Differentiating the use of gaze in bilingual-bimodal language acquisition: a comparison of two sets of twins with deaf parents.

Signed languages make unique demands on gaze during communication. Bilingual children acquiring both a spoken and a signed language must learn to differentiate gaze use for their two languages. Gaze during utterances was examined for a set of bilingual-bimodal twins acquiring spoken English and American Sign Language (ASL) and a set of monolingual twins acquiring ASL when the twins were aged 2;0, 3;0 and 4;0. The bilingual-bimodal twins differentiated their languages by age 3;0. Like the monolingual ASL twins, the bilingual-bimodal twins established mutual gaze at the beginning of their ASL utterances and either maintained gaze to the end or alternated gaze to include a terminal look. In contrast, like children acquiring spoken English monolingually, the bilingual-bimodal twins established mutual gaze infrequently for their spoken English utterances. When they did establish mutual gaze, it occurred later in their spoken utterances and they tended to look away before the end.