Abstract
Maternal odor is known to play an important role in mother-infant-interaction in many altricial species such as rodents. However, we only know very little about its role in early human development. The present study therefore investigated the impact of maternal odor on infant brain responses to threat signals. We recorded the electroencephalographic (EEG) signal of seven-month-old infants watching happy and fearful facial expressions. While infants in two control groups showed the expected EEG fear response, this response was markedly absent in the group exposed to their mother’s odor. Thus, infants respond differently to fear signals in the presence of their mother and the mother’s odor is a sufficiently strong signal to elicit this effect. Our data suggest that olfaction, a sensory modality that has been largely neglected as a social signal in our own species, might function as a crucial modulator in early social learning.