Ålderseffekter av en kritisk period för språkutveckling : Grammatisk intuition hos hörande infödda teckenspråkiga

Sammanfattning: This thesis reports on a study on the ultimate attainment of grammatical intuition in Swedish in 29 adult hearing native signers, bilingual in Swedish Sign Language and Swedish. It is reasoned that measures of such intuition in adults may indicate implicit linguistic entrenchment in Swedish during early language development. Although Sign Language Linguistics and Second Language Research on deaf signers are two established fields of research in Sweden, there is little research on hearing native signers. A few international studies have focused on early child language development in hearing native signers, showing that these children develop their two languages simultaneously from birth even if the signed language dominates the linguistic environment. However, studies focusing on older children indicate that their morphological and syntactic proficiency in the majority language resembles that of second language learners. Deductively this paper rests on neurobiological and psycholinguistic theories claiming that early language development is naturally and genetically constrained within a critical or maturational period. Grammatical intuition was measured through the use of two versions of a GJT-test (written and auditory) and a cloze test. The results showed that the average grammatical intuition of the hearing native signers was comparable to that of a group of early L2 learners of Swedish, but significantly different from that of a group of native speakers of Swedish, indicating that for some of the native signers, Swedish might have been successively learned. This thesis contributes unique data to second language research, while shedding a light on a group of bilinguals that is scarcely known to the study of linguistics.