Apr 18, 2014
In Petitto (2000) we learn that babies exposed to spoken and sign languages detect patterns in language. Language acquisition transcends modality.
Hearing babies who are exposed to a signed and spoken language from birth (bilingual-bimodal) develop language similarly to monolingual babies. Bilingual-bimodal babies tend to produce simultaneous vocal and manual babbling. Deaf babies use their manual babbling differently than they use excitatory gestures (such as opening and closing of the hand and arm movements when presented with a new toy). Hearing infants are noted for attending to the sounds of their own speech when babbling. In the same way, Deaf babies tend to look at their hands while babbling, but do not do so when producing excitatory gestures. The features of babbling are similar for Deaf and hearing babies, though in different language modalities.
First words and first signs are produced within a matter of hours of each other. The first signs and first words may have semantic (a.k.a. meaning) overlaps. That is, the first acquired word in both ASL and English is “dog.” The first signs and first words may also be “mutually exclusive”- for example, acquiring “dog” in one language and “more” in the other. These finding are in line with what has been found among hearing bilinguals. The brain is not hardwired for spoken language only, but for the patterning of language whether on the hands or the tongue.
On the Biological Foundations of Human Language. Petitto (2000) In H. Lane & K. Emmorey (Eds.), The signs of language revisited: An anthology in honor of Ursula Bellugi and Edward Klima (pp. 447-471). Mahwah, NJ: Lawrence Erlbaum. Please see Petitto’s published papers and abstracts here.
Keywords: Signed and spoken language milestones, babbling, bilingualism