The impact of a poverty reduction intervention on infant brain activity.

Early childhood poverty is a risk factor for lower school achievement, reduced earnings, and poorer health, and has been associated with differences in brain structure and function. Whether poverty causes differences in neurodevelopment, or is merely associated with factors that cause such differences, remains unclear. Here, we report estimates of the causal impact of a poverty reduction intervention on brain activity in the first year of life. We draw data from a subsample of the Baby's First Years study, which recruited 1,000 diverse low-income mother-infant dyads. Shortly after giving birth, mothers were randomized to receive either a large or nominal monthly unconditional cash gift. Infant brain activity was assessed at approximately 1 y of age in the child's home, using resting electroencephalography (EEG; n = 435). We hypothesized that infants in the high-cash gift group would have greater EEG power in the mid- to high-frequency bands and reduced power in a low-frequency band compared with infants in the low-cash gift group. Indeed, infants in the high-cash gift group showed more power in high-frequency bands. Effect sizes were similar in magnitude to many scalable education interventions, although the significance of estimates varied with the analytic specification. In sum, using a rigorous randomized design, we provide evidence that giving monthly unconditional cash transfers to mothers experiencing poverty in the first year of their children's lives may change infant brain activity. Such changes reflect neuroplasticity and environmental adaptation and display a pattern that has been associated with the development of subsequent cognitive skills.

The effect of the COVID-19 pandemic on infant development and maternal mental health in the first 2 years of life.

We investigated how exogenous variation in exposure to the COVID-19 pandemic during the first year of life is related to infant development, maternal mental health, and perceived stress. Ninety-three socioeconomically diverse pregnant women were recruited before the pandemic to participate in a longitudinal study. Infants ranged in age at the beginning of lockdown (0-9.5 months old), thus experiencing different durations of pandemic exposure across the first year of life. The duration of pandemic exposure was not associated with family demographic characteristics, suggesting it captured exogenous variability. We tested associations between this exogenous variation in pandemic exposure and child and family outcomes. We also examined whether mother-reported disruptive life events were correlated with child and family outcomes. We found no association between duration of pandemic exposure in the first year of life and infant socioemotional problems, infant language development, or maternal mental health and perceived stress symptoms, at 12 or 24 months. However, we found that self-reported exposure to pandemic-related disruptive life events predicted greater maternal depression, anxiety, and perceived stress at 12 months, and greater depression and anxiety at 24 months. Socioeconomic status did not moderate these associations. These findings suggest cautious optimism for infants raised during this period.

Relations among Socioeconomic Status, Perceived Stress, and the Home Language Environment.

While socioeconomic disparities in the home language environment have been well established, the mechanisms explaining these disparities are poorly understood. One plausible mechanism is heightened stress. The current study investigated whether maternal perceived stress was 1) associated with measures of the home language environment, and 2) mediated the relation between socioeconomic disparities and the home language environment. Data from three independent studies were analyzed, which together comprised 322 mother-child dyads. Two studies included mothers and their six- to twelve-month-old infants (N = 227). The third included mothers and their five- to nine-year-old children (N = 95). Mothers reported their educational attainment, income, and stress. Language Environment Analysis (LENA) measured the home language environment. As has been previously reported, socioeconomic disparities were observed in adult words and conversational turns. Stress did not mediate these associations, nor was it associated with adult words or conversational turns. Alternate mechanisms for future exploration are discussed.

Mental health and sleep quality of low-income mothers of one-year-olds during the COVID-19 pandemic.

The COVID-19 pandemic and subsequent social restrictions created an unprecedented context for families raising young children. Although studies have documented detrimental effects of the pandemic on maternal well-being, less is known about how the pandemic specifically impacted low-income mothers. We examined depression, anxiety, and sleep quality among low-income mothers of one-year-olds during the early months of the pandemic using data from the Baby's First Years study. Focusing on the control group (n = 547), we compared mothers interviewed before March 14th, 2020 (n = 342) to mothers interviewed between March 14th and June 30th, 2020 (n = 205) to determine whether the pandemic was associated with differences in mental health and sleep quality. Mothers were recruited from four cities in the United States, and most of the sample identified as Hispanic (42.2%) or Black, non-Hispanic (38.6%). We found that mothers interviewed during the pandemic reported better mental health and sleep quality. While we cannot speak to longer-term impacts of the pandemic, it is possible low-income mothers experienced relief from daily stressors during the initial shelter-in-place orders, which may have led to improvements in well-being. These results have implications for understanding how complex life stressors influence mental health and sleep quality among low-income mothers raising young children.

