Explicit and implicit issues in the developmental cognitive neuroscience of social inequality

Lower Childhood Socioeconomic Status Is Associated with Greater Neural Responses to Ambient Auditory Changes in Adulthood

Humans' early life experience varies by socioeconomic status (SES), raising the question of how this difference is reflected in the adult brain. An important aspect of brain function is the ability to detect salient ambient changes while focusing on a task. Here, we ask whether subjective social status during childhood is reflected by the way young adults' brain detecting changes in irrelevant information. In two studies (total n = 58), we examine electrical brain responses in the frontocentral region to a series of auditory tones, consisting of standard stimuli (80%) and deviant stimuli (20%) interspersed randomly, while participants were engaged in various visual tasks. Both studies showed stronger automatic change detection indexed by MMN in lower SES individuals, regardless of the unattended sound's feature, attended emotional content, or study type. Moreover, we observed a larger MMN in lower-SES participants, although they did not show differences in brain and behavior responses to the attended task. Lower-SES people also did not involuntarily orient more attention to sound changes (i.e., deviant stimuli), as indexed by the P3a. The study indicates that individuals with lower subjective social status may have an increased ability to automatically detect changes in their environment, which may suggest their adaptation to their childhood environments.

The promise and pitfalls of a strength-based approach to child poverty and neurocognitive development: Implications for policy

There has been significant progress in understanding the effects of childhood poverty on neurocognitive development. This progress has captured the attention of policymakers and promoted progressive policy reform. However, the prevailing emphasis on the harms associated with childhood poverty may have inadvertently perpetuated a deficit-based narrative, focused on the presumed shortcomings of children and families in poverty. This focus can have unintended consequences for policy (e.g., overlooking strengths) as well as public discourse (e.g., focusing on individual rather than systemic factors). Here, we join scientists across disciplines in arguing for a more well-rounded, "strength-based" approach, which incorporates the positive and/or adaptive developmental responses to experiences of social disadvantage. Specifically, we first show the value of this approach in understanding normative brain development across diverse human environments. We then highlight its application to educational and social policy, explore pitfalls and ethical considerations, and offer practical solutions to conducting strength-based research responsibly. Our paper re-ignites old and recent calls for a strength-based paradigm shift, with a focus on its application to developmental cognitive neuroscience. We also offer a unique perspective from a new generation of early-career researchers engaged in this work, several of whom themselves have grown up in conditions of poverty. Ultimately, we argue that a balanced strength-based scientific approach will be essential to building more effective policies.

Socioeconomic dissociations in the neural and cognitive bases of reading disorders

Childhood socioeconomic status (SES) strongly predicts disparities in reading development, yet it is unknown whether early environments also moderate the cognitive and neurobiological bases of reading disorders (RD) such as dyslexia, the most prevalent learning disability. SES-diverse 6-9-year-old children (n = 155, half with RD) completed behavioral and functional magnetic resonance imaging (fMRI) tasks engaging phonological and orthographic processing, which revealed corresponding double-dissociations in neurocognitive deficits. At the higher end of the SES spectrum, RD was most strongly explained by differences in phonological skill and corresponding activation in left inferior frontal and temporoparietal regions during phonological processing-widely considered the "core deficit" of RD. However, at the lower end of the SES spectrum, RD was most strongly explained by differences in rapid naming skills and corresponding activation in left temporoparietal and fusiform regions during orthographic processing. Findings indicate that children's early environments systematically moderate the neurocognitive systems underlying RD, which has implications for assessment and treatment approaches to reduce SES disparities in RD outcomes. Further, results suggest that reliance on high-SES convenience samples may mask critical heterogeneity in the foundations of both typical and disordered reading development.

The Influence of Socioeconomic Status (SES) and Processing Speed on the Psychological Adjustment and Wellbeing of Pediatric Brain Tumor Survivors

Simple Summary

Processing speed (PS) is one of the most impaired functions in pediatric brain tumor survivors (PBTSs) and it has been linked to difficulties in their psychological functioning, together with other non-insult-related risk factors, such as socio-economic status (SES). Given the psychological adjustment difficulties observed in PBTS, the aim of the current study was to explore the relationship between SES and psychological functioning, measured with the Child Behavioral Checklist (CBCL) and the Strengths and Difficulties Questionnaire, and considering the contribution of PS as a mediator. The results demonstrated that the influence of SES on the CBCL total index was mediated by PS. Furthermore, PS was found to have a mediating effect on the SES–internalizing problems relationship but not on the SES–externalizing problems relationship. These findings suggest that PS may be a rehabilitation target to prevent psychological distress and should be addressed, especially for PBTSs who live in a disadvantaged situation.

