Studies of neural processing in deaf signers: toward a neurocognitive model of language processing in the deaf

The ability to comprehend and produce language stands as a defining characteristic of human cognition and enables the transfer of knowledge and culture within human society. A proper characterization of the human capacity for language is required for the development of interventions that may be used to assist those individuals who have failed to achieve, or who have lost competence in, language behaviors. For signed languages, models of competent language use are lacking. This lack of knowledge hampers the development of effective assessment measures for deaf children who may be experiencing learning problems beyond those confronting the normal deaf child. I discuss two research avenues that have begun to provide a window into the neural systems involved in sign language processing: studies of language disruptions in adult deaf signers who have suffered brain injury, and studies of functional brain imaging in normal deaf signers. This research provides a basis for the development of a comprehensive neurocognitive model of sign language processing.