|Title||Signed words in the congenitally deaf evoke typical late lexicosemantic responses with no early visual responses in left superior temporal cortex.|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Leonard MK, Ramirez NFerjan, Torres C, Travis KE, Hatrak M, Mayberry RI, Halgren E|
|Date Published||2012 Jul 11|
|Keywords||Adolescent, Adult, Brain Mapping, Deafness, Evoked Potentials, Female, Functional Laterality, Humans, Magnetic Fields, Magnetic Resonance Imaging, Magnetoencephalography, Male, Photic Stimulation, Semantics, Sign Language, Temporal Lobe, Time Factors, Young Adult|
Congenitally deaf individuals receive little or no auditory input, and when raised by deaf parents, they acquire sign as their native and primary language. We asked two questions regarding how the deaf brain in humans adapts to sensory deprivation: (1) is meaning extracted and integrated from signs using the same classical left hemisphere frontotemporal network used for speech in hearing individuals, and (2) in deafness, is superior temporal cortex encompassing primary and secondary auditory regions reorganized to receive and process visual sensory information at short latencies? Using MEG constrained by individual cortical anatomy obtained with MRI, we examined an early time window associated with sensory processing and a late time window associated with lexicosemantic integration. We found that sign in deaf individuals and speech in hearing individuals activate a highly similar left frontotemporal network (including superior temporal regions surrounding auditory cortex) during lexicosemantic processing, but only speech in hearing individuals activates auditory regions during sensory processing. Thus, neural systems dedicated to processing high-level linguistic information are used for processing language regardless of modality or hearing status, and we do not find evidence for rewiring of afferent connections from visual systems to auditory cortex.
|Alternate Journal||J. Neurosci.|
|PubMed Central ID||PMC3418348|
|Grant List||R01 NS018741 / NS / NINDS NIH HHS / United States |
T-32 DC00041 / DC / NIDCD NIH HHS / United States
T32 DC000041 / DC / NIDCD NIH HHS / United States
T32 MH020002 / MH / NIMH NIH HHS / United States
Signed words in the congenitally deaf evoke typical late lexicosemantic responses with no early visual responses in left superior temporal cortex.