Is Face Processing Species-Specific During the First Year of Life?

TLDR

Infants between 6 and 10 months improve discrimination of native speech sounds while their ability to discriminate foreign speech sounds declines. The study sought to determine whether perceptual narrowing extends beyond language to face processing. Discrimination of human and monkey faces was assessed in 6‑month‑old infants, 9‑month‑old infants, and adults using a visual paired‑comparison procedure. Only 6‑month‑olds discriminated between human and monkey faces, whereas 9‑month‑olds and adults discriminated only within species, indicating that perceptual narrowing may reflect a broader shift in early cognitive neural networks.

Abstract

Between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the same ability to discriminate among foreign speech sounds decreases. Our study aimed to determine whether this perceptual narrowing is unique to language or might also apply to face processing. We tested discrimination of human and monkey faces by 6-month-olds, 9-month-olds, and adults, using the visual paired-comparison procedure. Only the youngest group showed discrimination between individuals of both species; older infants and adults only showed evidence of discrimination of their own species. These results suggest that the “perceptual narrowing” phenomenon may represent a more general change in neural networks involved in early cognition.