La pandemia del COVID-19 y las subsecuentes restricciones sociales crearon un contexto sin precedentes para las familias que estaban criando niños pequeños. Aunque los estudios han documentado los efectos perjudiciales de la pandemia sobre el bienestar materno, menos se conoce acerca de cómo la pandemia específicamente tuvo un impacto sobre madres de bajos recursos económicos. Examinamos la depresión, ansiedad y calidad del sueño entre madres de bajos recursos económicos de niños de un año de edad durante los primeros meses de la pandemia usando datos del estudio Primeros Años del Bebé. Enfocándonos en el grupo de control (n = 547), comparamos las madres entrevistadas antes del 14 de marzo de 2020 (n = 342) con madres entrevistadas entre el 14 de marzo y el 30 de junio de 2020 (n = 205) para determinar si la pandemia se asociaba con diferencias en salud mental y calidad del sueño. A las madres se les reclutó en cuatro ciudades de Estados Unidos y la mayor parte del grupo muestra se identificaron como Hispanas (42.2%) o Negras no Hispanas (38.6%). Encontramos que las madres entrevistadas durante la pandemia reportaron mejor salud mental y calidad del sueño. A pesar de que no podemos hablar sobre el impacto a largo plazo de la pandemia, es posible que las madres de bajos recursos económicos experimentaran alivio en los factores diarios de estrés durante el inicial mandato de quedarse en su casa, lo cual pudiera haber llevado a mejoras en el bienestar. Estos resultados tienen implicaciones para comprender cómo los complejos factores de estrés influyen en la salud mental y la calidad del sueño entre madres de bajos recursos económicos que crían a niños pequeños.

La pandémie du COVID-19 et les restrictions sociales qui en ont découlé ont créé un contexte sans précédent pour les familles élevant de jeunes enfants. Bien que des études aient documenté des effets préjudiciables de la pandémie sur le bien-être maternel, on en sait moins sur la manière dont la pandémie a spécifiquement impacté les mères de milieux défavorisés. Nous avons examiné la dépression, l'anxiété, et la qualité du sommeil chez des mères de milieux défavorisés avec un enfant d'un an durant les premiers mois de la pandémie, en utilisant des données de l'étude Baby's First Years. Nous concentrant sur le groupe de contrôle (n = 547), nous avons comparé des mères interviewées avant le 14 mars 2020 (n = 342) à des mères interviewées entre le 14 mars et le 30 juin 2020 (n = 205) afin de déterminer si la pandémie était liée à des différences en santé mentale et en qualité de sommeil. Les mères ont été recrutées dans quatre villes des Etats-Unis et la plupart de l'échantillon s'identifiait comme Hispanique (42,2%) ou Noires, non hispaniques (38,6%). Nous avons trouvé que les mères interviewées Durant la pandémie faisaient état d'une meilleure santé mentale et d'une meilleure qualité de sommeil. Bien que nous ne puissions pas parler des impacts de la pandémie à long terme, il est possible que les mères de milieux défavorisés aient fait l'expérience d'un soulagement des facteurs de stress quotidiens durant la période initiale de confinement, ce qui pourrait avoir mené à des améliorations dans le bien-être. Ces résultats ont des implications pour la compréhension de la manière dont des facteurs de stress complexes influencent la santé mentale et la qualité du sommeil chez les mères de milieux défavorisés élevant de jeunes enfants.

Associations among stress and language and socioemotional development in a low-income sample.

