported maternal reading ability was also quantified and applied to our statistical models as a proxy for confounding genetic effects. StimQ-Reading positively correlated with FA in left AF and to maternal education, but did not mediate the relationship between them. Taken together, these findings underscore the importance of considering HLLE from the start of life and may inform novel prevention and intervention strategies to support developing infants during a period of heightened brain plasticity.

Physical fitness mediates the inverse association between fatness indicators and academic achievement, despite the school vulnerability of adolescents—The Cogni-Action Project

Objective

This study aims to determine the mediating role of physical fitness in the relationship between fatness indicators and academic achievement, exploring the influence of school vulnerability.

Methods

A total of 1,296 Chilean adolescents (aged 10 to 14 years; 50% girls) participated in this study. The global fitness score (GFS) was obtained by adding the three main components of the ALPHA fitness test: cardiorespiratory fitness (CRF), muscular fitness (MF), and speed/agility fitness (SAF). CRF was evaluated through the 20 m shuttle run test; MF by upper and lower limb strength tests; and SAF by the 4 × 10 shuttle run test. BMIz and WHtR were evaluated as general (unspecific) and central (specific) fatness indicators. Academic achievement was established through grades in math, language, and science and their average scores. Multiple mediation analyses were performed according to two models, adjusted for sex, maturity, and schools (model 1), and in model 2, the school vulnerability index (SVI) was added. The SVI is an important proxy of socioeconomic status at the school level, and it was categorized as high-, mid-, or low-SVI. Mediation percentages were calculated, and confidence intervals (bootstrapping) were used to establish significant findings.

Results

CRF, SAF, and GFS mediate the relationship between fatness indicators and academic achievement, both partially and totally (ranging from 12.7 to 59.2%). However, MF did not show any mediation effect. After controlling for SVI, CRF, and GFS, mediation changed from partial to total in the associations between math and science with WHtR. Although SAF contributed to GFS mediation, CRF seems to have the most significant mediation role for all academic achievements, regardless of SVI and the fat indicator studied.

Conclusion

A higher level of general physical fitness, especially CRF, significantly mediates the detrimental influence of fatness on the academic achievement of schoolchildren. This study suggests that physical fitness plays a relevant role in academic and public health, considering the high prevalence and detrimental influence of obesity and school vulnerability in children and adolescents.

Anxiety in children and youth with autism spectrum disorder and the association with amygdala subnuclei structure

Autism spectrum disorder (ASD) is clinically characterized by social and communication difficulties as well as repetitive behaviors. Many children with ASD also suffer from anxiety, which has been associated with alterations in amygdala structure. In this work, the association between amygdala subnuclei volumes and anxiety was assessed in a cohort of 234 participants (mean age = 11.0 years, SD = 3.9, 95 children with ASD, 139 children were non-autistic). Children underwent magnetic resonance imaging. Amygdala subnuclei volumes were extracted automatically. Anxiety was assessed using the Screen for Child Anxiety Related Disorders, the Child Behavior Checklist, and the Strength and Difficulties Questionnaire. Children with ASD had higher anxiety scores relative to non-autistic children on all anxiety measures (all, p < 0.05). Anxiety levels were significantly predicted in children with ASD by right basal (right: B = 0.235, p = 0.002) and paralaminar (PL) (B = −0.99, p = 0.009) volumes. Basal nuclei receive multisensory information from cortical and subcortical areas and have extensive projections within the limbic system while the PL nuclei are involved in emotional processing. Alterations in basal and PL nuclei in children with ASD and the association with anxiety may reflect morphological changes related to in the neurocircuitry of anxiety in ASD.

Lay abstract

Autism spectrum disorder (ASD) is clinically characterized by social communication difficulties as well as restricted and repetitive patterns of behavior. In addition, children with ASD are more likely to experience anxiety compared with their peers who do not have ASD. Recent studies suggest that atypical amygdala structure, a brain region involved in emotions, may be related to anxiety in children with ASD. However, the amygdala is a complex structure composed of heterogeneous subnuclei, and few studies to date have focused on how amygdala subnuclei relate to in anxiety in this population. The current sample consisted of 95 children with ASD and 139 non-autistic children, who underwent magnetic resonance imaging (MRI) and assessments for anxiety. The amygdala volumes were automatically segmented. Results indicated that children with ASD had elevated anxiety scores relative to peers without ASD. Larger basal volumes predicted greater anxiety in children with ASD, and this association was not seen in non-autistic children. Findings converge with previous literature suggesting ASD children suffer from higher levels of anxiety than non-autistic children, which may have important implications in treatment and interventions. Our results suggest that volumetric estimation of amygdala’s subregions in MRI may reveal specific anxiety-related associations in children with ASD.

Socioeconomic deprivation in early life and symptoms of depression and anxiety in young adulthood: mediating role of hippocampal connectivity

BACKGROUND

Experience of early-life socioeconomic deprivation (ELSD) may increase the risk of mental disorders in young adulthood. This association may be mediated by structural and functional alterations of the hippocampus.

METHODS

We conducted a prospective cohort study on 122 participants of the European Longitudinal Study of Pregnancy and Childhood. Information about ELSD was collected via questionnaire from mothers during the first 18 months of participants' lives. At age 23-24, participants underwent examination by structural magnetic resonance imaging, resting-state functional connectivity and assessment of depressive symptoms (Mood and Feelings Questionnaire) and anxiety (Spielberger State-Trait Anxiety Inventory). The association of ELSD with brain outcomes in young adulthood was assessed with correlations, linear regression (adjusting for sex, socioeconomic position and mother's mental health) and moderated mediation analysis.

RESULTS

Higher ELSD was associated with greater depressive symptoms (B = 0.22; p = 0.001), trait anxiety (B = 0.07; p = 0.02) and lower global connectivity of the right hippocampus (B = -0.01; p = 0.02). These associations persisted when adjusted for covariates. In women, lower global connectivity of the right hippocampus was associated with stronger trait anxiety (B = -4.14; p = 0.01). Global connectivity of the right hippocampus as well as connectivity between the right hippocampus and the left middle temporal gyrus mediated the association between ELSD and trait anxiety in women. Higher ELSD correlated with a lower volume of the right hippocampus in men, but the volume of the right hippocampus was not related to mental health.

CONCLUSIONS

Early preventive strategies targeted at children from socioeconomically deprived families may yield long-lasting benefits for the mental health of the population.

Opportunities to Discuss Diversity-Related Topics in Neuroscience Courses

Diversity is a foundational topic in psychology, and APA recommends that diversity is covered across the psychology curriculum. Neuroscience courses face challenges with incorporating diversity-related topics owing to the historical lack of neuroscience research that focuses on diversity and the restricted range of diversity-related topics that neuroscience is typically associated with (i.e., health and disability status). This may limit students' learning of neuroscience's contributions towards understanding diversity. We review some specific examples of diversity-related topics that can be incorporated into neuroscience courses. These examples have been selected to include topics across the three major content domains of neuroscience (cellular/molecular, neuroanatomy/systems, and cognitive/behavioral), as well as across multiple diversity-related topics. Neuroscience instructors can use these examples to incorporate greater coverage of diversity-related topics within their courses and/or as points of inspiration for their own curricular additions. Providing systematic coverage of diversity-related topics in neuroscience courses highlights the ways neuroscience advances our understanding of human diversity and contributes to the educational objectives of psychology and neuroscience programs.

