Project Summary/Abstract Symptoms of maternal postpartum depression are common, particularly for Black mothers who may face increased risk during the perinatal period. Previous work has demonstrated that postpartum depression can have significant ramifications not only for maternal wellbeing but for infants’ regulatory development. Maternal depression may influence mother-infant coregulatory interactions, or how mothers and infants reciprocally influence one another’s affect, emotion, and physiology. In particular, the parent-child coregulation of physiological activity (i.e., physiological synchrony or the matching of biological states) is a critical process in the development of children’s self-regulation. Physiological synchrony between parents and infants may be a mechanism through which postpartum depression undermines infants’ emerging regulatory capacities. The current proposal aims to (i) determine the consequences of maternal postpartum depressive symptoms for mother-infant physiological synchrony and infant regulatory capacity, (ii) evaluate the role of mother-infant physiological synchrony in shaping infant regulatory capacity, and (iii) evaluate the moderating role of culturally salient risk and resiliency factors (i.e., racial discrimination and collective coping) in shaping physiological synchrony and infant regulatory capacity. To address these aims, the proposed study will draw a subset of data (N = 120) from a larger, prospective longitudinal study of Black mother-infant dyads (N = 350). Maternal self-report of collective coping will be measured in the third trimester. Maternal self-reports of depression and racial discrimination experiences, as well as mother-infant physiological data, will be collected at 6 months infant age. Observational measures of infant regulatory capacity will be collected at 12 months infant age. Postpartum depressive symptoms are hypothesized to predict lower mother-infant physiological synchrony and infant regulatory capacity. Decreased synchrony is also expected to predict lower infant regulatory capacity. Discrimination is expected to increase risk for low physiological synchrony and low infant regulatory capacity in the context of maternal depression, while the use of collective coping strategies is expected to mitigate risk. The results of this study will help to delineate the developmental sequela of postpartum depression for Black mothers and infants and identify relevant risk and protective factors that may serve as important targets for intervention. This research will also contribute to understandings of the intergenerational transmission of racial health disparities and help to leverage parent-child relationships as a buffer against psychosocial stress in Black families. The conceptual, quantitative, and professional training opportunities outlined in the fellowship training plan, in addition to collaboration with renowned experts in psychophysiology, statistical analysis, and cultural proces...