Summary of Funded Parent Award and Proposed Supplement Childhood socioeconomic status (SES) is associated with disparities in cognitive, linguistic, and academic development.1,2 Understanding the precise environmental and neurodevelopmental mechanisms that underlie these disparities is critical for developing maximally impactful interventions to reduce and ultimately ameliorate achievement gaps. The parent award proposes and tests an innovative developmental model in which specific features of children’s early language input engage the cascading development of frontotemporal neural networks that ultimately scaffold multiple aspects of social-cognitive development. Beyond just language abilities, these also include executive functioning (EF) and social cognition (SC)— critical school readiness skills that are known to contribute to SES achievement gaps in school.3,4 The parent award investigates three dimensions of language input quality: linguistic (e.g., semantics and syntax), social-interactive (e.g., contingent turn-taking), and conceptual (e.g., decontextualized language) features.5 Investigating these three dimensions in parallel is necessary to understand which aspects of input scaffold various domains of neurocognitive development and in what way. Notably, this research leverages multi-modal assessments of children’s environments (real-world auditory language exposure and lab-based video-coding of parent-child interaction) and brain development (MRI measures of structural brain development and fNIRS measures of brain function during domain-specific cognitive tasks) longitudinally across the preschool years (ages 3;0-4;11 years) to address three specific aims: ● Aim 1: Characterize how three dimensions of early language experience (linguistic, social/interactive, and conceptual) influence structural and functional brain development underlying receptive and expressive language development. ● Aim 2: Evaluate whether specific features of language input serve as a mechanism of SES disparities in nonlinguistic cognitive domains (EF and SC) that are critical for school readiness, either directly or indirectly, through developing language skills. ● Aim 3: Examine whether input-driven, longitudinal development of frontotemporal language-related brain networks also scaffold the development of neural systems underlying the emergence of executive functioning and social cognition. Impact: Results from the parent grant have the potential to identify maximally impactful, malleable intervention targets to help ameliorate income-related achievement gaps in school readiness skills.

Project Narrative The proposed supplement will support postdoc Alexus Ramirez, a promising Latinx early career scholar, through an integrated research and training plan. Alexus’s work will expand upon Aim 2 of the parent award (while remaining within the scope of the parent grant) in two ways: (1) by investigating contextual factors that may moderate the effects of language input mechanisms, and (2) by investigating parental beliefs/attitudes that lead to variation in language input dimensions, both in the original sample plus an additional subsample of n=50 Latinx, Spanish-English dual-language families. Supplemental aims will reveal how the developmental mechanisms explored in the parent grant may vary across developmental contexts, while also providing Alexus Ramirez with critical training in intellectual concepts, methods, community-engaged approaches, grant writing, and other career-relevant skills to launch her independent career and ultimately increase diversity in health-related research.