Early Childhood Development and Social Determinants

In human beings, the development of a child involves biological, emotional, and psychological changes that happen between birth and the conclusion of adolescence. Childhood is divided into three stages: early childhood, middle childhood, and late childhood (preadolescence). Early childhood is typically from infancy to six years of age. The methods for maintaining health and dealing with already-existing sicknesses and the social and economic settings in which children are born, grow up, live, and eventually work are referred to as the social determinants of health. Despite advances in health, child malnutrition remains a problem salutariness (severe) issue with massive human and economic resource implications. There is currently a growing corpus of research on how early development influences a child’s success later in life. From conception to two years of age, the first 1,000 days of life are becoming more well-recognized as important for the development of brain circuits that lead to linguistic, cognitive, and socio-emotional abilities, all of which are predictors of later-life labor market outcomes. The social patterning of health, sickness, and illness can be influenced by the social determinants of a child's health. This can also influence a person's overall well-being and functioning throughout their lifetime factors of a child's health, early childhood care, and development from an ecological standpoint, and as planned, a participatory approach in early childhood care and development is implemented. The social determinants of health are the elements that cause positive or negative changes in health or alter disease risks. The social determinants of health, which are different from medical treatment, can be altered by social policy. Social gradients and health equality are ideas that are related to understanding how social factors impact health.

Radically reframing studies on neurobiology and socioeconomic circumstances: A call for social justice-oriented neuroscience

Socioeconomic circumstances are associated with symptoms and diagnostic status of nearly all mental health conditions. Given these robust relationships, neuroscientists have attempted to elucidate how socioeconomic-based adversity "gets under the skin." Historically, this work emphasized individual proxies of socioeconomic position (e.g., income, education), ignoring the effects of broader socioeconomic contexts (e.g., neighborhood socioeconomic disadvantage) which may uniquely contribute to chronic stress. This omission represented a disconnect between neuroscience and other allied fields that have recognized health is undeniably linked to interactions between systems of power and individual characteristics. More recently, neuroscience work has considered how sociopolitical context affects brain structure and function; however, the products of this exciting line of research have lacked critical sociological and historical perspectives. While empirical evidence on this topic is burgeoning, the cultural, ethical, societal, and legal implications of this work have been elusive. Although the mechanisms by which socioeconomic circumstances impact brain structure and function may be similar across people, not everyone is exposed to these factors at similar rates. Individuals from ethnoracially minoritized groups are disproportionally exposed to neighborhood disadvantage. Thus, socioeconomic inequities examined in neuroscience research are undergirding with other forms of oppression, namely structural racism. We utilize a holistic, interdisciplinary approach to interpret findings from neuroscience research and interweave relevant theories from the fields of public health, social sciences, and Black feminist thought. In this perspective piece, we discuss the complex relationship that continues to exist between academic institutions and underserved surrounding communities, acknowledging the areas in which neuroscience research has historically harmed and/or excluded structurally disadvantaged communities. We conclude by envisioning how this work can be used; not just to inform policymakers, but also to engage and partner with communities and shape the future direction of human neuroscience research.

The Association Between Neighborhood Poverty and Hippocampal Volume Among Individuals at Clinical High-Risk for Psychosis: The Moderating Role of Social Engagement

Reductions in hippocampal volume (HV) have been associated with both prolonged exposure to stress and psychotic illness. This study sought to determine whether higher levels of neighborhood poverty would be associated with reduced HV among individuals at clinical high-risk for psychosis (CHR-P), and whether social engagement would moderate this association. This cross-sectional study included a sample of participants (N  =  174, age-range = 12-33 years, 35.1% female) recruited for the second phase of the North American Prodrome Longitudinal Study. Generalized linear mixed models tested the association between neighborhood poverty and bilateral HV, as well as the moderating role of social engagement on this association. Higher levels of neighborhood poverty were associated with reduced left (β  =  -0.180, P  =  .016) and right HV (β  =  -0.185, P  =  .016). Social engagement significantly moderated the relation between neighborhood poverty and bilateral HV. In participants with lower levels of social engagement (n  =  77), neighborhood poverty was associated with reduced left (β  =  -0.266, P  =  .006) and right HV (β = -0.316, P  = .002). Among participants with higher levels of social engagement (n = 97), neighborhood poverty was not significantly associated with left (β  =  -0.010, P  =  .932) or right HV (β  =  0.087, P  =  .473). In this study, social engagement moderated the inverse relation between neighborhood poverty and HV. These findings demonstrate the importance of including broader environmental influences and indices of social engagement when conceptualizing adversity and potential interventions for individuals at CHR-P.

The association between sleep disturbances and neurocognitive function in pediatric sickle cell disease

BACKGROUND AND OBJECTIVE

Youth with sickle cell disease (SCD) without neurological complications continue to be at increased risk of neurocognitive difficulties. Nocturnal hypoxemia is associated with neurocognitive outcomes and has been identified as a chronic complication in youth with SCD. The objective of this study was to assess the relationship between sleep disturbances and neurocognitive functioning in youth with SCD, while taking into account demographic and socioeconomic factors.

METHODS

Youth with SCD were identified through retrospective chart review who underwent a standardized polysomnography (PSG) and completed a neuropsychological testing battery to assess cognitive skills, including verbal comprehension, working memory, processing speed, and cognitive flexibility. Questionnaires were also collected to assess parent-reported concerns with their youth's executive and adaptive skills.

RESULTS

Twenty-seven youth with SCD, ages 6-17, were identified who completed both a PSG and neuropsychological testing. Results demonstrated that verbal comprehension decreased by 2.37 standard points for every unit decrease in mean nocturnal oxygen saturation (SpO2) (p = 0.031). Working memory was also found to decrease by 1.46 standard points for each 1% increase in time spent under 90% oxygen saturation (pTST SpO2 < 90%) (p = 0.030). Sleep parameters did not significantly predict other cognitive scores or parent-reported executive or behavioral ratings.

CONCLUSION

Our study found that sleep disturbance, mean nocturnal SpO2 and pTST SpO2 < 90%, significantly affected verbal comprehension and working memory performance, respectively. Overall, these findings have the potential to identify sleep needs in youth with SCD to promote sleep-targeted interventions as a modifiable factor to reduce neurocognitive deficits.

Mechanical Properties of the Developing Brain are Associated with Language Input and Vocabulary Outcome

The quality of language that children hear in their environment is associated with the development of language-related brain regions, in turn promoting vocabulary knowledge. Although informative, it remains unknown how these environmental influences alter the structure of neural tissue and subsequent vocabulary outcomes. The current study uses magnetic resonance elastography (MRE) to examine how children's language environments underlie brain tissue mechanical properties, characterized as brain tissue stiffness and damping ratio, and promote vocabulary knowledge. Twenty-five children, ages 5-7, had their audio and video recorded while engaging in a play session with their parents. Children also completed the Picture Vocabulary Task (from NIH Toolbox) and participated in an MRI, where MRE and anatomical images were acquired. Higher quality input was associated with greater stiffness in the bilateral inferior frontal gyrus and right superior temporal gyrus, whereas greater vocabulary knowledge was associated with lower damping ratio in the right inferior frontal gyrus. These findings suggest changes in neural tissue composition are sensitive to malleable aspects of the environment, whereas tissue organization is more strongly associated with vocabulary outcome. Notably, these associations were independent of maternal education, suggesting more proximal measures of a child's environment may be the source of differences in neural tissue structure underlying variability in vocabulary outcomes.