Stress has been linked with children's socioemotional problems and lower language scores, particularly among children raised in socioeconomically disadvantaged circumstances. Much of the work examining the relations among stress, language, and socioemotional functioning have relied on assessments of a single dimension of maternal stress. However, stress can stem from different sources, and people may appraise stressors differently. Taking a dimensional approach, this manuscript characterizes stress in multiple ways: as an overall composite; across the constructs of psychological appraisal vs. environmental stressors; and the independent contributions of a variety assessments. Data are from 548 mother-infant dyads (M = 13.14 months, SD = 2.11) who served as the control group for a poverty reduction clinical trial. Mothers completed questionnaires regarding the different types of stresses they may have experienced, as well as their children's language and socioemotional development. Results indicate that, collectively, higher maternal report of stress is associated with lower reports of children's socioemotional and language development. In addition, maternal psychological appraisals of stress were associated with both socioemotional and language development, whereas reports of environmental stressors were only associated with socioemotional development. Together, these findings suggest that maternal reports of stress are associated with lower maternal report of child development among low-income children.

Unconditional cash transfers and maternal substance use: findings from a randomized control trial of low-income mothers with infants in the U.S.

BACKGROUND: Policy debates over anti-poverty programs are often marked by pernicious stereotypes suggesting that direct cash transfers to people residing in poverty encourage health-risking behaviors such as smoking, drinking, and other substance use. Causal evidence on this issue is limited in the U.S. Given the prominent role of child allowances and other forms of cash assistance in the 2021 American Rescue Plan and proposed Build Back Better legislation, evidence on the extent to which a monthly unconditional cash gift changes substance use patterns among low-income mothers with infants warrants attention, particularly in the context of economic supports that can help improve early environments of children. METHOD: We employ a multi-site, parallel-group, randomized control trial in which 1,000 low-income mothers in the U.S. with newborns were recruited from hospitals shortly after the infant's birth and randomly assigned to receive either a substantial ($333) or a nominal ($20) monthly cash gift during the early years of the infant's life. We estimate the effect of the unconditional cash transfer on self-report measures of maternal substance use (i.e., alcohol, cigarette, or opioid use) and household expenditures on alcohol and cigarettes after one year of cash gifts. RESULTS: The cash gift difference of $313 per month had small and statistically nonsignificant impacts on group differences in maternal reports of substance use and household expenditures on alcohol or cigarettes. Effect sizes ranged between - 0.067 standard deviations and + 0.072 standard deviations. The estimated share of the $313 group difference spent on alcohol and tobacco was less than 1%. CONCLUSIONS: Our randomized control trial of monthly cash gifts to mothers with newborn infants finds that a cash gift difference of $313 per month did not significantly change maternal use of alcohol, cigarettes, or opioids or household expenditures on alcohol or cigarettes. Although the structure of our cash gifts differs somewhat from that of a government-provided child allowance, our null effect findings suggest that unconditional cash transfers aimed at families living in poverty are unlikely to induce large changes in substance use and expenditures by recipients. TRIAL REGISTRATION: Registered on Clinical Trials.gov NCT03593356 in July of 2018.

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.

Socioeconomic factors, stress, hair cortisol, and white matter microstructure in children.

Socioeconomic disadvantage has been linked to increased stress exposure in children and adults. Exposure to stress in childhood has been associated with deleterious effects on cognitive development and well-being throughout the lifespan. Further, exposure to stress has been associated with differences in brain development in children, both in cortical and subcortical gray matter. However, less is known about the associations among socioeconomic disadvantage, stress, and children's white matter development. In this study, we investigated whether socioeconomic disparities would be associated with differences in white matter microstructure in the cingulum bundle, as has been previously reported. We additionally investigated whether any such differences could be explained by differences in stress exposure and/or physiological stress levels. White matter tracts were measured via diffusion tensor imaging in 58 children aged 5-9 years. Results indicated that greater exposure to stressful life events was associated with higher child hair cortisol concentrations. Further, physiological stress, as indexed by hair cortisol concentrations, were associated with higher fractional anisotropy in the cingulum bundle. These results have implications for better understanding how perceived and physiological stress may alter neural development during childhood.

