Do you wonder about... sign language?
What brain activities are like in English speakers and Ameslan signers? See Brain + Language.
Do babies babble in sign language like those babies do in speech language? See Babbling.
"The human brain does not discriminate between the hands and the tongue. People discriminate, but not our biological human brain." -- Dr. Laura-Ann Petitto (Gallaudet Today, Spring 2012, p. 17)