The Affective Neuroscience of Poverty

Growing up in poverty is associated with a heightened risk for mental and physical health problems across the life span, and there is a growing recognition of the role that social determinants of health play in driving these outcomes and inequities. How do the social conditions of poverty get under the skin to influence biology, and through what mechanisms do the stressors of poverty generate risk for a broad range of health problems? The growing field examining the neuroscience of socioeconomic status (SES) proposes that the brain is an entry point or pathway through which poverty and adversity become embedded in biology to generate these disparities. To date, however, the majority of research on the neuroscience of SES has focused on cognitive or executive control processes. However, the relationship between SES and brain systems involved in affective or emotional processes may be especially important for understanding social determinants of health. Accordingly, this Special Focus on The Affective Neuroscience of Poverty invited contributions from authors examining the relationship between SES and brain systems involved in generating and regulating emotions. In this editorial introduction, we (a) provide an overview of the neuroscience of SES; (b) introduce each of the articles in this Special Focus; and (c) discuss the scientific, treatment, and policy implications of studying the affective neuroscience of poverty.

Machine Learning to Predict Executive Function in Adolescents with Repaired d-Transposition of the Great Arteries, Tetralogy of Fallot, and Fontan Palliation

OBJECTIVE

To identify predictors of impaired executive function in adolescents after surgical repair of critical congenital heart disease (CHD).

STUDY DESIGN

We analyzed patient factors, medical and surgical history, and family social class from 3 single-center studies of adolescents with d-transposition of the great arteries (d-TGA), tetralogy of Fallot (TOF), and Fontan repair. Machine learning models were developed using recursive partitioning to predict an executive function composite score based on five subtests (population mean 10, SD 3) of the Delis-Kaplan Executive Function System.

RESULTS

The sample included 386 patients (139 d-TGA, 91 TOF, 156 Fontan) of age 15.1 ± 2.1 (mean ± SD) years and an executive function composite score of 8.6 ± 2.4. Family social class emerged as the most important predictive factor. The lowest (worst) mean executive function score (5.3) occurred in patients with low to medium social class (Hollingshead index <56) with one or more neurologic events and a diagnosis of TOF. The highest (best) mean score (9.7) occurred in subjects with high social class (Hollingshead index ≥56) and shorter duration of deep hypothermic circulatory arrest. Other factors predicting lower executive function scores included low birth weight and a greater number of catheterizations.

CONCLUSIONS

In regression tree modeling, family social class was the strongest predictor of executive function in adolescents with critical CHD, even in the presence of medical risk factors. Additional predictors included CHD diagnosis, birth weight, neurologic events, and number of procedures. These data highlight the importance of social class in mitigating risks of executive dysfunction in CHD.

Paid maternal leave is associated with infant brain function at 3 months of age

The first months of life are critical for establishing neural connections relevant for social and cognitive development. Yet, the United States lacks a national policy of paid family leave during this important period of brain development. This study examined associations between paid leave and infant electroencephalography (EEG) at 3 months in a sociodemographically diverse sample of families from New York City (N = 80; 53 males; 48% Latine; data collection occurred 05/2018-12/2019). Variable-centered regression results indicate that paid leave status was related to differences in EEG power (ps < .02, R² s > .12). Convergent results from person-centered latent profile analyses demonstrate that mothers with paid leave were 7.39 times as likely to have infants with EEG profiles characterized by increased higher-Hz power (95% CI, 1.9-36.9), potentially reflecting more mature patterns of brain activity.

Interpersonal Family Dynamics Relate to Hippocampal CA Subfield Structure

Social environments that are extremely enriched or adverse can influence hippocampal volume. Though most individuals experience social environments that fall somewhere in between these extremes, substantially less is known about the influence of normative variation in social environments on hippocampal structure. Here, we examined whether hippocampal volume tracks normative variation in interpersonal family dynamics in 7- to 12-year-olds and adults recruited from the general population. We focused on interpersonal family dynamics as a prominent feature of one's social world. Given evidence that CA1 and CA2 play a key role in tracking social information, we related individual hippocampal subfield volumes to interpersonal family dynamics. More positive perceptions of interpersonal family dynamics were associated with greater CA1 and CA2/3 volume regardless of age and controlling for socioeconomic status. These data suggest that CA subfields are sensitive to normative variation in social environments and identify interpersonal family dynamics as an impactful environmental feature.

Trajectories of socioeconomic inequality in early child development: a cohort analysis

Background

Addressing socioeconomic inequalities in early child development (ECD) is key to reducing the intergenerational transmission of health inequalities. Yet, little is known about how socioeconomic inequalities in ECD develop over the course of childhood. Our study aimed to describe how inequalities in ECD by maternal education develop from infancy to middle childhood.

Methods

We used data from Generation R, a prospective population-based cohort study in The Netherlands. Language skills were measured at ages 1, 1.5, 2, 3, and 4 years, using the Minnesota Child Development Inventory. Socioemotional (i.e. internalizing and externalizing) problems were measured at ages 1.5, 3, 5 and 9 years using the Child Behavior Checklist. We estimated inequalities in language skills and socioemotional problems across the above-mentioned ages, using linear mixed models with standardized scores at each wave. We used maternal education as indicator of socioeconomic position.

Results

Children of less educated mothers had more reported internalizing (B = 0.72, 95%CI = 0.51;0.95) and externalizing (B = 0.25, 95%CI = 0.10;0.40) problems at age 1.5 years, but better (caregiver reported) language skills at 1 year (B = 0.50, 95%CI = 0.36;0.64) than children of high educated mothers. Inequalities in internalizing and externalizing problems decreased over time. Inequalities in language scores reversed at age 2, and by the time children were 4 years old, children of less educated mothers had substantially lower language skills than children of high educated mothers (B = -0.38, 95%CI = -0.61;-0.15).

Conclusions

Trajectories of socioeconomic inequality in ECD differ by developmental domain: whereas inequalities in socioemotional development decreased over time, inequalities increased for language development. Children of less educated mothers are at a language disadvantage even before entering primary education, providing further evidence that early interventions are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-022-01675-8.

Population variation in social brain morphology: Links to socioeconomic status and health disparity

Health disparity across layers of society involves reasons beyond the healthcare system. Socioeconomic status (SES) shapes people's daily interaction with their social environment and is known to impact various health outcomes. Using generative probabilistic modeling, we investigate health satisfaction and complementary indicators of socioeconomic lifestyle in the human social brain. In a population cohort of ~10,000 UK Biobank participants, our first analysis probed the relationship between health status and subjective social standing (i.e., financial satisfaction). We identified volume effects in participants unhappy with their health in regions of the higher associative cortex, especially the dorsomedial prefrontal cortex (dmPFC) and bilateral temporo-parietal junction (TPJ). Specifically, participants in poor subjective health showed deviations in dmPFC and TPJ volume as a function of financial satisfaction. The second analysis on health status and objective social standing (i.e., household income) revealed volume deviations in regions of the limbic system for individuals feeling unhealthy. In particular, low-SES participants dissatisfied with their health showed deviations in volume distributions in the amygdala and hippocampus bilaterally. Thus, our population-level evidence speaks to the possibility that health status and socioeconomic position have characteristic imprints in social brain differentiation.

