Early Social Experience Affects the Development of Eye Gaze Processing

Eye gaze is a key channel of non-verbal communication in humans [1-3]. Eye contact with others is present from birth [4], and eye gaze processing is crucial for social learning and adult-infant communication [5-7]. However, little is known about the effect of selectively different experience of eye contact and gaze communication on early social and communicative development. To directly address this question, we assessed 14 sighted infants of blind parents (SIBPs) longitudinally at 6-10 and 12-16 months. Face scanning [8] and gaze following [7, 9] were assessed using eye tracking. In addition, naturalistic observations were made when the infants were interacting with their blind parent and with an unfamiliar sighted adult. Established measures of emergent autistic-like behaviors [10] and standardized tests of cognitive, motor, and linguistic development [11] were also collected. These data were then compared with those obtained from a group of infants of sighted parents. Despite showing typical social skills development overall, infants of blind parents allocated less attention to adult eye movements and gaze direction, an effect that increased between 6-10 and 12-16 months of age. The results suggest that infants adjust their use of adults' eye gaze depending on gaze communication experience from early in life. The results highlight that human functional brain development shows selective experience-dependent plasticity adaptive to the individual's specific social environment.