Abstract
Face-selective regions in the human ventral stream undergo prolonged development from childhood to adulthood. Children also show protracted development of face perception. However, the neural mechanisms underlying the perceptual development remain unknown. Here, we asked if development is associated with changes in neural sensitivity to face identity, or changes in the overall level of response to faces, or both. Using fMRI, we measured brain responses in ventral face-selective regions (IOG-faces, pFus-faces, and mFus-faces) and two object-selective regions (pFs-objects and LO-objects, as control regions) in children (ages 5-12, N=23) and adults (ages 22-34, N=12), when they viewed adult and child faces, which parametrically varied in the amount of dissimilarity. Since similar faces generate lower responses than dissimilar faces due to fMRI-adaptation, it can be used to study neural sensitivity across age groups. Additionally, a subset of participants (12 children; 11 adults) participated in a behavioral experiment conducted to assess perceptual discriminability of face identity. Our data reveal the following main findings: (1) in both children and adults, responses in ventral face-selective regions linearly increased with face dissimilarity (Fig. 1a), (2) neural sensitivity to face identity increased with age in face- but not object-selective regions (Fig. 1b), (3) the amplitude of responses to faces increased with age in both face- and object-selective regions (Fig. 1c) and (4) perceptual discriminability of face identity was correlated with the neural sensitivity to face identity of face-selective regions (Fig. 1d). Our results suggest that developmental increases in neural sensitivity to face identity in face-selective regions improves perceptual discriminability of faces. These findings significantly advance understanding of neural mechanisms underlying the development of face perception and have important implications for assessing development in neural mechanisms of high-level cortical areas.
Meeting abstract presented at VSS 2017