THE DEVELOPMENT OF COGNITIVE CONTROL DURING CHILDHOOD: A NEUROCOGNITIVE PERSPECTIVE

One of the hallmarks of human cognition is its adaptability and ability to prioritize task demands in order to complete a goal – a concept known as cognitive control. Research has shown that cognitive control develops rapidly over the first decade of life. One of the key control-related developments during childhood is the transition from a heavy reliance on in-the-moment and as-needed control recruitment (known as reactive control) to more planful and sustained control (known as proactive control). This transition has been observed in a small number of studies, but much is still unknown about how this transition takes place, the mechanisms support this change, and whether this change is driven by coincident development of executive functions. This dissertation examined the development of cognitive control using a cross-sectional design in 79 children – 41 5-year-olds and 38 9-year-olds. To assess cognitive control strategy use, children completed an adapted version of the AX-Continuous Performance Task (AX-CPT) while we recorded electroencephalography (EEG). Children also completed a standardized executive function battery. Results revealed that 5-year-olds relied on reactive cognitive control strategies, while 9-year-olds relied on proactive cognitive control strategies. These behavioral patterns were associated with differential patterns of neural activation in a component known as the P3b. Executive functions were differentially associated with cognitive control strategy use. Specifically, better working memory and inhibitory control skills were related to proactive strategy use and increased context sensitivity. This study is the first to examine behavioral and neural measures of cognitive control strategy use on an AX-CPT task as well as the unique relations between cognitive control strategy and executive functioning

Co-Rooming Accounts for Socioeconomic Disparities in Infant Sleep Quality among Families Living in Urban Environments

Poor infant sleep quality is associated with negative maternal and infant health outcomes. This study measures socioeconomic disparities in infant sleep quality, and assesses whether child sleep location and maternal stress mediate associations between socioeconomic status (SES) and infant sleep quality. The study includes 86 socioeconomically diverse, mother-infant dyads living in an urban area with infants aged 6–12 months. Mothers reported socioeconomic demographics, infant sleep quality (Brief Infant Sleep Questionnaire) and maternal subjective stress (Perceived Stress Scale). Maternal objective stress was measured via hair cortisol concentration (HCC). The associations among SES, infant sleep quality, infant co-rooming, and maternal stress were assessed. Infants from families with lower income-to-needs (ITN) ratios had poorer infant sleep quality. The association between familial ITN and infant sleep quality was mediated by whether the child co-rooms with parents. Maternal perceived stress was independently associated with infant sleep quality, but HCC was not associated with infant sleep quality

Psychosocial Deprivation, Executive Functions, and the Emergence of Socio-Emotional Behavior Problems

Early psychosocial deprivation can negatively impact the development of executive functions (EFs). Here we explore the impact of early psychosocial deprivation on behavioral and physiological measures (i.e., event-related potentials; ERPs) of two facets of EF, inhibitory control and response monitoring, and their associations with internalizing and externalizing outcomes in the Bucharest Early Intervention Project (BEIP; Zeanah et al., 2003). This project focuses on two groups of children placed in institutions shortly after birth and then randomly assigned in infancy to either a foster care intervention or to remain in their current institutional setting. A group of community controls was recruited for comparison. The current study assesses these children at 8-years of age examining the effects of early adversity, the potential effects of the intervention on EF and the role of EF skills in socio-emotional outcomes. Results reveal exposure to early psychosocial deprivation was associated with impaired inhibitory control on a flanker task. Children in the foster care intervention exhibited better response monitoring compared to children who remained in the institution on the error-related positivity (Pe). Moreover, among children in the foster care intervention those who exhibited larger error-related negativity (ERN) responses had lower levels of socio-emotional behavior problems. Overall, these data identify specific aspects of EF that contribute to adaptive and maladaptive socio-emotional outcomes among children experiencing early psychosocial deprivation

Infants’ experience-dependent processing of male and female faces: Insights from eye tracking and event-related potentials

The goal of the present study was to investigate infants' processing of female and male faces. We used an event-related potential (ERP) priming task, as well as a visual-paired comparison (VPC) eye tracking task to explore how 7-month-old "female expert" infants differed in their responses to faces of different genders. Female faces elicited larger N290 amplitudes than male faces. Furthermore, infants showed a priming effect for female faces only, whereby the N290 was significantly more negative for novel females compared to primed female faces. The VPC experiment was designed to test whether infants could reliably discriminate between two female and two male faces. Analyses showed that infants were able to differentiate faces of both genders. The results of the present study suggest that 7-month olds with a large amount of female face experience show a processing advantage for forming a neural representation of female faces, compared to male faces. However, the enhanced neural sensitivity to the repetition of female faces is not due to the infants' inability to discriminate male faces. Instead, the combination of results from the two tasks suggests that the differential processing for female faces may be a signature of expert-level processing

The beneficial effects of a positive attention bias amongst children with a history of psychosocial deprivation

Children raised in institutions experience psychosocial deprivation that has detrimental influences on attention and mental health. The current study examined patterns of attention biases in children from institutions who were randomized at approximately 21.6 months to receive either a high-quality foster care intervention or care-as-usual. At age 12, children performed a dot-probe task and indices of attention bias were calculated. Additionally, children completed a social stress paradigm and cortisol reactivity was computed. Children randomized into foster care (N=40) exhibited an attention bias toward positive stimuli but not threat, whereas children who received care-as-usual (N=40) and a never-institutionalized comparison group (N=47) showed no bias. Stability of foster care placement was related to positive bias, while instability of foster care placement was related to threat bias. The magnitude of the positive bias was associated with fewer internalizing problems and better coping mechanisms. Within the foster care group, positive attention bias was related to less blunted cortisol reactivity

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

Changes in working memory facilitate 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). While the emergence of proactive control is important for adaptive, mature behavior, we know little about how this transition takes place, the neural correlates of this transition, and whether development of executive functions are a precondition for developing the ability to adopt a proactive control strategy. The present 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, while 9-year-olds used proactive strategies. Critically, 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. Collectively, the results provide convergent evidence that the developmental transition from reactive to proactive control is dependent on neurocognitive development of specific executive functioning skills. Developments in working memory appear to be a precondition for adopting the more mature, and adaptive, proactive control strategy

Higher Utilization of Social Services Is Associated with Higher Language Scores in Children from Deeply Impoverished Urban Families

Language development has been consistently linked with socioeconomic status (SES), with children from lower SES backgrounds at higher risk for language delays. The objective of this study is to investigate the relationship between familial social service use and language development during the first year of life. Thirty-one low-income mothers and their infants were recruited from the New York metropolitan area. Mothers provided information about demographics and utilization of social services (Women, Infants, and Children (WIC), food stamps, Medicaid, and public housing). Infant language skills were assessed using the Preschool Language Scale. Multiple linear regressions were used to investigate the relationship between social service use and language skills. We found that the number of social services utilized was not an overall significant linear predictor of language skills. However, social service use interacted with poverty level to predict language skills. Specifically, for families living in deep poverty, higher service use significantly predicted higher infant language scores (β = 3.4, p = 0.005). These results suggest that social services may be an appropriate target to help narrow socioeconomic disparities in language development