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.

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.

Developmental Changes in the Association Between Cognitive Control and Anxiety.

Anxiety has been associated with reliance on reactive (stimulus-driven/reflexive) control strategies in response to conflict. However, this conclusion rests primarily on indirect evidence. Few studies utilize tasks that dissociate the use of reactive ('just in time') vs. proactive (anticipatory/preparatory) cognitive control strategies in response to conflict, and none examine children diagnosed with anxiety. The current study utilizes the AX-CPT, which dissociates these two types of cognitive control, to examine cognitive control in youth (ages 8-18) with and without an anxiety diagnosis (n = 56). Results illustrate that planful behavior, consistent with using a proactive strategy, varies by both age and anxiety symptoms. Young children (ages 8-12 years) with high anxiety exhibit significantly less planful behavior than similarly-aged children with low anxiety. These findings highlight the importance of considering how maturation influences relations between anxiety and performance on cognitive-control tasks and have implications for understanding the pathophysiology of anxiety in children.

Inhibitory control and set shifting describe different pathways from behavioral inhibition to socially anxious behavior.

Individuals with a behaviorally inhibited (BI) temperament are more likely to develop social anxiety. However, the mechanisms by which socially anxious behavior emerges from BI are unclear. Variation in different forms of top-down control, specifically executive functions (EF), may play distinct roles and characterize differential pathways to social anxiety. Here 291 children were assessed for BI in toddlerhood (ages 2 and 3), parent-reported inhibitory control and set shifting during middle childhood (age 7), and multidimensional assessment of socially anxious behavior completed during late childhood and early adolescence (ages 9 and 12). Structural equation modeling revealed that early variation in BI predicted the development of socially anxious behavior through either higher levels of parent-reported inhibitory control or lower levels of parent-reported set shifting. These data reinforce the notion that top-down control does not uniformly influence relations between temperament and socially anxious behavior. These data suggest novel approaches to thinking about the role of EFs and social anxiety outcomes as children approach adolescence.

The influence of social motivation on neural correlates of cognitive control in girls.

Motivation influences cognitive control, particularly in childhood and adolescence. Previous work finds that the error-related negativity (ERN), an event-related potential (ERP) linked to cognitive control following errors, is influenced by social motivation. However, it is unclear whether the influences of social motivation on the ERN extend to stimulus-locked neural correlates of cognitive control. This study reexamines how social motivation influences cognitive control in adolescence by exploring motivational influences on two stimulus-locked ERPs; the N2 and P3. Adolescent girls (8-17 years of age) completed a flanker task under two different conditions. In the social condition, girls were led to believe that they were evaluated by a peer during a flanker task. In the nonsocial condition, girls completed a flanker task while evaluated by a computer. Results revealed that all girls exhibited a larger P3 in social as compared to nonsocial contexts, whereas the N2 was not different between contexts. In addition, the largest P3 enhancements were observed among younger girls. These findings suggest that social motivation influences some ERP components related to cognitive control, and such influences change across development. Additionally, findings suggest the importance of including multiple ERPs when interpreting the functional significance of motivation on cognitive control.

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.

Changes in working memory influence the transition from reactive to proactive cognitive control during childhood.

Cognitive control develops rapidly over the first decade of life, with one of the dominant changes being a transition from reliance on 'as-needed' control (reactive control) to a more planful, sustained form of control (proactive control). Although the emergence of proactive control is important for mature behavior, we know little about how this transition takes place, the neural correlates of this transition, and whether development of executive functions influences the ability to adopt a proactive control strategy. This study addresses these questions, focusing on the transition from reactive to proactive control in a cross-sectional sample of 79 children-forty-one 5-year-olds and thirty-eight 9-year-olds. Children completed an adapted version of the AX-Continuous Performance Task while electroencephalography was recorded and a standardized executive function battery was administered. Results revealed 5-year-olds predominantly employed reactive strategies, whereas 9-year-olds used proactive strategies. Use of proactive control was predicted by working memory ability, above and beyond other executive functions. Moreover, when enacting proactive control, greater increases in neural activity underlying working memory updating were observed; links between working memory ability and proactive control strategy use were mediated by such neural activity. These results provide convergent evidence that the transition from reactive to proactive control may be dependent on age-related changes in neurocognitive indices of working memory and that working memory may influence adopting a proactive control strategy.

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.

Attention bias to reward predicts behavioral problems and moderates early risk to externalizing and attention problems.

The current study had three goals. First, we replicated recent evidence that suggests a concurrent relation between attention bias to reward and externalizing and attention problems at age 7. Second, we extended these findings by examining the relations between attention and behavioral measures of early exuberance (3 years), early effortful control (4 years), and concurrent effortful control (7 years), as well as later behavioral problems (9 years). Third, we evaluated the role of attention to reward in the longitudinal pathways between early exuberance and early effortful control to predict externalizing and attention problems. Results revealed that attention bias to reward was associated concurrently and longitudinally with behavioral problems. Moreover, greater reward bias was concurrently associated with lower levels of parent-reported effortful control. Finally, attention bias to reward moderated the longitudinal relations between early risk factors for behavioral problems (gender, exuberance, and effortful control) and later externalizing and attention problems, such that these early risk factors were most predictive of behavioral problems for males with a large attention bias to reward. These findings suggest that attention bias to reward may act as a moderator of early risk, aiding the identification of children at the highest risk for later behavioral problems.

