Plasticity in auditory cortex of the brain in Deaf people is not wasted. It's shifted to visual and tactile stimuli.
Eva M. Finney, Ione Fine & Karen R. Dobkins. "Visual stimuli activate auditory cortex in the deaf". Nature Neuroscience 4, 1171 - 1173 (2001). Published online: 12 November 2001; | doi:10.1038/nn763
Emmorey, Karen; Kosslyn, Stephen; and Bellugi Ursual. "Visual imagery and visual-spatial language: Enhanced imagery abilities in deaf and hearing ASL signers." Cognition, 46 (1993), pp 139-181. http://lcn.salk.edu/publications/1993/ Emmorey%20-%20Enhanced%20Imagery%20ASL%20signers%201993.pdf
Newman, A.J., Bavelier, D., Corina, D., Jezzard, P. and Neville, H.J. (2002) "A critical period for right hemisphere recruitment in American Sign Language processing." Nature Neuroscience, 5:76-80.
"The Angular Gyrus... " http://nro.sagepub.com/content/19/1/43.full
Posts: What is vision of the Deaf people like?.
The benefits of being bimodal and bilingual of Deaf people including deaf and hearing children of Deaf parents.
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