ABSTRACTAdults perceive emotional expressions categorically, with discrimination being faster and more accurate between expressions from different emotion categories than between two stimuli from the same category. The current study sought to test whether facial expressions of happiness and fear are perceived categorically by pre-verbal infants, using a new stimulus set that was shown to yield categorical perception in adult observers. These stimuli were then used with 7-month-old infants using a habituation and visual preference paradigm. Infants were first habituated to an (...) expression of one emotion, then presented with the same expression paired with a novel expression either from the same emotion category or from a different emotion category. After habituation to fear, infants displayed a novelty preference for pairs of between-category expressions, but n... (shrink)

Infants acquire their first words through interactions with social partners. In the first year of life, infants receive a high frequency of visual and auditory input from faces, making faces a potential strong social cue in facilitating word-to-world mappings. In this position paper, we review how and when infant gaze to faces is likely to support their subsequent vocabulary outcomes. We assess the relevance of infant gaze to faces selectively, in three domains: infant gaze to different features within a face (...) ; then to faces ; and finally to more socially relevant types of faces. We argue that infant gaze to faces could scaffold vocabulary construction, but its relevance may be impacted by the developmental level of the infant and the type of task with which they are presented. Gaze to faces proves relevant to vocabulary, as gazes to eyes could inform about the communicative nature of the situation or about the labeled object, while gazes to the mouth could improve word processing, all of which are key cues to highlighting word-to-world pairings. We also discover gaps in the literature regarding how infants’ gazes to faces or to different types of faces relate to vocabulary outcomes. An important direction for future research will be to fill these gaps to better understand the social factors that influence infant vocabulary outcomes. (shrink)