Relations between catechol-O-methyltransferase Val158Met genotype and inhibitory control development in childhood.

The Val158Met rs4680 single-nucleotide polymorphism (SNP) at the catechol-O-methyltransferase (COMT) gene, primarily involved in dopamine breakdown within prefrontal cortex, has shown relations with inhibitory control (IC) in both adults and children. However, little is known about how COMT genotype relates to developmental trajectories of IC throughout childhood. Here, our study explored the effects of the COMT genotype (Val/Val, Val/Met, and Met/Met) on IC trajectories between the ages of 5 and 10 years. Children (n = 222) completed a Go/Nogo task at ages 5, 7, and 10; IC was characterized using signal detection theory to examine IC performance (d') and response strategy (RS) (criterion). COMT genotype was not related to initial levels of IC performance and RS at age 5 or change in RS from ages 5 to 10. In contrast, COMT genotype was related to change in IC performance between 5 and 10 years. While Val/Val children did not differ from Val/Met children in development of IC performance, children with the Met/Met genotype exhibited more rapid development of IC performance when compared with Val/Met peers. These results suggest that COMT genotype modulates the development of IC performance in middle childhood.

Adolescent cognitive control, theta oscillations, and social observation.

Theta oscillations (4-8 Hz) provide an organizing principle of cognitive control, allowing goal-directed behavior. In adults, theta power over medial-frontal cortex (MFC) underlies conflict/error monitoring, whereas theta connectivity between MFC and lateral-frontal regions reflects cognitive control recruitment. However, prior work has not separated theta responses that occur before and immediately after a motor response, nor explained how medial-lateral connectivity drives different kinds of control behaviors. Theta's role during adolescence, a developmental window characterized by a motivation-control mismatch also remains unclear. As social observation is known to influence motivation, this might be a particularly important context for studying adolescent theta dynamics. Here, adolescents performed a flanker task alone or under social observation. Focusing first on the nonsocial context, we parsed cognitive control into dissociable subprocesses, illustrating how theta indexes distinct components of cognitive control working together dynamically to produce goal-directed behavior. We separated theta power immediately before/after motor responses, identifying behavioral links to conflict monitoring and error monitoring, respectively. MFC connectivity was separated before/after responses and behaviorally-linked to reactive and proactive control, respectively. Finally, distinct forms of post-error control were dissociated, based on connectivity with rostral/caudal frontal cortex. Social observation was found to exclusively upregulate theta measures indexing post-response error monitoring and proactive control, as opposed to conflict monitoring and reactive control. Linking adolescent cognitive control to theta oscillations provides a bridge between non-invasive recordings in humans and mechanistic studies of neural oscillations in animal models; links to social observation provide insight into the motivation-control interactions that occur during adolescence.

Development of inhibitory control during childhood and its relations to early temperament and later social anxiety: unique insights provided by latent growth modeling and signal detection theory.

BACKGROUND: Children with the temperament of behavioral inhibition (BI) face increased risk for social anxiety. However, not all children with BI develop anxiety symptoms. Inhibitory control (IC) has been suggested as a moderator of the pathway between BI and social anxiety. This study uses longitudinal data to characterize development of IC and tests the hypothesis that IC moderates associations between early BI and later social anxiety symptoms. METHODS: Children completed a Go/Nogo task at ages 5, 7, and 10 years as part of a longitudinal study of BI (measured at 2-3 years) and social anxiety symptoms (measured at 12 years). To assess IC development, response strategy (criterion) and inhibitory performance (d') were characterized using signal detection theory. Latent growth models were used to characterize the development of IC and examine relations among BI, IC parameters, and social anxiety symptoms. RESULTS: IC response strategy did not change between 5 and 10 years of age, whereas IC performance improved over time. BI scores in toddlerhood predicted neither initial levels (intercept) nor changes (slope) in IC response strategy or IC performance. However, between ages 5 and 10, rate of change in IC performance, but not response strategy, moderated relations between BI and later parent-reported social anxiety symptoms. Specifically, greater age-related improvements in IC performance predicted higher levels of social anxiety in high BI children. CONCLUSIONS: IC development in childhood occurs independent of BI levels. However, rapid increases in IC performance moderate risk for social anxiety symptoms in children with BI. Implications for theory and practice are discussed.

Prenatal family income, but not parental education, is associated with resting brain activity in 1-month-old infants.

