Age‐related face processing bias in infancy: Evidence of perceptual narrowing for adult faces

Abstract

Recent data demonstrate a perceptual processing advantage for adult faces in both adults and young children, suggesting that face representation is shaped by visual experience accumulated with different face-age groups. As for species and race, this age bias may emerge during the first year of life as part of the general process of perceptual narrowing, given the extensive amount of social and perceptual experience accumulated with caregivers and/or other adult individuals. Using infant-controlled habituation and visual-paired comparison at test, two experiments were carried out to examine 3- and 9-month-olds' ability to discriminate within adult and infant faces. Results showed that, when they are provided with adequate time to visually compare the stimuli during test trials (Experiment 2), 3-month-olds exhibit above-chance discrimination of adult and infant faces. Instead, 9-month-olds discriminate adult faces but not infant faces (Experiments 1 and 2). Results provide the first evidence of age-related face processing biases in infancy, and show that by 9 months face representations tune to adult human faces.

An adult face bias in infants that is modulated by face race

“…Given that young infants typically prefer familiar stimuli in the social domain, it was hypothesised that Caucasian 3.5- and 6-month-old infants would attend more to Caucasian adult than Caucasian infant stimuli, since adults represent the most highly familiarised age group in the environment of infants. We also predicted that 3.5- and 6-month-old Caucasian infants would not show an age preference for other-race (Asian) faces, in line with the finding that infant gender preference is restricted to own-race faces (Liu et al, 2015a; Quinn et al, 2008) and the adult face bias is confined to own-race faces in 3-year-olds (Macchi Cassia et al, 2014b). To weaken potential low-level explanations for any preferences detected, stimuli were presented in an inverted orientation in a separate condition.…”

“…Instead, research indicates that adults and children are better at recognizing adult faces than children’s faces unless they have specific experience with the latter category. A recent study indicates that 9-month-olds recognize adult faces better than infant faces, whereas 3-month-olds recognize faces from both age classes equally well (Macchi Cassia, Bulf, Quadrelli, & Proietti, 2014a). Thus, it appears that early in development, perceptual processes become tuned to adult faces because these are the faces which infants experience most frequently.…”

“…Recently, Macchi Cassia, Luo, Pisacane, Li, and Lee (2014b) investigated how race and age experiences combine to influence the ability of 3-year-olds to discriminate within adult and child Caucasian and Asian faces. Caucasian and Chinese children with and without older siblings were tested.…”

Development of category formation for faces differing by age in 9‐ to 12‐month‐olds: An effect of experience with infant faces

“…The former refers to formation of discrete groups composed of similar but discriminable individuals, whereas the latter refers to formation of discrete groups of exemplars that are difficult to discriminate. Regarding discrimination, Macchi Cassia et al (2014) reported that 9-month-olds display a downturn in discrimination of infant faces compared to adult faces. These results imply that infants in the current study engaged in categorization of adult faces and categorical perception of infant faces.…”

“…This differential exposure results in poor discrimination abilities for infant faces compared to adult faces in 9-month-olds (Macchi Cassia, Bulf, Quadrelli, & Proietti, 2014). Infants might thus have a more structured representation of adult faces compared to other-age faces due to experience.…”