title: First language acquisition differs from second language acquisition in prelingually deaf signers: evidence from sensitivity to grammaticality judgement in British Sign Language.
abstract: Age of acquisition (AoA) effects have been used to support the notion of a critical period for first language acquisition. In this study, we examine AoA effects in deaf British Sign Language (BSL) users via a grammaticality judgment task. When English reading performance and nonverbal IQ are factored out, results show that accuracy of grammaticality judgement decreases as AoA increases, until around age 8, thus showing the unique effect of AoA on grammatical judgement in early learners. No such effects were found in those who acquired BSL after age 8. These late learners appear to have first language proficiency in English instead, which may have been used to scaffold learning of BSL as a second language later in life.
authors.affiliation: Deafness, Cognition & Language Research Centre, University College London, 49 Gordon Square, London WC1H 0PD, England, United Kingdom. k.cormier@ucl.ac.uk
authors.forename: Kearsy
authors.initials: K
authors.lastname: Cormier
authors.forename: Adam
authors.initials: A
authors.lastname: Schembri
authors.forename: David
authors.initials: D
authors.lastname: Vinson
authors.forename: Eleni
authors.initials: E
authors.lastname: Orfanidou
mesh_terms: D000328:Adult; D002648:Child; D003423:Critical Period, Psychological; D060345:Education of Persons with Hearing Disabilities; D005260:Female; D006801:Humans; D007802:Language; D007804:Language Development; D008037:Linguistics; D008297:Male; D008875:Middle Aged; D011932:Reading; D012044:Regression Analysis; D012813:Sign Language