title: Enhanced visual adaptation in cochlear implant users revealed by concurrent EEG-fNIRS.
abstract: Previous studies have observed lower visual cortex activation for visual processing in cochlear implant (CI) users compared to normal hearing controls, while others reported enhanced visual speechreading abilities in CI users. The present work investigated whether lower visual cortical activation for visual processing can be explained by a more efficient visual sensory encoding in CI users. Specifically, we investigated whether CI users show enhanced stimulus-specific adaptation for visual stimuli compared to controls. Auditory sensory adaptation was also investigated to explore the sensory specificity of the predicted effect. Twenty post-lingually deafened adult CI users and twenty age-matched controls were presented with repeated visual and auditory stimuli during simultaneous acquisition of electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). By integrating EEG and fNIRS signals we found significantly enhanced visual adaptation and lower visual cortex activation in CI users compared to controls. That is, responses to repeated visual stimuli decreased more prominently in CI users than in controls. The results suggest that CI users process visual stimuli more efficiently than controls.
authors.affiliation: Neuropsychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany. Electronic address: ling-chia.chen@uni-oldenburg.de.
authors.forename: Ling-Chia
authors.initials: LC
authors.lastname: Chen
authors.affiliation: Neuropsychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Stropahl
authors.affiliation: International Laboratory for Brain, Music and Sound Research (BRAMS), Université de Montréal, Montréal, Québec, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Schönwiesner
authors.affiliation: Neuropsychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany; Cluster of Excellence Hearing4all, Germany; Research Center Neurosensory Science, University of Oldenburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Debener
mesh_terms: D000161:Acoustic Stimulation; D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D001303:Auditory Cortex / Q000503:physiopathology*; D001307:Auditory Perception / Q000502:physiology; D003054:Cochlear Implants; D003638:Deafness / Q000378:metabolism / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D019265:Spectroscopy, Near-Infrared; D014793:Visual Cortex / Q000378:metabolism / Q000503:physiopathology*; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
keywords: Cochlear implant; Plasticity; Simultaneous EEG-fNIRS; Stimulus-specific adaptation