Abstract

(1) Background: The relationship between processing speed (PS) and psychological adjustment in the healthy population is well established, as is that between low socio-economic status (SES) and psychological distress. While PS is one of the most impaired functions in pediatric brain tumor survivors (PBTSs), previous research has demonstrated that low SES may be a predictor of increased psychosocial risk in PBTSs. Given the psychological adjustment difficulties observed in PBTS, in the current study we aimed to explore the relationship between SES and psychological functioning, considering the contribution of PS as a mediator. (2) Methods: demographic and clinical data of 80 children (age range: 4–17 y.o.) were retrospectively collected. Psychological measures were the parent-compiled versions of the Child Behavioral Checklist (CBCL) and the Strengths and Difficulties Questionnaire (SDQ). Mediation analysis models were performed on psychological measures with and without the inclusion of covariates. (3) Results: The influence of SES on the CBCL total index was mediated by PS. Furthermore, PS was found to have a mediating effect on the relationship between SES and internalizing problems but not on the relationship between SES and externalizing problems. (4) Conclusions: The results suggest that PS may be a rehabilitation target for the prevention of psychological distress and should be addressed especially for PBTSs who live in a disadvantaged situation.

A Neuropsychological Profile of Developmental Dyscalculia: The Role of Comorbidity

Developmental dyscalculia (DD) has long been thought to be determined by multiple components. Dyscalculia has high comorbidity with other learning and developmental disabilities, including reading and writing disorders, attention deficits, and problems in visual/spatial skills, short memory, and working memory. This study aims to assess prevalence rates for isolated as well as comorbid DD in a sample of Italian-speaking children. In addition, we studied the neuropsychological profile of children with isolated or combined dyscalculia. We tested 380 children (176 males and 204 females) between the ages of 8.17 and 9.33 years using an extensive battery to determine the neuropsychological profile. The assessment included an arithmetic battery and nonverbal intelligence, short-term memory, reading, and writing tests. The results indicated that children with DD more frequently have a reading disorder and writing disorder. They also have a lower nonverbal intelligence quotient (IQ) and obtain significantly lower scores in short-term memory tests and on a visuospatial skills questionnaire. They also had significantly higher scores (indicative of greater attentional difficulties) in the Conners subscale for attentional problems. Children with DD present different cognitive and neuropsychological profiles.

Intersection between social inequality and emotion regulation on emerging adult cannabis use

Emerging adulthood (EA; ages 18-25) is characterized by socioemotional and neurodevelopmental challenges. Cannabis is a widely used substance among EAs, and hazardous use may increase risk for sustained use patterns and related health consequences. Research shows differential increases in hazardous use by objective as well as subjective measures of social inequality, with more concerning trajectories for youth with greater experiences of social inequality. Learning how to flexibly monitor and modify emotions in proactive ways (i.e., emotion regulation) is a central developmental task navigated during the EA window. Challenges to and with emotion regulation processes can contribute to the emergence of mental health symptoms during EA, including hazardous cannabis use. In this perspective, we highlight emotion dysregulation and social inequality as two critical factors that interact to either buffer against or exacerbate cannabis use during the EA period, noting critical gaps in the literature that merit additional research. We recommend novel methods and longitudinal designs to help clarify how dynamic cognition-emotion interplay predicts trajectories of negative emotional experiences and cannabis use in EA.

How Living in Vulnerable Conditions Undermines Cognitive Development: Evidence from the Pediatric Population of Guatemala

Low-socioeconomic backgrounds represent a risk factor for children’s cognitive development and well-being. Evidence from many studies highlights that cognitive processes may be adversely affected by vulnerable contexts. The aim of this study was to determine if living in vulnerable conditions affects childhood cognitive development. To achieve this, we assessed the performance of a sample of 347 Guatemalan children and adolescents aged from 6 to 17 years (M = 10.8, SD = 3) in a series of 10 neuropsychological tasks recently standardized for the pediatric population of this country. Two-fifths of the sample (41.5%) could be considered to have vulnerable backgrounds, coming from families with low-socioeconomic status or having had a high exposure to violence. As expected, results showed lower scores in language and attention for the vulnerable group. However, contrary to expectations, consistent systematic differences were not found in the executive function tasks. Vulnerable children obtained lower scores in cognitive flexibility compared to the non-vulnerable group, but higher scores in inhibition and problem-solving tasks. These results suggest the importance of developing pediatric standards of cognitive performance that take environmental vulnerable conditions into consideration. These findings, one of the first obtained in the Guatemalan population, also provide relevant information for specific educational interventions and public health policies which will enhance vulnerable children and adolescent cognitive development.

