Cochlear Implant Outcome and Functional Brain Organization in Deaf Subjects

Abstract

Using different and adapted brain-imaging techniques in congenitally deaf children and postlingually deafened adults, we identified neural patterns that are consistently predictive of speech perception performance with a cochlear implant. Deaf subjects who show neural activity in ventral regions of the brain during deafness, whether to communicate or just when idling at rest, tend to become poor performers. By contrast, those who involve dorsal brain regions in the same cognitive situations tend to become good performers. We further show that cortical reorganization does not only reflect hearing loss and its duration, but also the functional relevance of the cognitive operations that are performed during deafness. We argue that the trajectory toward one or the other pattern of cortical activity could be controlled by appropriate cognitive training during the period of deafness preceding cochlear implantation.