Initiating Joint Attention: Reduced Gaze Alternation in Infancy Is Related to More ASD Symptomatology in Toddlerhood

Background:  Children with Autism Spectrum Disorder (ASD) are known to initiate Joint Attention (IJA) to a lesser extent than typically developing children. The incidence of higher level IJA behaviors, such as pointing, has been shown to discriminate between children at high vs. low risk (HR vs. LR) for ASD during the second year of life. It is less clear whether lower level IJA behaviors, such as the shifting of gaze between an interaction partner and an event occurring outside that person’s field of vision, can discriminate between groups. If valid, the measure would have the advantage of allowing earlier assessment than high level IJA behaviors.

Objectives: The aim of the present study was to assess whether the number of gaze shifts made between a person and an event occurring outside his/her field of vision could discriminate between HR and LR infants at 10 months, and to evaluate possible associations with later autism symptomatology as well as with higher level IJA behaviors.

 Methods: This face-to-face eye tracking study included a group of ten month old siblings of children with ASD (HR-group; N = 59) and a group of infant siblings of typically developing children (LR-group; N = 21). While the infant interacted with an adult experimenter, blinking lights appeared intermittently outside the experimenter’s field of vision. The number of gaze shifts made by the infant between the experimenter and the lights was used as the dependent measure. At 18 months, the infants were assessed with the ADOS-T, and correlations with the primary measure were calculated.

Results: The LR-group made more gaze shifts between the experimenter’s face and the lights at 10 months than did the HR-group, p < .05. This could not be explained by differences in the ability to disengage (assessed by a modified version of the AOSI disengagement task). Moreover, more alternating gaze behavior was associated with lower ADOS-T scores at 18 months in the HR-group, r = -.29, p < .05. Finally, making more gaze shifts at 10 months was associated with lower scores on the ADOS-T items showing, r = -.30, p < .05 and pointing, r = -.33, p< .05.

Conclusions: This study shows that alternating gaze behavior during face to face communication discriminates between infants at risk for ASD and controls, and that this measure relates to later ASD symptomatology in the HR group. These findings, together with the specific associations observed between alternating gaze and later pointing and showing behaviors, further validate alternating gaze behavior as a measure of IJA in infants. The measure has the advantage of allowing for earlier use than other IJA measures (e.g. pointing), and could potentially detect deviations in social behavior already during the first year of life. The study also highlights the potential of naturalistic paradigms in early ASD research.