On February 20th, Stefania defended her dissertation entitled: “The Caregiver Bias in Face Processing: A Multi-Method Investigation in Infants and Children”.
Abstract: Faces are universally important for a variety of reasons, ranging from identifying individuals to conveying social information. There is now ample evidence that, during the first year of life, facial experience provided to each infant by their social environment shapes the development of face representation, which progressively tunes towards the facial characteristics of the individuals that are more salient to the infant.
Data from parental reports and naturalistic studies indicate that there are typically large discrepancies in the social attributes of faces to which infants are exposed during their first year of life, with the majority of facial experience being with individuals of the same race, gender and age as the primary caregiver. Moreover, researchers have argued that the developmental task of forming attachment relationship with caregiver boosts the discrimination of the primary caregiver from all others, making female own-race faces the most socially and emotionally relevant face category for infants. These discrepancies in the amount of interactions, along with enhanced motivation to attend to individuals with demographic characteristics of the primary caregiver have been linked to the emergence in infancy of a representational bias toward caregiver-like faces. Despite such face bias is well established in infancy, little is known about the face-processing behavior later in development, when changes in both the structure of social environment (e.g., exposure to other adults and peers at the daycare) and developmental task (e.g., learning self-mastery) could influence how children attend and process faces.
In this doctoral dissertation, I will present four studies conducted during my PhD, which were aimed to investigate how the face processing system is influenced by each individual’s social experience and developmental tasks during infancy and early childhood.
Study 1 and Study 2 (Chapter 1) investigated the development of the age bias by exploring the effects of early-acquired facial experience on perceptual recognition and visual exploration strategies used to encode adult and child faces in infants and children. Study 1 explored recognition abilities and scanning patterns of adult and child faces in first-born 10-month-old infants. Study 2 investigated these same aspects in 5-year-old children with different amount of experience with child faces resulting from the absence versus presence of an older sibling in the household. This second study also explored the relation between temperamental traits and individual differences in face processing skills. Overall, results showed that experience acquired early in life with adults directs infants’ face-processing behavior towards a better processing of such face age. Instead, in childhood the exposure to different people along with age-specific developmental tasks even out the encoding of adult and child faces.
Studies 3 and 4 (Chapter 2) were aimed at extending evidence on visual scanning strategies and neural activity in encoding facial race and gender attributes in 3- to 6-year-old children. Study 3 explored with multi-method analyses of eye-tracking data how children process the race and the gender of faces, systematically investigating the interaction between those facial attributes. Study 4 investigated children’s neural categorization of race and gender attributes of faces by comparing steady-state visual-evoked potentials in response to female and male faces from both own- and other-race. The results of these studies extend the existing evidence on how race and gender attributes interplay for defining children’s face-processing behavior and yielded novel insights into neural mechanisms underlying the race and gender biases.
Overall, these studies support the hypothesis that face-processing abilities vary throughout development, reflecting the continuous reorganization of the face perception to changing environmental experiences and developmental tasks.