7.7: Characterizing Brain Development from Infancy through Young Adulthood
Adversity, especially early in childhood, has long-lasting consequences on brain development and behavioral outcomes. For instance, research has shown that experiencing poverty during early childhood is associated with lower academic performance, educational attainment, and adult earnings (Duncan et al., 1998, 2010). Relatedly, children whose families have higher family income tend to be associated with higher language, memory, social-emotional processing, and self-regulation skills (Noble et al., 2005, 2007). In terms of the brain, higher family income correlates with expanded surface area in brain regions governing language and executive function (Noble et al., 2015). While poverty clearly correlates with negative brain and behavioral outcomes, much remains unknown about how these effects on neural development emerge over time.
The Baby’s First Years project is conducting the first randomized control trial of poverty reduction in early childhood, examining its impact on brain development (Noble et al., 2021). In the study, 1,000 diverse low-income mothers in four metropolitan areas in the United States were randomly assigned to receive a large ($333) or nominal ($20) monthly cash gift. By measuring infants’ electrical brain activity one year into the poverty-reduction intervention, the researchers showed that infants whose mothers were randomized at the time of birth to receive a large monthly cash gift showed greater electrical brain activity in regions associated with better language, cognitive, and social-emotional outcomes in later childhood. Scientists are continuing to explore how adversity affects brain organization and its potential impact on behavior.
Given the extensive social, emotional, and cognitive changes during adolescence, the Adolescent Brain Cognitive Development (ABCD) study was launched as the largest long-term study of brain development and child health in the United States. Twenty-one U.S. research sites are tracking over 11,000 children’s biological and behavioral development over a decade from age nine through early adulthood (Luciana et al., 2018). The ABCD study assesses brain structure and function, cognition, physical and mental health, social and emotional function, and culture and environment, offering insights into adolescent brain development and its behavioral impacts. The ABCD study’s extensive data explores key topics, such as links between family environment, children’s behavior problems, and brain structure (Gong et al., 2021), effects of cannabis use on psychopathology (Paul et al., 2021), and links between screen time, academic performance, and mental health (Paulich et al., 2021).
These ongoing large-scale studies promise to provide insights into how environmental factors shape brain development and behavior, potentially informing future interventions and policies to support healthy child and adolescent development.