Distinct influence of parental occupation on cortical thickness and surface area in children and adolescents: Relation to self-esteem

Studies of socioeconomic disparities have largely focused on correlating brain measures with either composite measure of socioeconomic status (SES), or its components-family income or parental education, giving little attention to the component of parental occupation. Emerging evidence suggests that parental occupation may be an important and neglected indicator of childhood and adolescent SES compared to absolute measures of material resources or academic attainment because, while related, it may more precisely capture position in social hierarchy and related health outcomes. On the other hand, although cortical thickness and surface area are brain measures with distinct genetic and developmental origins, large-scale neuroimaging studies investigating regional differences in interaction of the composite measure of SES or its components with cortical thickness and surface area are missing. We set out to fill this gap, focusing specifically on the role of parental occupation on cortical thickness and surface area by analyzing magnetic resonance imaging scans from 704 healthy individuals (age = 3-21 years). We observed spatially distributed patterns of (parental occupation × age2 ) interaction with cortical thickness (localized at the left caudal middle frontal, the left inferior parietal and the right superior parietal) and surface area (localized at the left orbitofrontal cortex), indicating independent sources of variability. Further, with decreased cortical thickness, children from families with lower parental occupation exhibited lower self-esteem. Our findings demonstrate distinct influence of parental occupation on cortical thickness and surface area in children and adolescents, potentially reflecting different neurobiological mechanisms by which parental occupation may impact brain development.

Parental Education, Household Income, Race, and Children's Working Memory: Complexity of the Effects

Background. Considerable research has linked social determinants of health (SDoHs) such as race, parental education, and household income to school performance, and these effects may be in part due to working memory. However, a growing literature shows that these effects may be complex: while the effects of parental education may be diminished for Blacks than Whites, household income may explain such effects. Purpose. Considering race as sociological rather than a biological construct (race as a proxy of racism) and built on Minorities' Diminished Returns (MDRs), this study explored complexities of the effects of SDoHs on children's working memory. Methods. We borrowed data from the Adolescent Brain Cognitive Development (ABCD) study. The total sample was 10,418, 9- and 10-year-old children. The independent variables were race, parental education, and household income. The primary outcome was working memory measured by the NIH Toolbox Card Sorting Test. Age, sex, ethnicity, and parental marital status were the covariates. To analyze the data, we used mixed-effect regression models. Results. High parental education and household income were associated with higher and Black race was associated with lower working memory. The association between high parental education but not household income was less pronounced for Black than White children. This differential effect of parental education on working memory was explained by household income. Conclusions. For American children, parental education generates unequal working memory, depending on race. This means parental education loses some of its expected effects for Black families. It also suggests that while White children with highly educated parents have the highest working memory, Black children report lower working memory, regardless of their parental education. This inequality is mainly because of differential income in highly educated White and Black families. This finding has significant public policy and economic implications and suggests we need to do far more than equalizing education to eliminate racial inequalities in children's cognitive outcomes. While there is a need for multilevel policies that reduce the effect of racism and social stratification for middle-class Black families, equalizing income may have more returns than equalizing education.

Socioeconomic Status Inequalities Partially Mediate Racial and Ethnic Differences in Children's Amygdala Volume

BACKGROUND

While race/ethnicity and socioeconomic status (SES) impact brain structures such as the amygdala, less is known on whether or not family SES partially explains why amygdala volume is smaller for racial and ethnic minority groups.

PURPOSE

This study tested the mediating effects of family SES on racial and ethnic differences in right and left amygdala volume.

METHODS

We borrowed the structural Magnetic Resonance Imaging (sMRI) data of the Children Brain Cognitive Development (ABCD) study, a brain imaging investigation of childhood brain development in the US. The total sample was 8977, 9-10-year-old children. The independent variables were race and ethnicity. The primary outcomes were right and left amygdala volume. Age, sex, household size, and marital status were the covariates. Multiple SES indicators such as family income, subjective family SES, parental employment, parental education, and neighborhood income were the mediators. To analyze the data, we used regression models without and with our mediators. Sobel test was used to test if these mediational paths are statistically significant.

RESULTS

Black and Latino children had smaller amygdala sizes than non-Latino White children. The effects of race and ethnicity on amygdala volume were partially mediated by SES indicators, suggesting that one of the many reasons Black and Latino children have smaller volumes of right and left amygdala is their lower SES.

CONCLUSIONS

For American children, lower family and neighborhood SES indicators partially, but not fully, explain smaller amygdala sizes of Black and Latino children compared to non- Latino White children.