Women's health: optimal nutrition throughout the lifecycle

Sex differences are an important consideration when researching and establishing policies for nutrition and optimal health. For women's health, there are important physiologic, neurologic, and hormonal distinctions throughout the lifecycle that impact nutritional needs. Distinct from those for men, these nutritional needs must be translated into appropriate nutrition policy that aims to not only avoid overt nutritional deficiency, but also to promote health and minimize risk for chronic disease. Through a series of webinars, scientific experts discussed the advances in the understanding of the unique nutritional needs, challenges and opportunities of the various life stages for women across the life course and identified emerging nutritional interventions that may be beneficial for women. Nevertheless, there is concern that existing nutrition policy intended for women's health is falling short with examples of programs that are focused more on delivering calories than achieving optimal nutrition. To be locally effective, targeted nutrition needs to offer different proposals for different cultural, socio-economic, and geographic communities, and needs to be applicable at all stages of growth and development. There must be adequate access to nutritious foods, and the information to understand and implement proven nutritional opportunities. Experts provided recommendations for improvement of current entitlement programs that will address accessibility and other social and environmental issues to support women properly throughout the lifecycle.

From zero to thrive: A model of cross-system and cross-sector relational health to promote early childhood development across the child-serving ecosystem

Early relational health between caregivers and children is foundational for child health and well-being. Children and caregivers are also embedded within multiple systems and sectors, or a "child-serving ecosystem", that shapes child development. Although the COVID-19 pandemic has made this embeddedness abundantly clear, systems remain siloed and lack coordination. Fostering relational health amongst layers of this ecosystem may be a way to systematically support young children and families who are facing adversity. We integrate theory, examples, and empirical findings to develop a conceptual model informed by infant mental health and public health frameworks that illustrates how relational health across the child-serving ecosystem may promote child health and well-being at a population level. Our model articulates what relational health looks like across levels of this ecosystem from primary caregiver-child relationships, to secondary relationships between caregivers and child-serving systems, to tertiary relationships among systems that shape child outcomes directly and indirectly. We posit that positive relational health across levels is critical for promoting child health and well-being broadly. We provide examples of evidence-based approaches that address primary, secondary, and tertiary relational health, and suggest ways to promote relational health through cross-sector training and psychoeducation in the science of early development. This model conceptualizes relational health across the child-serving ecosystem and can serve as a template for promoting child health and well-being in the context of adversity.

T1w/T2w Ratio and Cognition in 9-to-11-Year-Old Children

Childhood is a period of extensive cortical and neural development. Among other things, axons in the brain gradually become more myelinated, promoting the propagation of electrical signals between different parts of the brain, which in turn may facilitate skill development. Myelin is difficult to assess in vivo, and measurement techniques are only just beginning to make their way into standard imaging protocols in human cognitive neuroscience. An approach that has been proposed as an indirect measure of cortical myelin is the T1w/T2w ratio, a contrast that is based on the intensities of two standard structural magnetic resonance images. Although not initially intended as such, researchers have recently started to use the T1w/T2w contrast for between-subject comparisons of cortical data with various behavioral and cognitive indices. As a complement to these earlier findings, we computed individual cortical T1w/T2w maps using data from the Adolescent Brain Cognitive Development study (N = 960; 449 females; aged 8.9 to 11.0 years) and related the T1w/T2w maps to indices of cognitive ability; in contrast to previous work, we did not find significant relationships between T1w/T2w values and cognitive performance after correcting for multiple testing. These findings reinforce existent skepticism about the applicability of T1w/T2w ratio for inter-individual comparisons.

Do your eye movements reveal your performance on an IQ test? A study linking eye movements and socio-demographic information to fluid intelligence

Understanding the main factors contributing to individual differences in fluid intelligence is one of the main challenges of psychology. A vast body of research has evolved from the theoretical framework put forward by Cattell, who developed the Culture-Fair IQ Test (CFT 20-R) to assess fluid intelligence. In this work, we extend and complement the current state of research by analysing the differential and combined relationship between eye-movement patterns and socio-demographic information and the ability of a participant to correctly solve a CFT item. Our work shows that a participant’s eye movements while solving a CFT item contain discriminative information and can be used to predict whether the participant will succeed in solving the test item. Moreover, the information related to eye movements complements the information provided by socio-demographic data when it comes to success prediction. In combination, both types of information yield a significantly higher predictive performance than each information type individually. To better understand the contributions of features related to eye movements and socio-demographic information to predict a participant’s success in solving a CFT item, we employ state-of-the-art explainability techniques and show that, along with socio-demographic variables, eye-movement data. Especially the number of saccades and the mean pupil diameter, significantly increase the discriminating power. The eye-movement features are likely indicative of processing efficiency and invested mental effort. Beyond the specific contribution to research on how eye movements can serve as a means to uncover mechanisms underlying cognitive processes, the findings presented in this work pave the way for further in-depth investigations of factors predicting individual differences in fluid intelligence.

Person-specific connectivity mapping uncovers differences of bilingual language experience on brain bases of attention in children

Bilingualism influences children's cognition, yet bilinguals vary greatly in their dual-language experiences. To uncover sources of variation in bilingual and monolingual brain function, the present study used standard analysis and innovative person-specific connectivity models combined with a data-driven grouping algorithm. Children (ages 7-9; N = 52) completed a visuo-spatial attention task while undergoing functional near-infrared spectroscopy neuroimaging. Both bilingual and monolingual groups performed similarly, and engaged bilateral frontal and parietal regions. However, bilinguals showed greater brain activity than monolinguals in left frontal and parietal regions. Connectivity models revealed two empirically-derived subgroups. One subgroup was composed of monolinguals and bilinguals who were more English dominant, and showed left frontal-parietal connections. The other was composed of bilinguals who were balanced in their dual-language abilities and showed left frontal lobe connections. The findings inform how individual variation in early language experiences influences children's emerging cortical networks for executive function, and reveal efficacy of data-driven approaches.

Effects of a statewide pre-kindergarten program on children's achievement and behavior through sixth grade

As state-funded pre-kindergarten (pre-K) programs expand, it is critical to investigate their short- and long-term effects. This article presents the results through sixth grade of a longitudinal randomized control study of the effects of a scaled-up, state-supported pre-K program. The analytic sample includes 2,990 children from low-income families who applied to oversubscribed pre-K program sites across the state and were randomly assigned to offers of admission or a wait list control. Data through sixth grade from state education records showed that the children randomly assigned to attend pre-K had lower state achievement test scores in third through sixth grades than control children, with the strongest negative effects in sixth grade. A negative effect was also found for disciplinary infractions, attendance, and receipt of special education services, with null effects on retention. The implications of these findings for pre-K policies and practices are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

School Climate, Cortical Structure, and Socioemotional Functioning: Associations across Family Income Levels

School climates are important for children's socioemotional development and may also serve as protective factors in the context of adversity. Nevertheless, little is known about the potential neural mechanisms of such associations, as there has been limited research concerning the relation between school climate and brain structure, particularly for brain regions relevant for mental health and socioemotional functioning. Moreover, it remains unclear whether the role of school climate differs depending on children's socioeconomic status. We addressed these questions in baseline data for 9- to 10-year-olds from the Adolescent Brain and Cognitive Development study (analytic sample for socioemotional outcomes, n = 8,887), conducted at 21 sites across the United States. Cortical thickness, cortical surface area, and subcortical volume were derived from T1-weighted brain magnetic resonance imaging. School climate was measured by youth report, and socioemotional functioning was measured by both youth and parent report. A positive school climate and higher family income were associated with lower internalizing and externalizing symptoms, with no evidence of moderation. There were no associations between school climate and cortical thickness or subcortical volume, although family income was positively associated with hippocampal volume. For cortical surface area, however, there was both a positive association with family income and moderation: There was an interaction between school climate and income for total cortical surface area and locally in the lateral orbitofrontal cortex. In all cases, there was an unexpected negative association between school climate and cortical surface area in the lower-income group. Consequently, although the school climate appears to be related to better socioemotional function for all youth, findings suggest that the association between a positive school environment and brain structure only emerges in the context of socioeconomic stress and adversity. Longitudinal data are needed to understand the role of these neural differences in socioemotional functioning over time.

