Plasticity of face processing in infancy

TLDR

Experience shapes perceptual development, as evidenced by improved native speech discrimination and declining foreign speech discrimination between 6 and 10 months, and by Nelson’s suggestion that face‑processing systems are similarly sculpted by exposure to different faces. The study investigates whether exposure to nonnative faces in infants aged 6–9 months can preserve the ability to discriminate monkey faces. The authors expose infants to Barbary macaque faces and assess discrimination performance to test this hypothesis. Results show that early exposure to nonnative faces maintains infants’ monkey‑face discrimination beyond the typical loss at 9 months, underscoring the role of experience in face‑processing development.

Abstract

Experience plays a crucial role for the normal development of many perceptual and cognitive functions, such as speech perception. For example, between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the ability to discriminate among foreign speech sounds declines. However, a recent investigation suggests that some experience with nonnative languages from 9 months of age facilitates the maintenance of this ability at 12 months. Nelson has suggested that the systems underlying face processing may be similarly sculpted by experience with different kinds of faces. In the current investigation, we demonstrate that, in human infants between 6 and 9 months of age, exposure to nonnative faces, in this case, faces of Barbary macaques ( Macaca sylvanus ), facilitates the discrimination of monkey faces, an ability that is otherwise lost around 9 months of age. These data support, and further elucidate, the role of early experience in the development of face processing.