Subjective Socioeconomic Status and Children's Amygdala Volume: Minorities' Diminish Returns

Considerable research has suggested that low socioeconomic status (SES) negatively influences brain structure, including but not limited to decreased amygdala volume. Considering race and ethnicity as sociological rather than biological constructs, this study was built on minorities' diminished returns (MDRs) to test if the effects of family SES on the total amygdala volume is weaker for black and Latino children than white and non-Latino children. We borrowed data from the Adolescent Brain Cognitive Development (ABCD) study, a national multi-center brain imaging investigation of childhood brain development in the US. The total sample was 9380 9-10-year-old children. The independent variables were subjective family SES and parental education. The primary outcome was total amygdala volume. High subjective SES and parental education were independently associated with larger total amygdala size. The association between high subjective SES and larger total amygdala volume was less pronounced for black and Latino children than white and non-Latino children. For American children, family SES has unequal effects on amygdala size and function, a pattern that is consistent with MDRs. This result suggests that SES loses some of its expected effects for racial and ethnic minority families.

A neurobehavioral study on the efficacy of price interventions in promoting healthy food choices among low socioeconomic families

Given the healthcare costs associated with obesity (especially in childhood), governments have tried several fiscal and policy interventions such as lowering tax and giving rebates to encourage parents to choose healthier food for their family. The efficacy of such fiscal policies is currently being debated. Here we address this issue by investigating how behavioral and brain-based responses in parents with low socioeconomic status change when rebates and lower taxes are offered on healthy food items. We performed behavioral and brain-based experiments, with the latter employing electroencephalography (EEG) acquired from parents while they shop in a simulated shopping market as well as follow up functional magnetic resonance imaging (fMRI) in the more restricted scanner environment. Behavioral data show that lower tax and rebate on healthy foods increase their purchase significantly compared to baseline. Rebate has a higher effect than lower tax treatment. From the EEG and fMRI experiments, we first show that healthy/unhealthy foods elicit least/maximal reward response in the brain, respectively. Further, by offering lower tax or rebate on healthy food items, the reward signal for such items in the brain is significantly enhanced. Second, we demonstrate that rebate is more effective than lower tax in encouraging consumers to purchase healthy food items, driven in part, by higher reward-related response in the brain for rebate. Third, fiscal interventions decreased the amount of frontal cognitive control required to buy healthy foods despite their lower calorific value as compared to unhealthy foods. Finally, we propose that it is possible to titrate the amount of tax reductions and rebates on healthy food items so that they consistently become more preferable than unhealthy foods.

Impact of an Individualized Cognitive Training Intervention in Preschoolers from Poor Homes

Over the last few decades, different interventions were shown to be effective in changing cognitive performance in preschoolers from poor homes undertaking tasks with executive demands. However, this evidence also showed that not all children included in the intervention groups equally increased their performance levels, which could be related to individual and contextual variability. The present study aimed to explore the impact of a computerized cognitive training intervention with lab-based tasks in preschoolers from Unsatisfied Basic Needs (UBN) homes under the consideration of their baseline performance. In the context of a randomized controlled trial design, different interventions were administered to children according to their baseline performance in a variety of cognitive tasks (i.e., executive attention, inhibitory control, working memory, and planning demands). The results showed different patterns of impact on performance depending on the experimental group, supporting the importance of considering individual and contextual differences in the design of interventions aimed at optimizing executive functions in poverty-impacted sample populations in early stages of development.

Neighborhood Poverty and Amygdala Response to Negative Face

Introduction

Considerable research has established a link between socioeconomic status (SES) and brain function. While studies have shown a link between poverty status and amygdala response to negative stimuli, a paucity of knowledge exists on whether neighborhood poverty is also independently associated with amygdala hyperactive response to negative stimuli.

Purpose

Using functional brain imaging data, this study tested the association between neighborhood SES and the amygdala's response to negative stimuli. Considering race as a sociological rather than a biological construct, we also explored racial heterogeneity in this association between non-Hispanic Black and non-Hispanic White youth.

Methods

We borrowed the functional Magnetic Resonance Imaging (fMRI) data of the Adolescent Brain Cognitive Development (ABCD) study. The sample was 2,490 nine to ten year old non-Hispanic Black and non-Hispanic White adolescents. The independent variable was neighborhood income which was treated as a continuous measure. The primary outcomes were the right and left amygdala response to negative face during an N-Back task. Age, sex, race, marital status, and family SES were the covariates. To analyze the data, we used linear regression models.

