Cochlear implantation (CI) for profound @entity393 , while often successful in restoring hearing to the deaf @entity1 , does not always result in effective speech processing. Exposure to non-auditory signals during the pre-implantation period is widely held to be responsible for such failures. Here, we question the inference that such exposure irreparably distorts the function of auditory cortex, negatively impacting the efficacy of CI. Animal studies suggest that in @entity2319 there is a disconnection between (disordered) activation in primary auditory cortex (A1) and activation in secondary auditory cortex (A2). In @entity1 , one factor contributing to this functional decoupling is assumed to be abnormal activation of A1 by visual projections-including exposure to sign language. In this paper we show that that this abnormal activation of A1 does not routinely occur, while A2 functions effectively supramodally and multimodally to deliver spoken language irrespective of hearing status. What, then, is responsible for poor outcomes for some individuals with CI and for apparent abnormalities in cortical organization in these @entity1 ? Since infancy is a critical period for the acquisition of language, deaf @entity1 born to hearing parents are at risk of developing inefficient neural structures to support skilled language processing. A sign language, acquired by a deaf @entity1 as a first language in a signing environment, is cortically organized like a heard spoken language in terms of specialization of the dominant perisylvian system. However, very few deaf @entity1 are exposed to sign language in early infancy. Moreover, no studies to date have examined sign language proficiency in relation to cortical organization in individuals with CI. Given the paucity of such relevant findings, we suggest that the best guarantee of good language outcome after CI is the establishment of a secure first language pre-implant-however that may be achieved, and whatever the success of auditory restoration.

Cochlear implantation (CI) for XXXX : the relevance of studies of brain organization and the role of first language acquisition in considering outcome success.

@entity1 :: ('9606', 'Species') :: ['children', 'humans', 'people', 'child'] @entity393 :: ('MESH:D034381', 'Disease') :: ['congenital hearing impairment'] @entity2319 :: ('MESH:D003638', 'Disease') :: ['congenital early deafness']
@entity2319 :: (MESH:D003638,Disease) :: ['prelingual deafness']
