Development of adaptive communication skills in infants of blind parents

A fundamental question about the development of communication behaviour in early life is how infants acquire adaptive communication behaviour that is well-suited to their individual social environment, and how the experience of parent-child communication affects this development. The current study investigated how infants develop communication skills when their parents are visually impaired and cannot see their infants' eye gaze. We analysed 6- minute video-recordings of naturalistic interaction between 14 sighted infants of blind parents (SIBP) with a) their blind parent and b) a sighted experimenter. Data coded from these interactions were compared to those from 28 age-matched sighted infants of sighted parents (Controls). Each infant completed two visits, at 6-10 months and 12-16 months of age. Within each interaction sample, we coded the function (initiation or response) and form (face gaze, vocalisation, or action) of each infant communication behaviour. When interacting with their parents, SIBP made relatively more communicative responses than initiations, and used more face gaze and fewer actions to communicate, than did Controls. When interacting with a sighted experimenter, by contrast, SIBP made slightly (but significantly) more communicative initiations than Controls, but otherwise used similar forms of communication. The differential communication behaviour by infants of blind vs. sighted parents was already apparent by 6-10 months of age, and was specific to communication with the parent. These results highlight the flexibility in the early development of human communication behaviour, which enables infants to optimise their communicative bids and methods to their unique social environment