Results

Low neighborhood income was independently associated with a higher level of amygdala response to negative face. Similar results were seen for the right and left amygdala. These effects were significant net of race, age, sex, marital status, and family SES. An association between low neighborhood SES and higher left but not right amygdala response to negative face could be observed for non-Hispanic Black youth. No association between neighborhood SES and left or right amygdala response to negative face could be observed for non-Hispanic White youth.

Conclusions

For American youth, particularly non-Hispanic Black youth, living in a poor neighborhood predicts the left amygdala reaction to negative face. This result suggested that Black youth who live in poor neighborhoods are at a high risk of poor emotion regulation. This finding has implications for policy making to reduce inequalities in undesired behavioral and emotional outcomes. Policy solutions to health inequalities should address inequalities in neighborhood SES.

Prefrontal Cortex Response to Threat: Race by Age Variation in 9-10 Year Old Children

BACKGROUND

Considerable research has suggested that race and age are two major determinants of brain development, including but not limited to development of the prefrontal cortex (PFC). Minorities' Diminished Returns (MDRs), however, suggests that race (as a proxy of racism) may interact with various determinants of human and brain development. Minimal knowledge, however, exists on whether age and race also interact on shaping PFC response to threat among American children.

PURPOSE

Using data from a task-based functional brain imaging study and considering race as a sociological rather than a biological construct, we investigated combined effects of race and age on prefrontal cortical (PFC) response to threat. We explored racial heterogeneities in the association between age and PFC response to threat by comparing Black and White children.

METHODS

This study used the task-based functional Magnetic Resonance Imaging (fMRI) data from the Adolescents Brain Cognitive Development (ABCD) study, a national, landmark, multi-center brain imaging investigation of 9-10 years old children in the US. The primary outcomes were mean beta weights of n-back runs measuring PFC response to threating versus neutral face contrast in the following regions of interest (ROIs): left hemisphere-lateral orbito-frontal, left hemisphere -superior-frontal, right hemisphere -caudal middle frontal, and right hemisphere -superior frontal cortex. The independent variable was age. Covariates were sex, ethnicity, family socioeconomic status, and neighborhood socioeconomic status. Race was the focal moderator. To analyze the data, we used linear regression models without and with interactions and SES as covariates.

RESULTS

We included 5,066 9-10 years old children. Age and race did not show direct effects on PFC response to threatening relative to neutral faces. While ethnicity, sex, and socioeconomic status were controlled, age and race showed a systematic interaction on PFC response to threatening relative to neutral faces.

CONCLUSIONS

For American children, race and age do not have direct effects but multiplicative effects on PFC response to threat. The results may be reflective of social inequalities in how Black and White children are socialized and developed. The results are important given the role of the PFC in regulating the limbic system response to threat. Coordinated work of the limbic system and PFC is a core element of children's behavioral and emotional development. Future research is needed on how social stratification and racism shape emotion processing and regulation of American children in response to threat.

Functional and Structural Brain Correlates of Socioeconomic Status

Socioeconomic status (SES) is a multidimensional construct that includes not only measures of material wealth, but also education, social prestige, and neighborhood quality. Socioeconomic correlates between wealth and cognitive functions have been well established in behavioral studies. However, functional and structural brain correlates of SES remain unclear. Here, we sought to uncover the most likely neural regions to be affected by low SES, specifically associated with age. Using effect size–seed-based d Mapping, we compiled studies that examined individuals with low SES and performed functional magnetic resonance imaging and voxel-based morphometry meta-analyses. The results revealed that as from early to late age, individuals exposed to low SES are less likely to have sustained executive network activity yet a greater likelihood to enhanced activity within reward-related regions. A similar activity was shown for gray matter volume across early to older age. These findings provide the first quantitative integration of neuroimaging results pertaining to the neural basis of SES. Hypoactivation of the executive network and hyperactivation of the reward network in low SES individuals may support the scarcity hypothesis and animal models of the effects of early adversity.

Brain lateralization of phonological awareness varies by maternal education

Socioeconomic status (SES) has been shown to influence language skills, with children of lower SES backgrounds performing worse on language assessments compared to their higher SES peers. While there is abundant behavioral research on the effects of SES, whether there are differences in the neural mechanisms used to support language skill is less established. In this study, we examined the relation between maternal education (ME), a component of SES, and neural mechanisms of language. We focused on Kindergarten children, at the beginning of formal reading education, and on a pre-reading skill, phonological awareness-the ability to distinguish or manipulate the sounds of language. We determined ME-related differences in neural activity by examining a skill-matched sample of typically achieving 5-year-old children as they performed a rhyme judgment task. We examined brain lateralization in two language processing regions, the inferior frontal gyrus (IFG) and superior temporal gyrus (STG). In the IFG, lateralization was related to ME but not skill: children with low ME showed bilateral activation compared to children with higher ME who showed leftward lateralization. In the STG, there was a skill by ME interaction on lateralization, such that children with high ME showed a positive relation between rightward lateralization and skill and children with low ME showed a positive relation between leftward lateralization and skill. Thus, we demonstrated ME is related to differences in neural recruitment during language processing, yet this difference in recruitment is not indicative of a deficit in linguistic processing in Kindergarten children.