Feasibility of assessing brain activity using mobile, in-home collection of electroencephalography: methods and analysis.

The last decade has seen increased availability of mobile electroencephalography (EEG). These mobile systems enable researchers to conduct data collection "in-context," reducing participant burden and potentially increasing diversity and representation of research samples. Our research team completed in-home data collection from more than 400 twelve-month-old infants from low-income backgrounds using a mobile EEG system. In this paper, we provide methodological and analytic guidance for collecting high-quality, mobile EEG in infants. Specifically, we offer insights and recommendations for equipment selection, data collection, and data analysis, highlighting important considerations for selecting a mobile EEG system. Examples include the size of the recording equipment, electrode type, reference types, and available montages. We also highlight important recommendations surrounding preparing a nonstandardized recording environment for EEG collection, obtaining informed consent from parents, instructions for parents during capping and recording, stimuli and task design, training researchers, and monitoring data as it comes in. Additionally, we provide access to the analysis code and demonstrate the robustness of the data from a recent study using this approach, in which 20 artifact-free epochs achieve good internal consistency reliability. Finally, we provide recommendations and publicly available resources for future studies aiming to collect mobile EEG.

Material hardship, prefrontal cortex-amygdala structure, and internalizing symptoms in children.

Material hardship, or difficulty affording basic resources such as food, housing, utilities, and health care, increases children's risk for internalizing problems. The uncinate fasciculus (UNC) and two of the gray matter regions it connects-the orbitofrontal cortex (OFC) and amygdala-may play important roles in the neural mechanisms underlying these associations. We investigated associations among material hardship, UNC microstructure, OFC and amygdala structure, and internalizing symptoms in children. Participants were 5-9-year-old children (N = 94, 61% female) from socioeconomically diverse families. Parents completed questionnaires assessing material hardship and children's internalizing symptoms. High-resolution, T1-weighted magnetic resonance imaging (n = 51), and diffusion tensor imaging (n = 58) data were acquired. UNC fractional anisotropy (FA), medial OFC surface area, and amygdala gray matter volume were extracted. Greater material hardship was significantly associated with lower UNC FA, smaller amygdala volume, and higher internalizing symptoms in children, after controlling for age, sex, and family income-to-needs ratio. Lower UNC FA significantly mediated the association between material hardship and internalizing symptoms in girls but not boys. These findings are consistent with the notion that material hardship may lead to altered white matter microstructure and gray matter structure in neural networks critical to emotion processing and regulation.

Infants of mothers with higher physiological stress show alterations in brain function.

Chronic stress has been increasingly linked with aberrations in children's behavioral, cognitive, and social development, yet the effect of chronic physiological stress on neural development during the first year of life is largely unknown. The present study aims to link a physiological index of chronic stress (maternal hair cortisol concentration) to maturational differences in infant functional brain development during the first year of life. Participants were 94 mother-infant dyads. To index chronic physiological stress, maternal hair samples were assayed for the previous three months' cortisol output. To examine the development of brain function during the first year of life, six-to-twelve-month-old infants (N = 94) completed a resting electroencephalography (EEG) recording. Infants of mothers with evidence of higher physiological stress showed increased relative low-frequency (theta) power and reduced relative high-frequency (alpha, high-gamma) power, compared to infants of mothers with evidence of low physiological stress. This pattern of findings is consistent with other studies suggesting that early life stress may lead to alterations in patterns of infant brain development. These findings are important given that maturational lags in brain development can be long-lasting and are associated with deficits in cognitive and emotional development. The present research also suggests that reducing maternal physiological stress may be a useful target for future interventions aiming to foster neurodevelopment during the first year of life.

Socioeconomic Disparities in Language Input Are Associated With Children's Language-Related Brain Structure and Reading Skills.

