Abstract
How does the FFA arise in development, and why does it develop so systematically in the same location across individuals? Preferential fMRI responses to faces arise early, by around 6 months of age in humans (Deen et al., 2017). Arcaro et al (2017) have further shown that monkeys reared without ever seeing a face show no face-selective patches, and regions that later become face selective are correlated in resting fMRI with foveal retinotopic cortex in newborn monkeys. These findings have been taken to argue that 1) seeing faces is necessary for the development of face-selective patches and 2) face patches arise in previously fovea-biased cortex because early experience with faces is foveally biased. Here we present evidence against both these claims. We scanned congenitally blind subjects (N = 6) with fMRI while they performed a one-back haptic shape discrimination task, sequentially palpating 3D-printed photorealistic models of faces, hands, mazes and chairs in a blocked design. Five out of six participants showed significantly higher responses to faces than other categories in the lateral fusiform gyrus (see Figure 1 A,B). Overall, the face selectivity of fusiform regions for tactile faces in congenitally blind participants was comparable to the face selectivity in sighted subjects (N = 8) for videos of the same stimuli rotating in depth (see Figure1 C,D). Evidently, the development of strongly face-selective responses in the lateral fusiform gyrus does not require a) seeing faces, b) foveating faces, or c) perceptual expertise with faces. We speculate that face selectivity in congenitally blind participants reflects either amodal representations of shape and/or the interpretation of faces as social stimuli (Van den Hurk et al, 2017;Powell et al., 2018).