Community participation factors and poor neurocognitive functioning among persons with schizophrenia

Poor neurocognitive functioning among individuals with schizophrenia is typically conceptualized as resulting from a disease process. The objective of this article is to further expand understanding of poor neurocognition beyond pathogenesis toward a perspective that also incorporates community participation factors. This article focuses on three such factors-sedentary behavior, loneliness, and poverty-that have been demonstrated to be related to neurocognition and are highly prevalent among individuals with schizophrenia. This article provides an overview of the research on each factor and discusses its possible connection to neurocognitive challenges for individuals with schizophrenia. Implications for research, policy, and practice efforts are then proposed to broaden approaches to understanding and addressing neurocognitive challenges in this population. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Reading skill-fractional anisotropy relationships in visuospatial tracts diverge depending on socioeconomic status

Low socioeconomic status (SES) has been repeatedly linked with decreased academic achievement, including lower reading outcomes. Some lower SES children do show skills and scores commensurate with those of their higher SES peers, but whether their abilities stem from the same systems as high SES children or are based on divergent strategies is unknown. We here investigated a potential interactive relationship between SES and real-word reading skill in the white matter in 42 typically developing children. SES was determined based on parental education; reading skill and age were not significantly related to SES. There was a significant neural interaction: Clusters in the bilateral inferior longitudinal fasciculus (ILF), left superior longitudinal fasciculus, and left corticospinal tract demonstrated interactive skill-SES relationships in fractional anisotropy. Follow-up analyses demonstrated that higher SES children showed a positive relationship between fractional anisotropy, reflecting tract coherence, and reading skill in left hemisphere tract clusters, whereas lower SES children showed a positive relationship in the right hemisphere homologues. Broadly, the ILF has been demonstrated to support orthographic skill on the left and more general visuospatial processing on the right, so high reading achievement in lower SES children may rely on supplementary visuospatial processing more than for higher SES readers. This pattern is consistent with previous work reporting low SES children's environments to include less rich verbal experience, which may lead them to disproportionately draw on visuospatial skills for success. Further, these results indicate that group SES differences may be best described by an adaptive, not a deficit, model.

Attending, learning, and socioeconomic disadvantage: developmental cognitive and social neuroscience of resilience and vulnerability

We review current findings associating socioeconomic status (SES), development of neurocognitive functions, and neurobiological pathways. A sizeable interdisciplinary literature was organized through a bifurcated developmental trajectory (BiDeT) framework, an account of the external and internal variables associated with low SES that may lead to difficulties with attention and learning, along with buffers that may protect against negative outcomes. A consistent neurocognitive finding is that low-SES children attend to information nonselectively, and engage in late filtering out of task-irrelevant information. Attentional preferences influence the development of latent inhibition (LI), an aspect of learning that involves reassigning meaningful associations to previously learned but irrelevant stimuli. LI reflects learning processes clarifying the relationship between neurobiological mechanisms related to attention and socioeconomic disadvantage during child development. Notably, changes in both selective attention and typical LI development may occur via the mesocorticolimbic dopamine (MsCL-DA) system. Chaotic environments, social isolation, and deprivation associated with low SES trigger stress responses implicating imbalances in the MsCL-DA and consolidating anxiety traits. BiDeT describes plausible interactions between socioemotional traits and low-SES environments that modify selective attention and LI, predisposing individuals to vulnerability in cognitive development and academic achievement. However, positive role models, parental style, and self-regulation training are proposed as potential promoters of resilience.

Development of selective attention in preschool-age children from lower socioeconomic status backgrounds

Although differences in selective attention skills have been identified in children from lower compared to higher socioeconomic status (SES) backgrounds, little is known about these differences in early childhood, a time of rapid attention development. The current study evaluated the development of neural systems for selective attention in children from lower SES backgrounds. Event-related potentials (ERPs) were acquired from 33 children from lower SES and 14 children from higher SES backgrounds during a dichotic listening task. The lower SES group was followed longitudinally for one year. At age four, the higher SES group exhibited a significant attention effect (larger ERP response to attended compared to unattended condition), an effect not observed in the lower SES group. At age five, the lower SES group exhibited a significant attention effect comparable in overall magnitude to that observed in the 4-year-old higher SES group, but with poorer distractor suppression (larger response to the unattended condition). Together, these findings suggest both a maturational delay and divergent developmental pattern in neural mechanisms for selective attention in young children from lower compared to higher SES backgrounds. Furthermore, these findings highlight the importance of studying neurodevelopment within narrow age ranges and in children from diverse backgrounds.