Resilience to COVID-19: Socioeconomic Disadvantage Associated With Positive Caregiver-Youth Communication and Youth Preventative Actions

Socioeconomic disadvantage is associated with larger COVID-19 disease burdens and pandemic-related economic impacts. We utilized the longitudinal Adolescent Brain Cognitive Development Study to understand how family- and neighborhood-level socioeconomic disadvantage relate to disease burden, family communication, and preventative responses to the pandemic in over 6,000 youth-caregiver dyads. Data were collected at three timepoints (May-August 2020). Here, we show that both family- and neighborhood-level disadvantage were associated with caregivers' reports of greater family COVID-19 disease burden, less perceived exposure risk, more frequent caregiver-youth conversations about COVID-19 risk/prevention and reassurance, and greater youth preventative behaviors. Families with more socioeconomic disadvantage may be adaptively incorporating more protective strategies to reduce emotional distress and likelihood of COVID-19 infection. The results highlight the importance of caregiver-youth communication and disease-preventative practices for buffering the economic and disease burdens of COVID-19, along with policies and programs that reduce these burdens for families with socioeconomic disadvantage.

Spatial working memory is disparately interrelated with social status through different developmental stages in rats

Social life necessitates cognitive competence to meet the dynamic demands of social development. The formation of dominance hierarchy is a general phenomenon in social groups. As an essential element of executive and cognitive function, working memory could influence and be influenced by social status in a dominance hierarchy. However, the direction and degree of the association between them through different developmental stages remain unclear. To address this issue and clarify the "cause or consequence" problem, we investigated the spatial working memory performance in a Y-maze and Morris water maze in home-caged sibling Wistar rats (N = 26 cages, three rats/cage) through three stages of their life: before (week 7), during (week 10), and after (week 20) assumed timings of the social dominance hierarchy formation (SDHF). We used the social dominance tube test during the assumed time of hierarchy formation (weeks 9-11) to measure the relative dominance status in each cage. Here, we found that higher working memory index before SDHF could be predictive of later acquisition of higher social status. Working memory performance declined for all animals during SDHF, in which agonistic conflicts are increased. However, living within an established hierarchical social network for several weeks deteriorated the working memory performance of dominant and middle-ranked animals, while the performance of subordinates improved and got significantly better than higher-ranked animals. In conclusion, while working memory and social status were correlated positively before dominance hierarchy formation, there was a trade-off between them after the formation of it. In contrast to the common view, these results highlight the adverse effect of higher social status on cognitive behavior.

Brain structural correlates of upward social mobility in ethnic minority individuals

PURPOSE

Perigenual anterior cingulate cortex (pACC) is a neural convergence site for social stress-related risk factors for mental health, including ethnic minority status. Current social status, a strong predictor of mental and somatic health, has been related to gray matter volume in this region, but the effects of social mobility over the lifespan are unknown and may differ in minorities. Recent studies suggest a diminished health return of upward social mobility for ethnic minority individuals, potentially due to sustained stress-associated experiences and subsequent activation of the neural stress response system.

METHODS

To address this issue, we studied an ethnic minority sample with strong upward social mobility. In a cross-sectional design, we examined 64 young adult native German and 76 ethnic minority individuals with comparable sociodemographic attributes using whole-brain structural magnetic resonance imaging.

RESULTS

Results showed a significant group-dependent interaction between perceived upward social mobility and pACC gray matter volume, with a significant negative association in the ethnic minority individuals. Post-hoc analysis showed a significant mediation of the relationship between perceived upward social mobility and pACC volume by perceived chronic stress, a variable that was significantly correlated with perceived discrimination in our ethnic minority group.

CONCLUSION

Our findings extend prior work by pointing to a biological signature of the "allostatic costs" of socioeconomic attainment in socially disadvantaged upwardly mobile individuals in a key neural node implicated in the regulation of stress and negative affect.

The Effect of Socioeconomic Disparities on Prefrontal Activation in Initiating Joint Attention: A Functional Near-Infrared Spectroscopy Evidence From Two Socioeconomic Status Groups

Low socioeconomic status (SES) may generally have a long-lasting negative effect on cognitive development, and show deficits in the development of executive functions. However, it is unclear whether there is an SES-dependent disparity in the functional brain development of the prefrontal cortex. By collecting task-related functional near-infrared spectroscopy (fNIRS) data and behavioral data (e.g., intelligence, language, home reading environment (HRE), family income, and parental education level), the current study aimed to detect whether the SES of preschool children (N = 86) is associated with prefrontal activation during the joint attention task. Results verified that low-SES children show lower right prefrontal activation during joint attention than Relatively High-SES children. In addition, our findings confirmed the mediating effect of HRE on the association between SES and brain activation during joint attention, as well as that between SES and language ability. These results suggest that SES contributes to functional development of the prefrontal regions, and the improvement of HRE could be a potential strategy to intervene SES-related disparities on child development.

Differential Developmental Associations of Material Hardship Exposure and Adolescent Amygdala-Prefrontal Cortex White Matter Connectivity

Accumulating literature has linked poverty to brain structure and function, particularly in affective neural regions; however, few studies have examined associations with structural connections or the importance of developmental timing of exposure. Moreover, prior neuroimaging studies have not used a proximal measure of poverty (i.e., material hardship, which assesses food, housing, and medical insecurity) to capture the lived experience of growing up in harsh economic conditions. The present investigation addressed these gaps collectively by examining the associations between material hardship (ages 1, 3, 5, 9, and 15 years) and white matter connectivity of frontolimbic structures (age of 15 years) in a low-income sample. We applied probabilistic tractography to diffusion imaging data collected from 194 adolescents. Results showed that material hardship related to amygdala-prefrontal, but not hippocampus-prefrontal or hippocampus-amygdala, white matter connectivity. Specifically, hardship during middle childhood (ages 5 and 9 years) was associated with greater connectivity between the amygdala and dorsomedial pFC, whereas hardship during adolescence (age of 15 years) was related to reduced amygdala-orbitofrontal (OFC) and greater amygdala-subgenual ACC connectivity. Growth curve analyses showed that greater increases of hardship across time were associated with both greater (amygdala-subgenual ACC) and reduced (amygdala-OFC) white matter connectivity. Furthermore, these effects remained above and beyond other types of adversity, and greater hardship and decreased amygdala-OFC connectivity were related to increased anxiety and depressive symptoms. Results demonstrate that the associations between material hardship and white matter connections differ across key prefrontal regions and developmental periods, providing support for potential windows of plasticity for structural circuits that support emotion processing.

