Face processing in early development: a systematic review of behavioral studies and considerations in times of COVID-19 pandemic

Abstract

Human faces are one of the most prominent stimuli infants in the visual environment of young infants and convey critical information for the development of social cognition. During the COVID-19 pandemic, mask wearing has become a common practice outside the home environment. With masks covering nose and mouth regions, the facial cues available to the infant are impoverished. The impact of these changes on development is unknown, but is critical to debates around mask mandates in early childhood settings. As infants grow, they increasingly interact with a broader range of familiar and unfamiliar people outside the home; in these settings, mask wearing could possibly influence social development. In order to generate hypotheses about the effects of mask wearing on infant social development, in the present work we systematically review N=129 studies selected based on the most recent PRISMA guidelines providing a state-of-the-art framework of behavioural studies investigating face processing in early infancy. We focused on identifying sensitive periods during which being exposed to specific facial features or to the entire face configuration has been found to be important for the development of perceptive and socio-communicative skills. For perceptive skills, infants gradually learn to analyze the eyes or the gaze direction within the context of the entire face configuration. This contributes to identity recognition as well as emotional expression discrimination. For socio-communicative skills, direct gaze and emotional facial expressions are crucial for attention engagement while eye-gaze cuing is important for joint attention. Moreover, attention to the mouth is particularly relevant for speech learning. We discuss possible implications of the exposure to masked faces for developmental needs and functions. Providing groundwork for further research, we encourage the investigation of the consequences of mask-wearing for infants’ perceptive and socio-communicative development, suggesting new directions within the research field.

Face Processing in Early Development: A Systematic Review of Behavioral Studies and Considerations in Times of COVID-19 Pandemic

“…This manuscript has been released as a PrePrint at: https:// psyarxiv.com/rfnj6 (Carnevali et al, 2021).…”

How Infants Learn From a World of Faces: Implications for Racial Biases and Mask-Wearing

“…Consequently, much remains unknown about how the faces that infants see may be leveraged to enrich their learning, or how variations in the availability or nature of facial cues (e.g., widespread use of face-masking veils or masks in public spaces) impact it. For example, while the COVID-19 pandemic necessitates the universal wearing of face masks, surprisingly little is known about how infants process cues from mask-wearing faces (Carnevali et al, 2021; in adults, see, e.g., Barrick et al, 2021). Clear masks or face shields have been proposed as an alternative to opaque masks to facilitate infants' access to visual speech and other facial cues.…”

Early Word Segmentation Behind the Mask

“…In addition, a face mask did not affect adults' performance in a gaze-cuing task (Dalmaso et al, 2021 ). Given the alterations in the visual and/or acoustic speech signal and their impacts on adult speech processing, researchers have also raised the question whether face masks have an impact on speech perception in infants (e.g., Carnevali et al, 2021 ; Lewkowicz, 2021 ; Yeung et al, 2021 ).…”