Orienting to and away from the eyes in infants at high likelihood for autism when scanning faces

Abstract

This study employed eye-tracking technology to investigate the mechanisms underlying reduced gaze towards the eyes in infants at high likelihood (HL) for autism, specifically examining whether it results from avoidance triggered by heightened arousal when looking at the eyes or due to indifference to the eyes (i.e., unwilling to orient to the eyes). Infants at HL for autism and typically developing (TD) infants aged within 24 months were tested. In the experiment, participants' gaze was initially guided to the eye or mouth region immediately before the onset of the face. Latency to orient away from the guided regions, latency to orient to the eyes, and the location of the secondary fixation following the onset of the face were measured. The results showed that: (1) The HL infants looked less at eyes than TD infants; (2) Compared with TD infants, HL infants oriented towards eyes more slowly after being guided to the mouth; (3) After being guided to the eyes, HL infants' secondary fixation fell less in the eye region, and their latency to orient away from the eyes was also tended to be shorter. These results suggest that reduced eye-looking time was presented in HL infants, which was further explained by both eye avoidance and indifference to the eyes. Our study contributes theoretically to understanding the atypical face scanning pattern in autistic people and its related underlying mechanisms. Furthermore, our study provides important insights into the development of early screening tools and intervention protocols for autistic people.