Childhood socioeconomic disadvantage is associated with disparities in development and health, possibly through adaptations in children's brain function. However, it is not clear how early in development such neural adaptations might emerge. This study examined whether prenatal family socioeconomic status, operationalized as family income and average years of parental education, prospectively predicts individual differences in infant resting electroencephalography (EEG; theta, alpha, beta, and gamma power) at approximately 1 month of age (N = 160). Infants of mothers reporting lower family income showed more lower-frequency (theta) and less higher-frequency (beta and gamma) power. These associations held when adjusting for other prenatal and postnatal experiences, as well as infant demographic and health-related factors. In contrast, parental education was not significantly associated with infant EEG power in any frequency band. These data suggest that lower prenatal family income is associated with developmental differences in brain function that are detectable within the first month of life.

Fostering inclusion in EEG measures of pediatric brain activity.

The past two decades have seen a rapid increase in neuroscientific evidence being used to characterize how contextual, structural, and societal factors shape cognition and school readiness. Measures of functional brain activity are increasingly viewed as markers of child development and biomarkers that could be employed to track the impact of interventions. While electroencephalography (EEG) provides a promising tool to understand educational inequities, traditional EEG data acquisition is commonly limited in some racial and ethnic groups due to hair types and styles. This ultimately constitutes unintentional systemic racism by disproportionately excluding participants from certain racial and ethnic groups from participation and representation in neuroscience research. Here, we provide a comprehensive review of how cultural considerations surrounding hair density, texture, and styling consistently skew samples to be less representative by disproportionately excluding Black and Latinx participants. We also provide recommendations and materials to promote best practices.

Theta activity and cognitive functioning: Integrating evidence from resting-state and task-related developmental electroencephalography (EEG) research.

The theta band is one of the most prominent frequency bands in the electroencephalography (EEG) power spectrum and presents an interesting paradox: while elevated theta power during resting state is linked to lower cognitive abilities in children and adolescents, increased theta power during cognitive tasks is associated with higher cognitive performance. Why does theta power, measured during resting state versus cognitive tasks, show differential correlations with cognitive functioning? This review provides an integrated account of the functional correlates of theta across different contexts. We first present evidence that higher theta power during resting state is correlated with lower executive functioning, attentional abilities, language skills, and IQ. Next, we review research showing that theta power increases during memory, attention, and cognitive control, and that higher theta power during these processes is correlated with better performance. Finally, we discuss potential explanations for the differential correlations between resting/task-related theta and cognitive functioning, and offer suggestions for future research in this area.

Effects of institutional rearing and foster care intervention on error monitoring and externalizing behaviors in adolescence.

Children raised in institutions display deficits in error monitoring and increased psychopathology. Deficits in error monitoring might be a pathway for the emergence of psychopathology in previously institutionalized adolescents. Here we investigate the impact of early psychosocial deprivation and a foster care intervention on error monitoring and its association with internalizing and externalizing behavioral problems in adolescence A modified Flanker task assessed error monitoring in 16-year-old adolescents from the BEIP. The ERN and mid-frontal theta power were computed as indices of neural responses of error monitoring. Adolescents who experienced early institutional rearing and were subsequently placed into foster care showed comparable behavioral (RT, accuracy) and neural (ERN, theta power) measures of error monitoring to their never institutionalized peers; whereas adolescents who received care as usual showed both perturbed behavioral performance and neural responses. Longer duration of institutional care was associated with a reduction in mid-frontal theta power. The results further demonstrated a link between error monitoring as measured by ERN and mid-frontal theta and externalizing-ADHD behavioral problems in adolescents who continued receiving care as usual. The results highlight the long-term positive impact of early foster care placement and perturbations due to prolonged institutional care in neural responses of error monitoring.

Associations between maternal stress and infant resting brain activity among families residing in poverty in the U.S.

Growing evidence suggests that maternal experiences of stress shape children's functional brain activity in the first years of life. Individuals living in poverty are more likely to experience stress from a variety of sources. However, it is unclear how stress is related to resting brain activity among children born into poverty. The present study examines whether infants born into households experiencing poverty show differences in brain activity associated with maternal reports of experiencing stress. The analytic sample comprised 247 mother-infant dyads who completed maternal questionnaires characterizing stress, and for whom recordings of infant resting brain activity were obtained at 1 year of age (M=12.93 months, SD=1.66; 50% female). Mothers (40% Black, non-Hispanic, 40% Hispanic, 12% White, non-Hispanic) who reported higher stress had infants who showed more resting brain activity in the lower end of the frequency spectrum (relative theta power) and less resting brain activity in the middle range of the frequency spectrum (relative alpha power). While statistically detectable at the whole-brain level, follow-up exploratory analyses revealed that these effects were most apparent in electrodes over frontal and parietal regions of the brain. These findings held after adjusting for a variety of potentially confounding variables. Altogether, the present study suggests that, among families experiencing low economic resources, maternal reports of stress are associated with differences in patterns of infant resting brain activity during the first year of life.