Plasticity and Multimodality in Oral Communication for the Deaf – PlasMody

The major goal of the PlasMody project is to better understand the mechanisms of speech perception and production in deaf before and after cochlear implantation. A specific emphasis will be made on the role of multisensory interactions and crossmodal compensation in the access to orality by cochlear implanted deaf patients. From the scientific prospective, PlasMody represents an efficient tool to study or investigate the mechanisms of multisensory interactions which are fundamental for speech comprehension. From the clinical standpoint, our studies on hearing recovery in deaf children will provide crucial information to guide speech therapy reeducation and technological substitutes.
Important progress has been made on cochlear implantation (CI), allowing patient suffering of a profound deafness to recover most of auditory functions and recently prescription has been enlarged to children of less than two years of age. This success induced a complete reappraisal of hearing loss reeducation because the implantation is very efficient to support young children acquiring oral speech. While most of speech information can be obtained through the auditory channel, visual information can greatly improve speech intelligibility. Considering the crude information delivered by the implant, CI deaf subjects have taken advantage of the multimodality of speech by developing supranormal visual skills of speech comprehension. In this frame of crossmodal compensation, a first PlasMody objective is to understand how CI subject exploit vision and efficiently combine it with recovered audition to process complex information derived from Cued-Speech or normal speech, including segmental and prosodic information about the linguistic content, together with speaker identity and emotional state. We assume that the synergy between vision and audition during post-implantation recovery acts as a positive feedback loop leading to an increase of performance in the auditory modality. Similarly, in line with a motor theory of speech perception, PlasMody will assess if the sensory-motor interactions could create cross-improvement between perception and production following cochlear implantation. Lastly, PlasMody will decode visual features of Cued-speech in deaf communications to insert them into automatic conversion procedure for assisted communication systems.
PlasMody is at the crossroad of cognitive neuropsychology, clinical research and communication technology. Consequently PlasMody is translational and multidisciplinary in several aspects of its architecture, it encompasses psychophysics, brain imaging and technology-assisted communication systems with the unique objective to understand the compensatory mechanisms induced by hearing loss to allow cochlear implanted deaf patient to access oral communication.