Research at the Rochester Institute of Technology (RIT) has found that expert sign-watching behavior is already present in babies by about 5 months of age.
Researcher and Assistant Professor Rain Bosworth and alumnus Adam Stone studied early-language knowledge in young infants and children by recording their gaze patterns as they watched a signer. The goal was to learn, from gaze patterns alone, whether the child was from a family that used spoken language or sign language at home.
They tested two groups of hearing infants and children that differed in their home language. One “control” group had hearing parents who spoke English and never used sign language or baby signs. The other group had deaf parents who only used American Sign Language at home. Both sets of children had normal hearing in this study. The control group saw sign language for the first time in the lab, while the other group was familiar with sign language.
The study, published in Developmental Science, showed that the non-signing infants and children looked at areas on the signer called “signing space,” in front of the torso. The hands predominantly fall in this area about 80 percent of the time when signing. However, the signing infants and children looked primarily at the face, and barely looked at the hands.
According to Bosworth, “At first, it does seem counter-intuitive that the non-signers are looking at the hands and signers are not. We think signers keep their gaze on the face because they are relying on highly developed and efficient peripheral vision. Infants who are not familiar with sign language look at the hands in signing space perhaps because that is what is perceptually salient to them.”