M(other) Nurture: Exploring the Influence of Maternal Care on the Development of Infant Emotion Processing, Regulation, and the Emotional Brain

Abstract

The overarching goal of this dissertation was to examine the link between infant emotional development and the caregiving environment. Study 1 focused on the Face-to-Face Still-Face Paradigm (FFSF), in which in vivo interactions between infants and their caregivers are observed. Person-centered analyses were used in order to identify individual differences in FFSF responding based on positive and negative affect at 3 and 7 months. Four classes were found at both timepoints: Social-Positive Oriented, Classic Still-Face, Self-Comfort Oriented, and Distressed Inconsolable. Although number of profiles and their descriptions remained stable from 3-7 months, the infants in each class changed over time. Maternal engagement differed between the Social-Positive Oriented class and Distressed-Inconsolable class at 7 months. We found a significant relationship between the groups we identified at 7 months and attachment quality at 14 months. Study 2 utilized Functional Near Infrared Spectroscopy (fNIRS) to explore the influence of infant temperament and maternal stress on infant medial prefrontal cortex (mPFC) activation in response to angry, happy, and sad emotion faces. A dimension of infant temperament, negative emotionality, predicted significant brain activation across all emotion face conditions. Mother-infant dysfunctional interaction was associated with an increased brain activation response to happy faces. This study provides additional evidence that both maternal caregiving and infant temperament influence the way an infant’s brain processes emotions, demonstrating the importance of early dyadic interaction and its connection with the novelty hypothesis.