Is there an alternative cerebral network associated with enhanced phonological processing in deaf speech-users? An exceptional case.
Most people born deaf and exposed to oral language show scant evidence of sensitivity to the phonology of speech when processing written language. In this respect they differ from hearing people. However, occasionally, a prelingually deaf person can achieve good processing of written language in terms of phonological sensitivity and awareness, and in this respect appears exceptional. We report the pattern of event-related fMRI activation in such a deaf reader while performing a rhyme-judgment on written words with similar spelling endings that do not provide rhyme clues. The left inferior frontal gyrus pars opercularis and the left inferior parietal lobe showed greater activation for this task than for a letter-string identity matching task. This participant was special in this regard, showing significantly greater activation in these regions than a group of hearing participants with a similar level of phonological and reading skill. In addition, SR showed activation in the left mid-fusiform gyrus; a region which did not show task-specific activation in the other respondents. The pattern of activation in this exceptional deaf reader was also unique compared with three deaf readers who showed limited phonological processing. We discuss the possibility that this pattern of activation may be critical in relation to phonological decoding of the written word in good deaf readers whose phonological reading skills are indistinguishable from those of hearing readers.
Laboratoire Cognition Langage et Développement, Université Libre de Bruxelles, Belgium. mario.aparicio@ulb.ac.be
Mario
M
Aparicio
Elisabeth
E
Demont
Daniel
D
Gounot
Marie-Noëlle
MN
Metz-Lutz
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003638:Deafness / Q000503:physiopathology*; D003657:Decision Making / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007600:Judgment / Q000502:physiology; D007802:Language; D007807:Language Tests; D008085:Lipreading; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010700:Phonetics; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011932:Reading; D014705:Verbal Behavior / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology