The Influence of Neighborhood on Infant Parasympathetic Nervous System Development.

The adaptive calibration model (ACM) asserts that the stress response system, including the parasympathetic nervous system (PNS), conditionally adapts to one's environment. In infancy, the proximal context of parental influences (e.g., maternal depression/anxiety) affects the development of the infant stress response system. In contrast, the relation between broader contexts, such as neighborhood environment, and infant PNS development is less well understood, despite the impact neighborhoods may have on maternal mental health and youth outcomes. The present study bridges prior research examining relations between neighborhood and maternal depression, and maternal depression and infant PNS development. Latent growth curve analysis with mother-infant dyads (N = 320), assessed when infants were 4, 8, 12, 18, and 24 months old, indicated that maternal depressive symptoms showed global decreases across infancy and that infant resting RSA showed global increases, as well as variability across the sample in these trajectories. Moderated mediation modeling showed significant direct effects of neighborhood structural disadvantage on initial levels of infant resting RSA. However, there were no significant indirect effects of neighborhood through maternal depressive symptoms on RSA levels or trajectories. These findings suggest that the broader environment impacts infant stress response system development, but this may occur through other mechanisms beyond proximal maternal depressive symptoms.