The impact of maternal odor on face processing across infancy

Humans are a social species and already newborns are equipped with a range of abilities that enable them to interact with other human beings around them. These abilities have been investigated extensively in the visual and auditory domain. Other sensory modalities however have been largely neglected. This is in stark contrast to research in other species, which has shown that especially social odor plays a fundamental role in early social development. Only in the past decade, first studies have started to explore the role of maternal odor for sociocognitive processes in early human development, demonstrating an influence on face processing in general and on the processing of facial emotion and identity. At the same time, these initial studies raise a number of questions, in particular with respect to (a) potential developmental changes across the first year of life and (b) the specificity of the reported effect of maternal odor. The present project will fill this gap in our knowledge by systematically investigating the influence of maternal odor across the first year of life. In particular, we will address the following questions: (1) How does the impact of maternal odor on face processing change between 4 and 12 months of age? (2) Which processes does maternal odor influence on a neural, peripheral physiological, and behavioral level and how do they relate to each other? (3) How specific are the reported effects to maternal odor, or can similar effects be observed for other types of familiar social odor (e.g., the father’s odor) or other signals of maternal presence (e.g., touch)? Our primary measure will be electroencephalographic (EEG) recordings, complemented by the analysis of looking behavior, pupil dilation, as well as changes in skin conductance and salivary cortisol level. Answering these questions will not only fill a crucial gap in our understanding of early social development. It will also have implications for future clinical approaches, including interventions targeting children at risk for developing autism spectrum disorder and parent-infant-interaction in families affected by postpartum depression.