title: Cross-modal reorganization in cochlear implant users: Auditory cortex contributes to visual face processing.
abstract: There is converging evidence that the auditory cortex takes over visual functions during a period of auditory deprivation. A residual pattern of cross-modal take-over may prevent the auditory cortex to adapt to restored sensory input as delivered by a cochlear implant (CI) and limit speech intelligibility with a CI. The aim of the present study was to investigate whether visual face processing in CI users activates auditory cortex and whether this has adaptive or maladaptive consequences. High-density electroencephalogram data were recorded from CI users (n=21) and age-matched normal hearing controls (n=21) performing a face versus house discrimination task. Lip reading and face recognition abilities were measured as well as speech intelligibility. Evaluation of event-related potential (ERP) topographies revealed significant group differences over occipito-temporal scalp regions. Distributed source analysis identified significantly higher activation in the right auditory cortex for CI users compared to NH controls, confirming visual take-over. Lip reading skills were significantly enhanced in the CI group and appeared to be particularly better after a longer duration of deafness, while face recognition was not significantly different between groups. However, auditory cortex activation in CI users was positively related to face recognition abilities. Our results confirm a cross-modal reorganization for ecologically valid visual stimuli in CI users. Furthermore, they suggest that residual takeover, which can persist even after adaptation to a CI is not necessarily maladaptive.
authors.affiliation: Neuropsychology Lab, Department of Psychology, Carl von Ossietzky University Oldenburg, Germany. Electronic address: maren.stropahl@uni-oldenburg.de.
authors.forename: Maren
authors.initials: M
authors.lastname: Stropahl
authors.affiliation: Department of Phoniatrics, Pediatric Audiology and Neurootology, Evangelisches Krankenhaus Oldenburg, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Plotz
authors.affiliation: Department of Phoniatrics, Pediatric Audiology and Neurootology, Evangelisches Krankenhaus Oldenburg, Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Schönfeld
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Germany; Cluster of Excellence Hearing4all Oldenburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
authors.affiliation: Cluster of Excellence Hearing4all Oldenburg, Germany; Department of Neurology, Hannover Medical School, Germany.
authors.forename: Pascale
authors.initials: P
authors.lastname: Sandmann
authors.affiliation: Department of Psychology, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Galit
authors.initials: G
authors.lastname: Yovel
authors.affiliation: Cluster of Excellence Hearing4all Oldenburg, Germany; Department of Engineering Science, University of Oxford, UK; Methods in Cognitive Psychology, Department of Psychology, Carl von Ossietzky University Oldenburg, Germany.
authors.forename: Maarten
authors.initials: M
authors.lastname: De Vos
authors.affiliation: Neuropsychology Lab, Department of Psychology, Carl von Ossietzky University Oldenburg, Germany; Cluster of Excellence Hearing4all Oldenburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Debener
mesh_terms: D000328:Adult; D000368:Aged; D001303:Auditory Cortex / Q000502:physiology*; D003054:Cochlear Implants; D003638:Deafness / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008085:Lipreading; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D055815:Young Adult
keywords: Cochlear implant; Cross-modal reorganization; Lip reading; Source analysis; Visual face processing