Brain-behavior correlations during proposed transitions in the mother-child relationship : an examination of behavior and face-processing in six-month- olds and toddlers

The studies contained in this dissertation were conducted to examine potential connections between neurophysiological measures of face processing and behavioral responses to structured mother-child interactions in two ages that have been implicated as developmental transitions in both the face processing literature and the mother-child attachment literature. Chapter's I and II present data from a study that examined a relationship between 6-month-olds' responses to a series of separations and reunions with the mother and the same infant's event-related potential (ERP) responses to mother and stranger faces. In Chapter I, a composite measure of infant behavior was used as a general index of amount of proximity and interaction seeking behaviors. Chapter II extended this investigation to examine three specific behaviors that have been implicated as highly influential in the development of the mother-child relationship during the first year. Taken together, the results of these two chapters suggest that a general measure of amount of proximity seeking exhibited by infants was associated with larger ERP responses to the stranger's face. However, the specific behaviors examined in Chapter II correlated with the identity of the two faces in unique and specific ways, although distress during separations seemed to be particularly related to neural responses to the mother's face. Chapter III presents data from a study conducted with toddlers (28 to 40 months) using the same paradigm. Potential age-related changes in the neural correlates of processing the two faces were examined in this age range as well, as they have not been found in previous work. The findings presented in Chapter III indicated evidence of age-related change in processing faces in general, as well as the identity of the mother and stranger faces in this age range. In addition, related to the findings in Chapter III, toddler distress behaviors during separation were particularly related to neural responses to the mother's face. These results suggest an important relationship between the changing function of the mother-child relationship for the child and the child's neural responses to the mothe