Odors shape the early development of face perception: EEG signatures in the infant brain – ODORINFACE

Human infants need to apprehend much novel sensory information to rapidly engage in adaptive social communication and develop efficient social cognition. In particular, making sense of others’ faces is a challenging task for the immature infant visual system that requires experience to reach full achievement. In this context, olfaction is a functional sensory modality that conveys prior knowledge about conspecifics able to constrain the interpretation of ambiguous visual inputs. Moreover, odors are temporally and spatially stable cues that may improve the generalization of more variable face exemplars into a single category. Accordingly, the main hypothesis of the ODORINFACE project is that experience brought by olfaction during early social interactions is decisive to shape the development of face perception. Based on a pilot study showing that maternal odor enhances a face-selective response in the 4-month-old infant brain, the project will delineate the mechanisms subtending odor-driven early tuning of face perception. To meet this objective, ODORINFACE will isolate and quantify electroencephalographic (EEG) signatures of face perception in each individual infant by means of a frequency-tagging approach.
Four working tasks will precisely investigate the contribution of 4 mechanisms according to 4 principles of multisensory integration: TASK 1 will determine which odor cues in maternal odor help perceive faces (intersensory redundancy); TASK 2 will evaluate whether infants’ early olfactory experience modulates face perception (developmental timing); TASK 3 will explore whether odors facilitate the perception of visual inputs as faces by improving face categorization processes (disambiguation); TASK 4 will determine the decline of the maternal odor effect over the progressive maturation of the face perception system (inverse effectiveness).
ODORINFACE represents an innovative project of high feasibility which responds to basic issues on the early multisensory development of face perception in the light of a generally neglected sensory modality (i.e., olfaction). It uses an original methodological approach (i.e., frequency-tagging) to quantify EEG markers of face perception in the infant brain. Overall, this project offers new perspectives to understand and evaluate a critical function of the early social development that will undoubtedly provide numerous outcomes at both scientific and socioeconomic/societal levels, especially for clinical practices dealing with (a)typical social-cognitive development.