CI may provide deaf children with a good opportunity to develop language skills, but severe difficulties in early social experiences and interaction mediated by language still remain. Delays in these aspects suggest that interventions improving pragmatic skills are recommended even on very young children with CI.

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 (magnetoencephalography 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 borndeaf 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.cross-modal plasticity | deafness | modularity | ventral stream | identity processing T he human brain is endowed with the fundamental ability to adapt its neural circuits in response to experience. Sensory deprivation has long been championed as a model to test how experience interacts with intrinsic constraints to shape functional brain organization. In particular, decades of neuroscientific research have gathered compelling evidence that blindness and deafness are associated with cross-modal recruitment of the sensory-deprived cortices (1). For instance, in early deaf individuals, visual and tactile stimuli induce responses in regions of the cerebral cortex that are sensitive primarily to sounds in the typical hearing brain (2, 3).Animal models of congenital and early deafness suggest that specific visual functions are relocated to discrete regions of the reorganized cortex and that this functional preference in crossmodal recruitment supports superior visual performance. For instance, superior visual motion detection is selectively altered in deaf cats when a portion of the dorsal auditory cortex, specialized for auditory motion processing in the hearing cat, is transiently deactivated (4). These results suggest that cross-modal plasticity associated with early auditory deprivation follows organizational principles that maintain the functional specialization of the colonized brain regions. In humans, however, there is only limited evidence that specific nonauditory inputs are differentially localized to discrete portions of the auditory-deprived cortices. For example, Bola et al. have recently reported, in deaf individuals, cross-modal activations for visual rhythm discrimination in t...

In 2 experiments we investigated attentional orienting to nonpredictive social and nonsocial cues in deaf observers. In Experiment 1a, 22 early deaf adults and 23 hearing controls performed a peripheral shape-discrimination task, while uninformative central gaze cues validly and invalidly cued the location of the target. As an adaptation to the lack of audition, we expected deaf adults to show a larger impact of gaze cuing on attentional orienting compared with hearing controls. However, contrary to our predictions, deaf participants did not respond faster to cued compared with uncued targets (gaze-cuing effect; GCE), and this behavior partly correlated with early sign language acquisition. Experiment 1b showed a reliable GCE in 13 hearing native signers, thus excluding a key role of early sign language acquisition in explaining the lack of GCE in the response times of deaf participants. To test whether the resistance to uninformative central cues extends to nonsocial cues, in Experiment 2 nonpredictive arrow cues were presented to 14 deaf and 14 hearing participants. Both groups of participants showed a comparable arrow-cuing effect. Together, our findings suggest that deafness may selectively limit attentional-orienting triggered by central irrelevant gaze cues. Possible implications for plasticity related to deafness are discussed.

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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 following 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 case of early sensory deprivation relates to the original functional specialization of the reorganized brain regions.