The mechanisms underlying socioeconomic disparities in children's reading skills are not well understood. This study examined associations among socioeconomic background, home linguistic input, brain structure, and reading skills in 5-to-9-year-old children (N = 94). Naturalistic home audio recordings and high-resolution, T1-weighted MRI scans were acquired. Children who experienced more adult-child conversational turns or adult words had greater left perisylvian cortical surface area. Language input mediated the association between parental education and left perisylvian cortical surface area. Language input was indirectly associated with children's reading skills via left perisylvian surface area. Left perisylvian surface area mediated the association between parental education and children's reading skills. Language experience may thus partially explain socioeconomic disparities in language-supporting brain structure and in turn reading skills.

Phonological memory problems are magnified in children from language minority homes when predicting reading disability.

Children from language minority (LM) environments speak a language at home that differs from that at school, are often from socioeconomically disadvantaged backgrounds, and are at risk for reading impairment. We evaluated the main effects and interaction of language status and phonological memory and awareness on reading disorder in 352 children from socioeconomically disadvantaged backgrounds. A significant phonological memory by language status interaction indicated that phonological memory problems were magnified in predicting reading impairment in children from LM versus English dominant (ED) homes. Among children without reading disorder, language minority status was unrelated to phonological processing.

School climate is associated with cortical thickness and executive function in children and adolescents.

A positive school climate has been found to support mental and physical health, academic achievement and social adjustment among youth. However, links between school climate and brain structure have not been investigated to date. In this study, we investigated whether school climate was associated with executive function (EF) and brain structure (cortical thickness and surface area) in children and adolescents. We further examined whether these links varied as a function of socioeconomic background. Participants who ranged from 9 to 18 years of age (N = 108) completed EF tasks and a high-resolution, 3-Tesla, T1-weighted magnetic resonance imaging (MRI) scan. Overall school climate, academic support, and family socioeconomic background were assessed using questionnaires. Higher academic support was associated with greater EF task performance and increased global cortical thickness. Additionally, academic support moderated the association between family income and EF, such that children from lower income families performed similarly to their more advantaged peers on EF tasks in the context of positive academic support. This work is the first to link school climate to brain structure and contributes to the growing body of evidence suggesting that academic support may be an important protective factor in the context of socioeconomic disadvantage.

Parental punitive discipline and children's depressive symptoms: Associations with striatal volume.

Although parental harshness has been consistently linked with increased depressive symptoms in youth, its associations with children's brain structure are not well understood. The striatum has been strongly implicated in depression in adolescents and adults. In this study, we investigated the associations among parental harsh discipline, striatal volume, and depressive symptoms in children. Participants were parents and their 5- to 9-year-old children (63% female; 29% African American; 47% Hispanic/Latino). Parents completed questionnaires about their parenting behaviors and children's depressive symptoms. Children participated in a high-resolution, T1-weighted MRI scan, and volumetric data for the caudate, putamen, and nucleus accumbens were extracted (n = 20 with both parenting and MRI data; n = 48 with both MRI and depressive symptom data). Findings indicated that more frequent parental harsh discipline was significantly associated with smaller dorsal striatal volume (caudate plus putamen). In addition, smaller dorsal striatal volume was significantly associated with increased depressive symptoms in children. These associations remained significant after accounting for child age, sex, whole brain volume, and parental depressive symptoms. These findings suggest that parental harsh discipline may be associated with children's striatal volume, which may in turn be associated with their level of depressive symptoms.

The independent and interacting effects of socioeconomic status and dual-language use on brain structure and cognition.

Family socioeconomic status (SES) is strongly associated with children's cognitive development, and past studies have reported socioeconomic disparities in both neurocognitive skills and brain structure across childhood. In other studies, bilingualism has been associated with cognitive advantages and differences in brain structure across the lifespan. The aim of the current study is to concurrently examine the joint and independent associations between family SES and dual-language use with brain structure and cognitive skills during childhood. A subset of data from the Pediatric Imaging, Neurocognition and Genetics (PING) study was analyzed; propensity score matching established an equal sample (N = 562) of monolinguals and dual-language users with similar socio-demographic characteristics (Mage = 13.5, Range = 3-20 years). When collapsing across all ages, SES was linked to both brain structure and cognitive skills. When examining differences by age group, brain structure was significantly associated with both income and dual-language use during adolescence, but not earlier in childhood. Additionally, in adolescence, a significant interaction between dual-language use and SES was found, with no difference in cortical surface area (SA) between language groups of higher-SES backgrounds but significantly increased SA for dual-language users from lower-SES families compared to SES-matched monolinguals. These results suggest both independent and interacting associations between SES and dual-language use with brain development. To our knowledge, this is the first study to concurrently examine dual-language use and socioeconomic differences in brain structure during childhood and adolescence.

