Sign language is a fully natural visual-manual language used by Deaf communities, with linguistic structure equivalent in complexity to spoken languages. It utilizes hand shapes, movements, locations in space, along with facial expressions and body posture, to convey vocabulary and grammatical information. Each Deaf community typically has its own sign language (for example, American Sign Language – ASL – in the U.S. and Canada, British Sign Language – BSL – in the UK), and these are not universal or merely signed versions of spoken languages but distinct languages with their own syntax and lexicon. Research in cognitive neuroscience has shown that sign languages engage the same brain regions used for spoken language, and that Deaf children exposed to sign language from birth acquire it on a similar developmental timeline as hearing children acquire speech.
Sandler, Wendy, and Diane Lillo-Martin. 2006. Sign Language and Linguistic Universals. Cambridge, UK: Cambridge University Press. Link
MacSweeney, Mairéad, et al. 2008. “The Signing Brain: The Neurobiology of Sign Language.” Trends in Cognitive Sciences 12 (11): 432–440. Link
