title: Bimodal bilingualism as multisensory training?: Evidence for improved audiovisual speech perception after sign language exposure.
abstract: The aim of the present study was to characterize effects of learning a sign language on the processing of a spoken language. Specifically, audiovisual phoneme comprehension was assessed before and after 13 weeks of sign language exposure. L2 ASL learners performed this task in the fMRI scanner. Results indicated that L2 American Sign Language (ASL) learners' behavioral classification of the speech sounds improved with time compared to hearing nonsigners. Results indicated increased activation in the supramarginal gyrus (SMG) after sign language exposure, which suggests concomitant increased phonological processing of speech. A multiple regression analysis indicated that learner's rating on co-sign speech use and lipreading ability was correlated with SMG activation. This pattern of results indicates that the increased use of mouthing and possibly lipreading during sign language acquisition may concurrently improve audiovisual speech processing in budding hearing bimodal bilinguals.
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, United States; Program in Cognitive Science, Indiana University, United States; Speech and Hearing Sciences, Indiana University, United States. Electronic address: willjota@indiana.edu.
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Williams
authors.affiliation: Program in Cognitive Science, Indiana University, United States; Second Language Studies, Indiana University, United States.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Darcy
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, United States; Program in Cognitive Science, Indiana University, United States; Program in Neuroscience, Indiana University, United States.
authors.forename: Sharlene D
authors.initials: SD
authors.lastname: Newman
mesh_terms: D001921:Brain / Q000502:physiology*; D032882:Comprehension / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D019303:Multilingualism; D012813:Sign Language; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult
keywords: American Sign Language; Audiovisual speech; Bimodal bilingualism; Lipreading; Longitudinal fMRI study