Gaze Patterns During an Eye-Tracking Measure of Joint Attention in Typically Developing Children and Children with Autism Spectrum Disorder

Background:  Longitudinal research that followed children with ASD over time found that many children eventually acquired the ability to respond to an adults’ pointing gesture (Sigman & Ruskin, 1999). Despite these increases in social responsiveness, it remains unclear whether deficits in spontaneous gaze following persist across the autism spectrum and age span. Modern eye-tracking technology may be ideally suited to evaluate spontaneous gaze following across the age span.

Objectives:  The current eye-tracking study evaluates children’s gaze patterns while viewing a dynamic paradigm that elicits spontaneous gaze following. We predict that children’s gaze patterns differ between diagnostic groups and are associated with individual differences in social awareness (SRS social awareness scores).

Methods:  The sample included 21 children with ASD (M=7.3 years, SD=1.5 years) and 24 typically developing children (TD group) (M=6.8 years, SD=1.6 years) from ethnically diverse backgrounds. The Social Responsiveness Scale (Constantino, 2002) was used to rule out ASD in typically developing children and the Autism Diagnostic Observation Schedules-General (ADOS-G; Lord et al., 2000) was used to confirm diagnoses in children with ASD. The samples were well matched on chronological age, gender (ASD, 18/3; TD, 20/4, M/F), and receptive language age (ASD M=85.10 months; TD M=86.83 months).

Children watched videos that displayed a model (Face AOI) who gazes at a series of targets (Target AOI) that appeared and disappeared in the four corners of the screen (congruent condition). Gaze patterns in the congruent condition were compared to a set of control stimuli where the model’s gaze was not directed at the targets (incongruent condition) (Swanson, Serlin, Siller, 2012). Gaze allocation to the Face and Target was evaluated based on total fixation duration. To quantify ‘sticky attention’ to non-social stimuli, we also evaluated the duration of children’s first fixation to the Target.

Results:  Results did not reveal significant group differences in children’s overall gaze allocation to the Target and Face AOI. However, findings showed significant group differences in the duration of children’s first fixation to the Target AOI, F=5.51, p<.05. When both groups were combined, parent report measures of children’s social awareness reliably predicted patterns of fixation duration to the Target (F=7.76, p<.01) and Face AOIs (F=3.96, p<.05), but not first fixation duration to the Target (F=1.96, p=.16). That is, individuals with better social awareness abilities showed reliable differences in fixation duration between the congruent and incongruent condition, while individuals with greater social disability showed indistinguishable fixation durations across both conditions.

Conclusions:  Key findings from this research showed that quantitative individual differences in visual fixation were predicted by continuous measures of social abilities and impairment, but not children’s diagnostic classifications. However, a qualitative measure of social salience (first fixation duration) did differ significantly between the two groups. This finding points to future directions for endophenotype research. By definition, endophenotypes aspire to be ‘elementary’ and closely related to the underlying neural circuitry of ASD. As a consequence, clinical measures used to validate candidate endophenotypes may be more successful if they capture a specific behavioral dimension of ASD rather than global diagnostic classifications.