The application of neuroimaging to social inequity and language disparity: A cautionary examination

In the nascent field of the cognitive neuroscience of socioeconomic status (SES), researchers are using neuroimaging to examine how growing up in poverty affects children's neurocognitive development, particularly their language abilities. In this review we highlight difficulties inherent in the frequent use of reverse inference to interpret SES-related abnormalities in brain regions that support language. While there is growing evidence suggesting that SES moderates children's developing brain structure and function, no studies to date have elucidated explicitly how these neural findings are related to variations in children's language abilities, or precisely what it is about SES that underlies or contributes to these differences. This issue is complicated by the fact that SES is confounded with such linguistic factors as cultural language use, first language, and bilingualism. Thus, SES-associated differences in brain regions that support language may not necessarily indicate differences in neurocognitive abilities. In this review we consider the multidimensionality of SES, discuss studies that have found SES-related differences in structure and function in brain regions that support language, and suggest future directions for studies in the area of cognitive neuroscience of SES that are less reliant on reverse inference.

Critical considerations about the use of poverty measures in the study of cognitive development

Developmental psychology and developmental cognitive neuroscience generated evidence at different levels of analysis about the influences of poverty on neurocognitive development (i.e., molecular, neural activation, cognition, behaviour). In addition, different individual and environmental factors were identified as mediators of such influences. Such a complexity is also illustrated through the many poverty conceptual and operational definitions generated by social, human and health sciences. However, to establish the causal relationships between the different factors of poverty and neurocognitive outcomes is still an issue under construction. Most studies of this area apply classic unidimensional poverty indicators such as income and maternal education. Nonetheless, this approach does not take into adequate consideration the variability of neurocognitive outcomes depending on the type of poverty measures, and the dynamic nature of changes during development. This creates a virtual underestimation of the complexity imposed by the involved mediating mechanisms. The scientific and policy implications of this underestimation include the risk of not adequately addressing children rights and developmental opportunities. This article proposes to explore such scenario, which is necessary for the reconsideration of the criteria used to analyse the influences of poverty on child development in general and neurocognitive development in particular.

Child Poverty and the Promise of Human Capacity: Childhood as a Foundation for Healthy Aging

The effect of child poverty and related early life experiences on adult health outcomes and patterns of aging has become a central focus of child health research and advocacy. In this article a critical review of this proliferating literature and its relevance to child health programs and policy are presented. This literature review focused on evidence of the influence of child poverty on the major contributors to adult morbidity and mortality in the United States, the mechanisms by which these associations operate, and the implications for reforming child health programs and policies. Strong and varied evidence base documents the effect of child poverty and related early life experiences and exposures on the major threats to adult health and healthy aging. Studies using a variety of methodologies, including longitudinal and cross-sectional strategies, have reported significant findings regarding cardiovascular disorders, obesity and diabetes, certain cancers, mental health conditions, osteoporosis and fractures, and possibly dementia. These relationships can operate through alterations in fetal and infant development, stress reactivity and inflammation, the development of adverse health behaviors, the conveyance of child chronic illness into adulthood, and inadequate access to effective interventions in childhood. Although the reviewed studies document meaningful relationships between child poverty and adult outcomes, they also reveal that poverty, experiences, and behaviors in adulthood make important contributions to adult health and aging. There is strong evidence that poverty in childhood contributes significantly to adult health. Changes in the content, financing, and advocacy of current child health programs will be required to address the childhood influences on adult health and disease. Policy reforms that reduce child poverty and mitigate its developmental effects must be integrated into broader initiatives and advocacy that also attend to the health and well-being of adults.

Strengths and weakness of neuroscientific investigations of childhood poverty: future directions

The neuroscientific study of child poverty is a topic that has only recently emerged. In comparison with previous reviews (e.g., Hackman and Farah, 2009; Lipina and Colombo, 2009; Hackman et al., 2010; Raizada and Kishiyama, 2010; Lipina and Posner, 2012), our perspective synthesizes findings, and summarizes both conceptual and methodological contributions, as well as challenges that face current neuroscientific approaches to the study of childhood poverty. The aim of this effort is to identify target areas of study that could potentially help build a basic and applied research agenda for the coming years.

