Speech lateralization in deaf populations: evidence for a developmental critical period.
Cerebral lateralization for speech in right-handed normal hearing and deaf adolescents was assessed using the dual-task paradigm. Subjects with normal hearing and deafness acquired after 3 years of age displayed left hemispheric dominance for speech production, whereas both congenitally deaf and those with an early acquired deafness (onset 6-36 months) showed atypical, anomalous cerebral representation. These results suggest the presence of a developmental critical period for cerebral lateralization during which exposure to adequate environmental stimulation may be needed to activate left hemispheric dominance for speech.
Department of Psychiatry and Human Behavior, Brown University Program in Medicine, RI.
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Marcotte
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Morere
D000293:Adolescent; D000328:Adult; D001288:Attention; D003423:Critical Period, Psychological; D003638:Deafness / Q000523:psychology*; D004292:Dominance, Cerebral; D007839:Functional Laterality; D006801:Humans; D007805:Language Development Disorders / Q000523:psychology*; D011597:Psychomotor Performance; D013067:Speech Perception