Positron Emission Tomography Imaging of Brain Reorganisation of the Central Auditory Cortex in Asymetrical Profound Deaf Patient With a Cochlear Implantation.

Positron Emission Tomography Imaging of Brain Reorganisation of the Central Auditory Cortex in Asymetrical Profound Deaf Patient With a Cochlear Implantation

Our main objective is to study how the extent of reorganization of the central auditory system is related to the binaural integration in cochlear implanted subjects with asymmetric hearing loss. Subjects with asymmetric hearing loss treated with a cochlear implant and a control group of normal hearing subjects will perform two tests for binaural integration (speech recognition in noise and spatial localization) and two tasks of non-linguistic sounds perception.

Cochlear implantation is the most efficient method to restore hearing in deaf patients. However, about 2/3 of patients have some residual hearing and these patients usually combine two types of auditory information (electrical and acoustical). It is important to know how the brain is processing during two distinct stimulations and how it is related to the auditory level of performance.

Patients and controls will undergo a positron emission tomography scan brain imaging session during a simplified voice/non-voice discrimination task. For each tasks and brain imaging sessions, patients will be stimulated either with the non-implanted ear (acoustical stimulation), the cochlear implant (electrical stimulation) and using both modalities in a binaural condition.

Inclusion Criteria:

• cochlear implantation>3 months
• signature of informed consent
• affiliation to social service.

Exclusion Criteria:

• associated neurological disorder
• protected subjects
• epilepsy episodes
• psychotropic medication
• pregnancy