Socioeconomic Status, Amygdala Volume, and Internalizing Symptoms in Children and Adolescents.

The associations among socioeconomic disadvantage, amygdala volume, and internalizing symptoms in children and adolescents are unclear and understudied in the extant literature. In this study, we examined associations between socioeconomic status (SES) and amygdala volume by age across childhood and adolescence to test whether socioeconomic disadvantage would be associated with larger amygdala volume at younger ages but with smaller amygdala volume at older ages. We then examined whether SES and amygdala volume were associated with children's levels of anxiety and depression. Participants were 3- to 21-year-olds from the Pediatric Imaging, Neurocognition, and Genetics study (N = 1,196), which included structural magnetic resonance imaging. A subsample (n = 327; 7-21 years of age) completed self-report measures of anxiety and depression. Lower family income and parental education were significantly associated with smaller amygdala volume in adolescence (13-21 years) but not significantly associated with amygdala volume at younger ages (3-12 years). Lower parental education, but not family income, was significantly associated with higher levels of anxiety and depression, even after accounting for family history of anxiety/depression. Smaller amygdala volume was significantly associated with higher levels of depression, even after accounting for parental education and family history of anxiety/depression. These findings suggest that associations between SES and amygdala structure may vary by age. In addition, smaller amygdala volume may be linked with an increased risk for depression in children and adolescents.

Associations between cortical thickness and neurocognitive skills during childhood vary by family socioeconomic factors.

Studies have reported associations between cortical thickness (CT) and socioeconomic status (SES), as well as between CT and cognitive outcomes. However, findings have been mixed as to whether CT explains links between SES and cognitive performance. In the current study, we hypothesized that this inconsistency may have arisen from the fact that socioeconomic factors (family income and parental education) may moderate the relation between CT and neurocognitive skills. Results indicated that associations between CT and cognitive performance did vary by SES for both language and executive function (EF) abilities. Across all ages, there was a negative correlation between CT and cognitive skills, with thinner cortices associated with higher language and EF scores. Similarly, across all cognitive skills, children from higher-SES homes outperformed their age-matched peers from lower-SES homes. Moderation analyses indicated that the impact of SES was not constant across CT, with SES more strongly predictive of EF skills among children with thicker cortices and more strongly predictive of language skills among children with thinner cortices. This suggests that socioeconomic advantage may in some cases buffer against a neurobiological risk factor for poor performance. These findings suggest that links between brain structure and cognitive processes vary by family socioeconomic circumstance.

Home Environment, But Not Socioeconomic Status, is Linked to Differences in Early Phonetic Perception Ability.

Infants perceptually tune to the phonemes of their native languages in the first year of life, thereby losing the ability to discriminate non-native phonemes. Infants who perceptually tune earlier have been shown to develop stronger language skills later in childhood. We hypothesized that socioeconomic disparities, which have been associated with differences in the quality and quantity of language in the home, would contribute to individual differences in phonetic discrimination. Seventy-five infants were assessed on measures of phonetic discrimination at 9 months, on the quality of the home environment at 15 months, and on language abilities at both ages. Phonetic discrimination did not vary according to socioeconomic status (SES), but was significantly associated with the quality of the home environment. This association persisted when controlling for 9-month expressive language abilities, rendering it less likely that infants with better expressive language skills were simply engendering higher quality home interactions. This suggests that infants from linguistically richer home environments may be more tuned to their native language and therefore less able to discriminate non-native contrasts at 9 months relative to infants whose home environments are less responsive. These findings indicate that home language environments may be more critical than SES in contributing to early language perception, with possible implications for language development more broadly.