Brain morphometry and diminished physical growth in Bangladeshi children growing up in extreme poverty: A longitudinal study

Diminished physical growth is a common marker of malnutrition and it affects approximately 200 million children worldwide. Despite its importance and prevalence, it is not clear whether diminished growth relates to brain development and general cognitive ability. Further, diminished growth is more common in areas of extreme poverty, raising the possibility that it may mediate previously shown links between socioeconomic status (SES) and brain structure. To address these gaps, 79 children growing up in an extremely poor, urban area of Bangladesh underwent MRI at age six years. Structural brain images were submitted to Mindboggle software, a Docker-compliant and high-reproducibility tool for tissue segmentation and regional estimations of volume, surface area, cortical thickness, sulcal depth, and mean curvature. Diminished growth predicted brain morphometry and mediated the link between SES and brain morphometry most consistently for subcortical and white matter subcortical volumes. Meanwhile, brain volume in left pallidum and right ventral diencephalon mediated the relationship between diminished growth and full-scale IQ. These findings offer malnutrition as one possible pathway through which SES affects brain development and general cognitive ability in areas of extreme poverty.

Developmental Changes in Dynamic Functional Connectivity From Childhood Into Adolescence

The longitudinal study of typical neurodevelopment is key for understanding deviations due to specific factors, such as psychopathology. However, research utilizing repeated measurements remains scarce. Resting-state functional magnetic resonance imaging (MRI) studies have traditionally examined connectivity as 'static' during the measurement period. In contrast, dynamic approaches offer a more comprehensive representation of functional connectivity by allowing for different connectivity configurations (time varying connectivity) throughout the scanning session. Our objective was to characterize the longitudinal developmental changes in dynamic functional connectivity in a population-based pediatric sample. Resting-state MRI data were acquired at the ages of 10 (range 8-to-12, n = 3,327) and 14 (range 13-to-15, n = 2,404) years old using a single, study-dedicated 3 Tesla scanner. A fully-automated spatially constrained group-independent component analysis (ICA) was applied to decompose multi-subject resting-state data into functionally homogeneous regions. Dynamic functional network connectivity (FNC) between all ICA time courses were computed using a tapered sliding window approach. We used a k-means algorithm to cluster the resulting dynamic FNC windows from each scan session into five dynamic states. We examined age and sex associations using linear mixed-effects models. First, independent from the dynamic states, we found a general increase in the temporal variability of the connections between intrinsic connectivity networks with increasing age. Second, when examining the clusters of dynamic FNC windows, we observed that the time spent in less modularized states, with low intra- and inter-network connectivity, decreased with age. Third, the number of transitions between states also decreased with age. Finally, compared to boys, girls showed a more mature pattern of dynamic brain connectivity, indicated by more time spent in a highly modularized state, less time spent in specific states that are frequently observed at a younger age, and a lower number of transitions between states. This longitudinal population-based study demonstrates age-related maturation in dynamic intrinsic neural activity from childhood into adolescence and offers a meaningful baseline for comparison with deviations from typical development. Given that several behavioral and cognitive processes also show marked changes through childhood and adolescence, dynamic functional connectivity should also be explored as a potential neurobiological determinant of such changes.

Neural impact of neighborhood socioeconomic disadvantage in traumatically injured adults

Nearly 14 percent of Americans live in a socioeconomically disadvantaged neighborhood. Lower individual socioeconomic position (iSEP) has been linked to increased exposure to trauma and stress, as well as to alterations in brain structure and function; however, the neural effects of neighborhood SEP (nSEP) factors, such as neighborhood disadvantage, are unclear. Using a multi-modal approach with participants who recently experienced a traumatic injury (N = 185), we investigated the impact of neighborhood disadvantage, acute post-traumatic stress symptoms, and iSEP on brain structure and functional connectivity at rest. After controlling for iSEP, demographic variables, and acute PTSD symptoms, nSEP was associated with decreased volume and alterations of resting-state functional connectivity in structures implicated in affective processing, including the insula, ventromedial prefrontal cortex, amygdala, and hippocampus. Even in individuals who have recently experienced a traumatic injury, and after accounting for iSEP, the impact of living in a disadvantaged neighborhood is apparent, particularly in brain regions critical for experiencing and regulating emotion. These results should inform future research investigating how various levels of socioeconomic circumstances may impact recovery after a traumatic injury as well as policies and community-developed interventions aimed at reducing the impact of socioeconomic stressors.

Assessing the Inequality of Early Child Development in China - A Population-Based Study

Background

As a country with the second largest child population in the world, China has little population-level evidence on who has been left behind in early childhood development (ECD). Knowledge of inequalities in ECD will inform the Chinese government in policies on promoting ECD and guide global-level monitoring on ECD progress.

Methods

Using data from the first wave of ECD surveys conducted in China at the least-developed region, most-developed region, and a megacity (Shanghai) in 2017 and 2018, we measured population-level ECD with early Human Capability Index for a total of 63,559 children aged 36-59 months old. A child was classified as developmentally on track if his/her overall development score was above the 20^th percentile of the pooled populations. We measured inequalities in ECD with the absolute inequality in five domains: gender/sex, family income, maternal schooling, residential Hukou, and migrant- or left-behind status. Besides observed inequalities, we used a multilevel logistic regression model to generate adjusted inequalities.

Findings

Children developmentally on track ranges from 71% (95% CI 70 to 72%) in the least-developed region, 82% (95% CI 81 to 83%) in the most-developed region, and 86% (95% CI 85 to 87%) in Shanghai. Significant unadjusted inequalities in ECD were observed in all five dimensions. After controlling for other socioeconomic factors, significant differences remained in three dimensions: those living in the poorest families, or with lower maternal schooling, or boys were less likely to be developmentally on track than their counterparts (lower by 10[95% CI 8 to 11]-15[95% CI 13 to 17], 7[95% CI 5 to 10]-10[95% CI 7 to 12], and 5[95% CI 4 to 6]-6[95% CI 5 to 8] percentage points respectively).

Interpretation

Efforts of reducing ECD inequalities in China shall focus primarily on reducing poverty and improving maternal education.

Funding

National Natural Science Foundation of China (81773443), Shanghai Committee of Science and Technology (2018SHZDZX05), Shanghai Municipal Health Commission (GWV-10.1-XK07; GDEK201708), Shanghai Education Committee, Chinese Social Science Foundation (BFA140046), Macao Tong Chai Charity Association, Beijing Sany Charitable Foundation, China Medical Board (#20-388), UNICEF, Faculty Grant of Brigham & Women's Hospital, Economic and Social Research Council [grant reference number ES/T003936/1’] as a UKRI Collective Fund Award “UKRI GCRF Harnessing the Power of Global Data to Support Young Children's Learning and Development Collaborative."

Timing-specific associations between income-to-needs ratio and hippocampal and amygdala volumes in middle childhood: A preliminary study

It is well known that financial disadvantage is associated with alterations in brain development in regions critical to socioemotional well-being such as the hippocampus and the amygdala. Yet little is known about whether family income at different points in development is differentially associated with these structures. Furthermore, little is known about which environmental factors statistically mediate associations between income and subcortical structure. Using a longitudinal birth cohort and linear mixed-effects models, we identified associations between income-to-needs ratio (INR) at 6 timepoints throughout childhood and hippocampal and amygdala volumes at age 7-9 years (n = 41; 236 INR measurements; 41 brain measurements). Mediation analysis identified environmental sequelae of income that statistically accounted for INR-brain associations. Lower INR prior to age 4 was associated with smaller hippocampal volumes, whereas lower INR prior to age 2 was associated with smaller right amygdala volume. These associations were mediated by unmet basic needs (e.g., food, housing). These findings delineate the temporal specificity of associations between income and hippocampal and amygdala structures.

