| Abstract | Cochlear implants are neuroprostheses designed to restore speech perception in case of profound bilateral hearing loss. As speech is fundamentally an audiovisual percept, a deficit in processing auditory information might lead to changes in audiovisual integration of speech comprehension. Using vowel-consonant-vowel stimuli under unimodal, audiovisual congruent and audiovisual incongruent (McGurk) conditions, we tested postlingually deaf cochlear-implanted (CI) users and normally hearing (NH) subjects in order to investigate their audiovisual perceptive strategies. Mode/Place-of-articulation perceptive analysis and information transmission analysis of congruent and incongruent percepts indicated a similar sensory specialization for CI users when compared to NH subjects, with voicing and nasality cues transmitted via audition and place cues principally transmitted via vision. NH as well as CI subjects underwent typical McGurk illusory percepts. However, while normally hearing subjects show a well-balanced bimodal integration of incongruent speech, we demonstrated that cochlear implantees present a bias toward a visual-predominant bimodal integration. Our results are complementary to previous studies showing that CI users maintain a high level of speechreading, even after several years of recovery of auditory speech comprehension. Altogether, our results suggest a cross-modal reorganization of speech comprehension in cochlear-implanted patients that might recruit more strongly than in NH the visual and visuo-auditory brain areas involved in speechreading. |
| Authors | Julien Rouger, Bernard Fraysse, Olivier Deguine, Pascal Barone
(Affiliation: Centre de Recherche Cerveau et Cognition, UMR CNRS 5549, Faculté de Médecine de Rangueil, Toulouse Cedex 9, France.)
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| Journal | Brain research
(Brain Res)
Vol. 1188
Pg. 87-99
(Jan 10 2008)
ISSN: 0006-8993 Netherlands |
| PMID | 18062941
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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| Topics |
- Acoustic Stimulation
- Adult
- Cerebral Cortex
(physiology)
- Cochlear Implants
- Cues
- Deafness
(physiopathology, therapy)
- Female
- Humans
- Illusions
(physiology)
- Language Tests
- Male
- Middle Aged
- Neural Pathways
(anatomy & histology, physiology)
- Neuronal Plasticity
(physiology)
- Photic Stimulation
- Reading
- Recovery of Function
(physiology)
- Speech Perception
(physiology)
- Visual Perception
(physiology)
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