title: Faster phonological processing and right occipito-temporal coupling in deaf adults signal poor cochlear implant outcome.
abstract: The outcome of adult cochlear implantation is predicted positively by the involvement of visual cortex in speech processing, and negatively by the cross-modal recruitment of the right temporal cortex during and after deafness. How these two neurofunctional predictors concur to modulate cochlear implant (CI) performance remains unclear. In this fMRI study, we explore the joint involvement of occipital and right hemisphere regions in a visual-based phonological task in post-lingual deafness. Intriguingly, we show that some deaf subjects perform faster than controls. This behavioural effect is associated with reorganized connectivity across bilateral visual, right temporal and left inferior frontal cortices, but with poor CI outcome. Conversely, preserved normal-range reaction times are associated with left-lateralized phonological processing and good CI outcome. These results suggest that following deafness, involvement of visual cortex in the context of reorganized right-lateralized phonological processing compromises its availability for audio-visual synergy during adaptation to CI.
authors.affiliation: Institut Arthur Vernes, ENT Surgery, 36 rue d'Assas, Paris 75006, France.|Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France.|University of Nottingham, School of Medicine, University Park Nottingham NG7 2UH, Nottingham, UK.
authors.forename: Diane S
authors.initials: DS
authors.lastname: Lazard
authors.affiliation: Department of Neuroscience, University of Geneva, Campus Biotech, 9 chemin des Mines, Geneva 1202, Switzerland.
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Giraud
mesh_terms: D000328:Adult; D001519:Behavior; D003054:Cochlear Implants; D003638:Deafness / Q000503:physiopathology* / Q000523:psychology / Q000534:rehabilitation; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009778:Occipital Lobe / Q000503:physiopathology*; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000503:physiopathology*; D016896:Treatment Outcome; D014796:Visual Perception