Risk of lead exposure, subcortical brain structure, and cognition in a large cohort of 9- to 10-year-old children

BACKGROUND

Lead, a toxic metal, affects cognitive development at the lowest measurable concentrations found in children, but little is known about its direct impact on brain development. Recently, we reported widespread decreases in cortical surface area and volume with increased risks of lead exposure, primarily in children of low-income families.

METHODS AND FINDINGS

We examined associations of neighborhood-level risk of lead exposure with cognitive test performance and subcortical brain volumes. We also examined whether subcortical structure mediated associations between lead risk and cognitive performance. Our analyses employed a cross-sectional analysis of baseline data from the observational Adolescent Brain Cognitive Development (ABCD) Study. The multi-center ABCD Study used school-based enrollment to recruit a demographically diverse cohort of almost 11,900 9- and 10-year-old children from an initial 22 study sites. The analyzed sample included data from 8,524 typically developing child participants and their parents or caregivers. The primary outcomes and measures were subcortical brain structure, cognitive performance using the National Institutes of Health Toolbox, and geocoded risk of lead exposure. Children who lived in neighborhoods with greater risks of environmental lead exposure exhibited smaller volumes of the mid-anterior (partial correlation coefficient [rp] = -0.040), central (rp = -0.038), and mid-posterior corpus callosum (rp = -0.035). Smaller volumes of these three callosal regions were associated with poorer performance on cognitive tests measuring language and processing speed. The association of lead exposure risk with cognitive performance was partially mediated through callosal volume, particularly the mid-posterior corpus callosum. In contrast, neighborhood-level indicators of disadvantage were not associated with smaller volumes of these brain structures.

CONCLUSIONS

Environmental factors related to the risk of lead exposure may be associated with certain aspects of cognitive functioning via diminished subcortical brain structure, including the anterior splenium (i.e., mid-posterior corpus callosum).

Mediation Role of Physical Fitness and Its Components on the Association Between Distribution-Related Fat Indicators and Adolescents' Cognitive Performance: Exploring the Influence of School Vulnerability. The Cogni-Action Project

Background: Physical fitness and fatness converge simultaneously modulating cognitive skills, which in turn, are associated with children and adolescents’ socioeconomic background. However, both fitness components and fat mass localization are crucial for understanding its implication at the cognitive level.

Objective: This study aimed to determine the mediation role of a global physical fitness score and its components on the association between different fatness indicators related to fat distribution and adolescents’ cognitive performance, and simultaneously explore the influence of school vulnerability.

Methods: In this study, 1,196 Chilean adolescents participated (aged 10–14; 50.7% boys). Cardiorespiratory fitness (CRF), muscular fitness (MF), and speed-agility fitness (SAF) were evaluated, and a global fitness score (GFS) was computed adjusted for age and sex (CRF + MF + SAF z-scores). Body mass index z-score (BMIz), sum-of-4-skinfolds (4SKF), and waist-to-height ratio (WHtR) were used as non-specific, peripheral, and central adiposity indicators, respectively. A global cognitive score was computed based on eight tasks, and the school vulnerability index (SVI) was registered as high, mid or low. A total of 24 mediation analyses were performed according to two models, adjusted for sex and peak high velocity (Model 1), and adding the school vulnerability index (SVI) in Model 2. The significance level was set at p < 0.05.

Results: The fitness mediation role was different concerning the fatness indicators related to fat distribution analyzed. Even after controlling for SVI, CRF (22%), and SAF (29%), but not MF, mediated the association between BMIz and cognitive performance. Likewise, CRF, SAF and GFS, but not MF, mediated the association between WHtR and cognitive performance (38.6%, 31.9%, and 54.8%, respectively). No mediations were observed for 4SKF.

Conclusion: The negative association between fatness and cognitive performance is mitigated by the level of adolescents’ physical fitness, mainly CRF and SAF. This mediation role seems to be more consistent with a central fat indicator even in the presence of school vulnerability. Strategies promoting physical fitness would reduce the cognitive gap in children and adolescents related to obesity and school vulnerability.

The Association between Body Mass Index and Intra-Cortical Myelin: Findings from the Human Connectome Project

Intra-cortical myelin is a myelinated part of the cerebral cortex that is responsible for the spread and synchronization of neuronal activity in the cortex. Recent animal studies have established a link between obesity and impaired oligodendrocyte maturation vis-à-vis cells that produce and maintain myelin; however, the association between obesity and intra-cortical myelination remains to be established. To investigate the effects of obesity on intra-cortical myelin in living humans, we employed a large, demographically well-characterized sample of healthy young adults drawn from the Human Connectome Project (n = 1066). Intra-cortical myelin was assessed using a novel T1-w/T2-w ratio method. Linear regression analysis was used to investigate the association between body mass index (BMI), an indicator of obesity, and intra-cortical myelination, adjusting for covariates of no interest. We observed BMI was related to lower intra-cortical myelination in regions previously identified to be involved in reward processing (i.e., medial orbitofrontal cortex, rostral anterior cingulate cortex), attention (i.e., visual cortex, inferior/middle temporal gyrus), and salience detection (i.e., insula, supramarginal gyrus) in response to viewing food cues (corrected p < 0.05). In addition, higher BMIs were associated with more intra-cortical myelination in regions associated with somatosensory processing (i.e., the somatosensory network) and inhibitory control (i.e., lateral inferior frontal gyrus, frontal pole). These findings were also replicated after controlling for key potential confounding factors including total intracranial volume, substance use, and fluid intelligence. Findings suggested that altered intra-cortical myelination may represent a novel microstructure-level substrate underlying prior abnormal obesity-related brain neural activity, and lays a foundation for future investigations designed to evaluate how living habits, such as dietary habit and physical activity, affect intra-cortical myelination.

Direct and indirect links between children's socio-economic status and education: pathways via mental health, attitude, and cognition

A child's socio-economic environment can profoundly affect their development. While existing literature focusses on simplified metrics and pair-wise relations between few variables, we aimed to capture complex interrelationships between several relevant domains using a broad assessment of 519 children aged 7-9 years. Our analyses comprised three multivariate techniques that complimented each other, and worked at different levels of granularity. First, an exploratory factor analysis (principal component analysis followed by varimax rotation) revealed that our sample varied along continuous dimensions of cognition, attitude and mental health (from parallel analysis); with potentially emerging dimensions speed and socio-economic status (passed Kaiser's criterion). Second, k-means cluster analysis showed that children did not group into discrete phenotypes. Third, a network analysis on the basis of bootstrapped partial correlations (confirmed by both cross-validated LASSO and multiple comparisons correction of binarised connection probabilities) uncovered how our developmental measures interconnected: educational outcomes (reading and maths fluency) were directly related to cognition (short-term memory, number sense, processing speed, inhibition). By contrast, mental health (anxiety and depression symptoms) and attitudes (conscientiousness, grit, growth mindset) showed indirect relationships with educational outcomes via cognition. Finally, socio-economic factors (neighbourhood deprivation, family affluence) related directly to educational outcomes, cognition, mental health, and even grit. In sum, cognition is a central cog through which mental health and attitude relate to educational outcomes. However, through direct relations with all components of developmental outcomes, socio-economic status acts as a great 'unequaliser'.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12144-021-02232-2.

