Functional selectivity for face processing in the temporal voice area of early deaf individuals

Significance Here, we show that deaf individuals activate a specific and discrete subregion of the temporal cortex, typically selective to voices in hearing people, for visual face processing. This reorganized “voice” region participates in face identity processing and responds selectively to faces early in time, suggesting that this area becomes an integral part of the face network in early deaf individuals. Observing that face processing selectively colonizes a region of the hearing brain that is functionally related to identity processing evidences the intrinsic constraints imposed to cross-modal plasticity. Our work therefore supports the view that, even if brain components modify their sensory tuning in case of deprivation, they maintain a relation to the computational structure of the problems they solve. Brain systems supporting face and voice processing both contribute to the extraction of important information for social interaction (e.g., person identity). How does the brain reorganize when one of these channels is absent? Here, we explore this question by combining behavioral and multimodal neuroimaging measures (magneto-encephalography and functional imaging) in a group of early deaf humans. We show enhanced selective neural response for faces and for individual face coding in a specific region of the auditory cortex that is typically specialized for voice perception in hearing individuals. In this region, selectivity to face signals emerges early in the visual processing hierarchy, shortly after typical face-selective responses in the ventral visual pathway. Functional and effective connectivity analyses suggest reorganization in long-range connections from early visual areas to the face-selective temporal area in individuals with early and profound deafness. Altogether, these observations demonstrate that regions that typically specialize for voice processing in the hearing brain preferentially reorganize for face processing in born-deaf people. Our results support the idea that cross-modal plasticity in the case of early sensory deprivation relates to the original functional specialization of the reorganized brain regions.