PROJECT SUMMARY/ABSTRACT The caregiving environment children experience is the most important modifiable feature for shaping brain development and influencing subsequent mental health. Building from knowledge of infant mental health and developmental neuroscience, this NIMH BRAINS award application is designed to advance our understanding of how children’s experiences with their caregivers during infancy, a developmental period characterized by heightened brain plasticity, influences brain and behavioral development. Specifically, we will use innovative methods to characterize multiple aspects of the early caregiving environment in relation to changes in brain structural and functional connectivity that are believed to contribute to the onset of mental disorders. The application of new tools, coupled with traditional metrics, will improve our measurement of children’s experiences using a child-centered approach (i.e., capturing children’s contact with multiple caregivers). To do this, we will recruit 150 women in pregnancy and, following birth, conduct assessments in children’s daily ecological context at ages 1, 6, 12, and 18 months. This project introduces a wearable device technology that can dynamically, unobtrusively, and continuously measure patterns of physical proximity between children and caregivers, regardless of physical location. In addition to children’s proximity to caregivers, we will obtain ecological assessments of language exposure and observation-based caregiver sensitivity and examine the convergence and divergence among these different ways of capturing children’s experiences (Specific Aim 1). While prior research suggests that greater environmental enrichment leads to lower symptoms of psychopathology, the lack of granularity in measurement (i.e., not capturing the full continuum of relative psychosocial neglect–enrichment) has precluded the ability to characterize the shape of these associations (e.g., linear, nonlinear). We will study children selected to range in experiences along the neglect–enrichment continuum and use repeated neuroimaging of infant brain structural and functional connectivity and repeated behavioral assessments to explore the possible profile of the associations between aspects of the caregiving environment and changes in brain and behavior (Specific Aim 2). Last, we will examine how changes in emotion regulation and emotion reasoning circuitry are associated with signs of emerging psychopathology at age 18 months in order to test whether, when, and how variations in early experience influence risk for psychopathology through changes in emotion-related circuitry (Specific Aim 3). Here, neuroimaging is particularly advantageous as it allows us to examine the maturation of emotion-related networks from birth and, importantly, prior to the onset of detectable mental health difficulties. Achievement of the aims of this proposal is expected to meet NIMH’s objectives to determine the biological and psychol...