Brain region becomes active in people born blind when they touch a 3D model of a face with their hands, suggesting that this area does not require visual experience to develop a preference for faces

Visual experience is not necessary for the development of face-selectivity in the lateral fusiform gyrus. N. Apurva Ratan Murty, Santani Teng, David Beeler, Anna Mynick, Aude Oliva, and Nancy Kanwisher. Proceedings of the National Academy of Sciences, August 24, 2020. https://doi.org/10.1073/pnas.2004607117

Significance: Here we show robust face-selectivity in the lateral fusiform gyrus of congenitally blind participants during haptic exploration of 3D-printed stimuli, indicating that neither visual experience, nor fovea-biased input, nor visual expertise is necessary for face-selectivity to arise in its characteristic location. Similar resting fMRI correlation fingerprints in individual blind and sighted participants suggest a role for long-range connectivity in the specification of the cortical locus of face-selectivity.

Abstract: The fusiform face area responds selectively to faces and is causally involved in face perception. How does face-selectivity in the fusiform arise in development, and why does it develop so systematically in the same location across individuals? Preferential cortical responses to faces develop early in infancy, yet evidence is conflicting on the central question of whether visual experience with faces is necessary. Here, we revisit this question by scanning congenitally blind individuals with fMRI while they haptically explored 3D-printed faces and other stimuli. We found robust face-selective responses in the lateral fusiform gyrus of individual blind participants during haptic exploration of stimuli, indicating that neither visual experience with faces nor fovea-biased inputs is necessary for face-selectivity to arise in the lateral fusiform gyrus. Our results instead suggest a role for long-range connectivity in specifying the location of face-selectivity in the human brain.

Keywords: face selectivitycongenital blindnessdevelopmenthapticsfusiform gyrus

Popular version: Face-specific brain area responds to faces even in people born blind - Study finds that the fusiform face area is active when blind people touch 3D models of faces. Anne Trafton. MIT News Office, August 26, 2020. https://news.mit.edu/2020/fusiform-brain-faces-blind-0826

More than 20 years ago, neuroscientist Nancy Kanwisher and others discovered that a small section of the brain located near the base of the skull responds much more strongly to faces than to other objects we see. This area, known as the fusiform face area, is believed to be specialized for identifying faces. 

Now, in a surprising new finding, Kanwisher and her colleagues have shown that this same region also becomes active in people who have been blind since birth, when they touch a three-dimensional model of a face with their hands. The finding suggests that this area does not require visual experience to develop a preference for faces. 

“That doesn’t mean that visual input doesn’t play a role in sighted subjects — it probably does,” she says. “What we showed here is that visual input is not necessary to develop this particular patch, in the same location, with the same selectivity for faces. That was pretty astonishing.”