Parental socioeconomic status and the neural basis of arithmetic: differential relations to verbal and visuo-spatial representations

We examined the relation of parental socioeconomic status (SES) to the neural bases of subtraction in school-age children (9- to 12-year-olds). We independently localized brain regions subserving verbal versus visuo-spatial representations to determine whether the parental SES-related differences in children's reliance on these neural representations vary as a function of math skill. At higher SES levels, higher skill was associated with greater recruitment of the left temporal cortex, identified by the verbal localizer. At lower SES levels, higher skill was associated with greater recruitment of right parietal cortex, identified by the visuo-spatial localizer. This suggests that depending on parental SES, children engage different neural systems to solve subtraction problems. Furthermore, SES was related to the activation in the left temporal and frontal cortex during the independent verbal localizer task, but it was not related to activation during the independent visuo-spatial localizer task. Differences in activation during the verbal localizer task in turn were related to differences in activation during the subtraction task in right parietal cortex. The relation was stronger at lower SES levels. This result suggests that SES-related differences in the visuo-spatial regions during subtraction might be based in SES-related verbal differences.

Flavonol-rich dark cocoa significantly decreases plasma endothelin-1 and improves cognition in urban children

Air pollution exposures are linked to systemic inflammation, cardiovascular and respiratory morbidity and mortality, neuroinflammation and neuropathology in young urbanites. In particular, most Mexico City Metropolitan Area (MCMA) children exhibit subtle cognitive deficits, and neuropathology studies show 40% of them exhibiting frontal tau hyperphosphorylation and 51% amyloid-β diffuse plaques (compared to 0% in low pollution control children). We assessed whether a short cocoa intervention can be effective in decreasing plasma endothelin 1 (ET-1) and/or inflammatory mediators in MCMA children. Thirty gram of dark cocoa with 680 mg of total flavonols were given daily for 10.11 ± 3.4 days (range 9–24 days) to 18 children (10.55 years, SD = 1.45; 11F/7M). Key metabolite ratios in frontal white matter and in hippocampus pre and during cocoa intervention were quantified by magnetic resonance spectroscopy. ET-1 significantly decreased after cocoa treatment (p = 0.0002). Fifteen children (83%) showed a marginally significant individual improvement in one or both of the applied simple short memory tasks. Endothelial dysfunction is a key feature of exposure to particulate matter (PM) and decreased endothelin-1 bioavailability is likely useful for brain function in the context of air pollution. Our findings suggest that cocoa interventions may be critical for early implementation of neuroprotection of highly exposed urban children. Multi-domain nutraceutical interventions could limit the risk for endothelial dysfunction, cerebral hypoperfusion, neuroinflammation, cognitive deficits, structural volumetric detrimental brain effects, and the early development of the neuropathological hallmarks of Alzheimer's and Parkinson's diseases.

Frontal EEG/ERP correlates of attentional processes, cortisol and motivational states in adolescents from lower and higher socioeconomic status

Event-related potentials (ERPs) and other electroencephalographic (EEG) evidence show that frontal brain areas of higher and lower socioeconomic status (SES) children are recruited differently during selective attention tasks. We assessed whether multiple variables related to self-regulation (perceived mental effort) emotional states (e.g., anxiety, stress, etc.) and motivational states (e.g., boredom, engagement, etc.) may co-occur or interact with frontal attentional processing probed in two matched-samples of fourteen lower-SES and higher-SES adolescents. ERP and EEG activation were measured during a task probing selective attention to sequences of tones. Pre- and post-task salivary cortisol and self-reported emotional states were also measured. At similar behavioural performance level, the higher-SES group showed a greater ERP differentiation between attended (relevant) and unattended (irrelevant) tones than the lower-SES group. EEG power analysis revealed a cross-over interaction, specifically, lower-SES adolescents showed significantly higher theta power when ignoring rather than attending to tones, whereas, higher-SES adolescents showed the opposite pattern. Significant theta asymmetry differences were also found at midfrontal electrodes indicating left hypo-activity in lower-SES adolescents. The attended vs. unattended difference in right midfrontal theta increased with individual SES rank, and (independently from SES) with lower cortisol task reactivity and higher boredom. Results suggest lower-SES children used additional compensatory resources to monitor/control response inhibition to distracters, perceiving also more mental effort, as compared to higher-SES counterparts. Nevertheless, stress, boredom and other task-related perceived states were unrelated to SES. Ruling out presumed confounds, this study confirms the midfrontal mechanisms responsible for the SES effects on selective attention reported previously and here reflect genuine cognitive differences.