Gene × Environment Interactions in the Development of Preschool Effortful Control, and Its Implications for Childhood Externalizing Behavior

This study examined the role of gene × environment interaction (G × E) in the development of effortful control (EC) and externalizing symptoms (EXT). Participants included 361 adopted children, and their Adoptive Parents (APs) and Birth Mothers (BMs), drawn from the Early Growth and Development Study. The primary adoptive caregivers' (AP1) laxness and overreactivity were assessed when children were 27-months-old, and used as indices of environmental influences on EC. Heritable influences on child EC were assessed by the BMs' personality characteristics (emotion dysregulation, agreeableness). Secondary adoptive caregivers (AP2) reported on children's EC at 54 months, and EXT at 7 years. Interactions between BM characteristics and AP1 laxness were related to EC and indirectly predicted EXT via EC. Parental laxness and EC were positively associated if children had high heritable risk for poor EC (BM high emotion dysregulation or low agreeableness), but negatively associated if children had low heritable risk for poor EC (BM low emotion dysregulation or high agreeableness). BM agreeableness also moderated associations between AP1 overreactivity and effortful control, and yielded a similar pattern of results. Our findings suggest that G × E is an important first step in the development of EXT via its effect on EC. Consistent with "goodness of fit" models, heritable tendencies can affect which parenting practices best support EC development.

Association of Local Variation in Neighborhood Disadvantage in Metropolitan Areas With Youth Neurocognition and Brain Structure

Importance

Neighborhood disadvantage is an important social determinant of health in childhood and adolescence. Less is known about the association of neighborhood disadvantage with youth neurocognition and brain structure, and particularly whether associations are similar across metropolitan areas and are attributed to local differences in disadvantage.

Objective

To test whether neighborhood disadvantage is associated with youth neurocognitive performance and with global and regional measures of brain structure after adjusting for family socioeconomic status and perceptions of neighborhood characteristics, and to assess whether these associations (1) are pervasive or limited, (2) vary across metropolitan areas, and (3) are attributed to local variation in disadvantage within metropolitan areas.

Design, Setting, and Participants

This cross-sectional study analyzed baseline data from the Adolescent Brain and Cognitive Development (ABCD) Study, a cohort study conducted at 21 sites across the US. Participants were children aged 9.00 to 10.99 years at enrollment. They and their parent or caregiver completed a baseline visit between October 1, 2016, and October 31, 2018.

Exposures

Neighborhood disadvantage factor based on US census tract characteristics.

Main Outcomes and Measures

Neurocognition was measured with the NIH Toolbox Cognition Battery, and T1-weighted magnetic resonance imaging was used to assess whole-brain and regional measures of structure. Linear mixed-effects models examined the association between neighborhood disadvantage and outcomes after adjusting for sociodemographic factors.

Results

Of the 11 875 children in the ABCD Study cohort, 8598 children (72.4%) were included in this analysis. The study sample had a mean (SD) age of 118.8 (7.4) months and included 4526 boys (52.6%). Every 1-unit increase in the neighborhood disadvantage factor was associated with lower performance on 6 of 7 subtests, such as Flanker Inhibitory Control and Attention (unstandardized Β = -0.5; 95% CI, -0.7 to -0.2; false discovery rate (FDR)-corrected P = .001) and List Sorting Working Memory (unstandardized Β = -0.7; 95% CI, -1.0 to -0.3; FDR-corrected P < .001), as well as on all composite measures of neurocognition, such as the Total Cognition Composite (unstandardized Β = -0.7; 95% CI, -0.9 to -0.5; FDR-corrected P < .001). Each 1-unit increase in neighborhood disadvantage was associated with lower whole-brain cortical surface area (unstandardized Β = -692.6 mm2; 95% CI, -1154.9 to -230.4 mm2; FDR-corrected P = .007) and subcortical volume (unstandardized Β = -113.9 mm3; 95% CI, -198.5 to -29.4 mm3; FDR-corrected P = .03) as well as with regional surface area differences, primarily in the frontal, parietal, and temporal lobes. Associations largely remained after adjusting for perceptions of neighborhood safety and were both consistent across metropolitan areas and primarily explained by local variation in each area.

Conclusions and Relevance

This study found that, in the US, local variation in neighborhood disadvantage was associated with lower neurocognitive performance and smaller cortical surface area and subcortical volume in young people. The findings demonstrate that neighborhood disadvantage is an environmental risk factor for neurodevelopmental and population health and enhancing the neighborhood context is a promising approach to improving the health and development of children and adolescents.

Early life socioeconomic status predicts cognition regardless of education level

BACKGROUND AND PURPOSE

Early life socioeconomic status (SES) may impact cognitive performance later in life. We investigated the effect on cognitive performance of early life SES, education, and late life SES in the Brazilian Longitudinal Study of Adult Health.

METHODS

Path analysis was used to decompose associations between SES measures across the lifespan and cognition. The model included direct paths to cognition from early life SES, education, and late life SES, and indirect paths from early life passing through education and late life SES. We investigated whether the effects of early life SES are similar across middle-aged and older adults.

RESULTS

In 13,395 adults, the mean age was 51.5 (8.9) years, 54% were female, 53% were white, and 56% had at least college education. The direct path from early life SES remained significant in the presence of mediation paths through education, late life SES, or both, contributing to cognitive performance in both middle-aged and older adults. The indirect and total effect of early life SES was smaller for middle-aged compared to older adults. Early life SES continues to impact cognitive performance later in life independently of educational attainment and late life SES. The higher percent of mediation through education suggests that education may improve later life cognition even in the presence of low early life SES.

CONCLUSIONS

Our results highlight the importance of public health initiatives to improve early life SES and education to foster cognitive aging in low- and middle-income countries.

Relation of a Socioeconomic Index with Cognitive Function and Neuroimaging in Hypertensive Individuals

BACKGROUND

Socioeconomic factors are important contributors to brain health. However, data from developing countries (where social inequalities are the most prominent) are still scarce, particularly about hypertensive individuals.

OBJECTIVE

To evaluate the relationship between socioeconomic index, cognitive function, and cortical brain volume, as well as determine whether white matter hyperintensities are mediators of the association of the socioeconomic index with cognitive function in hypertensive individuals.

METHODS

We assessed 92 hypertensive participants (mean age = 58±8.6 years, 65.2%female). Cognitive evaluation and neuroimaging were performed and clinical and sociodemographic data were collected using questionnaires. A socioeconomic index was created using education, income, occupation (manual or non-manual work), and race. The associations of the socioeconomic index with cognitive performance and brain volume were investigated using linear regression models adjusted for age, sex, time of hypertension since diagnosis, and comorbidities. A causal mediation analysis was also conducted.

RESULTS

Better socioeconomic status was associated with better visuospatial ability, executive function, and global cognition. We found associations between a better socioeconomic index and a higher parietal lobe volume. White matter hyperintensities were also not mediators in the relationship between the socioeconomic index and cognitive performance.

CONCLUSION

Socioeconomic disadvantages are associated with worse cognitive performance and brain volume in individuals with hypertension.