Me, us, and others: exploring the role of familiarity and emotional expressions in face visual awareness.

Faces play a pivotal role in human interaction, and the rapid processing of face identity and emotional expressions is essential for effective social behaviour. Here, we investigated whether and how face identity and emotional expressions jointly affect face visual awareness. We manipulated three levels of identity (Self, Friend, Stranger) and emotional expressions (Happy, Neutral, Angry) in a Binocular Rivalry (BR) paradigm. Results show that Neutral faces dominated longer visual perception as a function of familiarity (i.e. progressing from Stranger to Friend to Self). Happy emotion led to prioritising faces belonging to the social ingroup (i.e. Self and Friend). In contrast, we did not observe any effect of identity on angry emotion. These findings suggest that the visual system prioritises ingroup faces when they express positive emotional contents, whereas it inhibits such an advantage with negative contents. These data suggest that the interaction between identity and emotional content may already occur at the initial stages of perceptual processing through bottom-up sensory modulation.