Maternal contingent responsiveness moderates temperamental risk to support adaptive infant brain and socioemotional development across the first year of life.

In the first few months of life, infants display intriguing individual differences in how they react to novel stimuli in their environment. Infant "negative reactive" tendencies have been robustly linked to resting brain activity profiles that confer risk for maladaptive socioemotional outcomes. The present study examines whether and how caregiver behavior in early infancy may interact with infant negative reactivity to alter the extent to which such tendencies predict risk-related brain activity profiles. In the present study, 51 mothers (all White; age M = 32 years, SD = 3; 70.8% monthly household income > 3,400 U.S. dollars) and their infants (39.2% female at birth) participated. We measured infant negative reactivity and maternal contingent responsiveness to infant's gaze during mother-infant interactions at age 4 months. At 10-11 months, we assessed infants' resting electroencephalographic (EEG) 6-9 Hz frontal asymmetry (a marker of risk for maladaptive regulatory behaviors and withdrawal), infant fearful withdrawal, and infant empathic behavior. We found that maternal contingent responsiveness to 4-month-old infant's gaze in naturalistic interactions moderated the relation between 4-month infant negative reactivity and 11-month resting EEG asymmetry. Results suggest that maternal contingent responsiveness alters the extent to which early reactive tendencies end up "embedded" in infant brain activity profiles. Exploratory analyses revealed that the interaction between maternal contingent responsiveness and infant reactivity predicting infant resting EEG asymmetry, in turn predicted infants' fearful withdrawal and empathic behaviors also assessed at 10-11 months. Findings demonstrate the critical buffering role of maternal contingent responsive behaviors in reducing potential maladaptive neural and socioemotional outcomes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).