LONDON, Aug. 28 (UPI) -- In a study using British Sign Language, signers made different mistakes in the sign and mouthing, meaning hand and lip movements are separate, researchers say.
David Vinson of University College London and colleagues propose hand and lip movements are separated in the signer's brain. Vinson explains when study participants translated English words into British Sign Language, the hands sometimes made a mistake but the lips didn't.
The study, published in Psychological Science, suggests differences in signs and in mouthing indicated hand and lip movements are not part of the same sign.
"In essence, they're doing the same thing as reading an English word aloud without pronouncing it," Vinson says in a statement. "So they seem to be processing two languages at the same time."
Vinson and colleagues recruited both deaf and hearing signers who had grown up signing with deaf parents. The participants sat in front of a video camera and were asked to sign pictures or words shown on a monitor -- shown at a fast pace to encourage mistakes that may reveal how language is processed.
Vinson noted British Sign Language is a separate language from both English and American Sign Language.
