Cerebral Cortex Advance Access originally published online on November 24, 2004
Cerebral Cortex 2005 15(8):1113-1122; doi:10.1093/cercor/bhh210
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© Oxford University Press 2004; all rights reserved
Cross-modal integration and plastic changes revealed by lip movement, random-dot motion and sign languages in the hearing and deaf
1 National Institute for Physiological Sciences, Okazaki, Japan, 2 Biomedical Imaging Research Center, Fukui University, Fukui, Japan, 3 JST (Japan Science and Technology Corporation)/RISTEX (Research Institute of Science and Technology for Society), Kawaguchi, Japan, 4 Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe, Japan, 5 Department of Education, Fukui University, Fukui, Japan, 6 Department of Education, Kanazawa University, Kanazawa, Japan and 7 Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
Address correspondence to Norihiro Sadato, MD, PhD, Division of Cerebral Integration, Department of Cerebral Research, National Institute for Physiological Sciences, Myodaiji, Okazaki, Aichi, 444-8585 Japan. Email: sadato{at}nips.ac.jp.
Sign language activates the auditory cortex of deaf subjects, which is evidence of cross-modal plasticity. Lip-reading (visual phonetics), which involves audio-visual integration, activates the auditory cortex of hearing subjects. To test whether audio-visual cross-modal plasticity occurs within areas involved in cross-modal integration, we used functional MRI to study seven prelingual deaf signers, 10 hearing non-signers and nine hearing signers. The visually presented tasks included mouth-movement matching, random-dot motion matching and sign-related motion matching. The mouth-movement tasks included conditions with or without visual phonetics, and the difference between these was used to measure the lip-reading effects. During the mouth-movement matching tasks, the deaf subjects showed more prominent activation of the left planum temporale (PT) than the hearing subjects. During dot-motion matching, the deaf showed greater activation in the right PT. Sign-related motion, with or without a lexical component, activated the left PT in the deaf signers more than in the hearing signers. These areas showed lip-reading effects in hearing subjects. These findings suggest that cross-modal plasticity is induced by auditory deprivation independent of the lexical processes or visual phonetics, and this plasticity is mediated in part by the neural substrates of audio-visual cross-modal integration.
Key Words: blood flow • cortex • deafness • language • magnetic resonance • speech
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. E. Doucet, F. Bergeron, M. Lassonde, P. Ferron, and F. Lepore Cross-modal reorganization and speech perception in cochlear implant users Brain, December 1, 2006; 129(12): 3376 - 3383. [Abstract] [Full Text] [PDF]
|
|