An Eye-Tracking Measure of Joint Attention as an Autism Spectrum Disorder Endophenotype: Initial Validation in a Community Sample of Adults, Typically Developing Children, and Children with Autism Spectrum Disorder

An important milestone in children's early social-communicative development is the ability to respond to others' bids for joint attention (RJA). It is well established that this ability to respond to another's gaze direction is a specific deficit in children with an autism spectrum disorder (ASD). We examined visual attention allocation during a set of social video vignettes that are intended elicit the coordination of attention with another person. This eye-tracking measure utilized modern technology to evaluate how individuals allocated their visual attention while watching social video vignettes. These videos display an adult model who gazes at a series of targets that appear and disappear in the four corners of the screen (congruent condition). Gaze allocation in the experimental condition is compared to a set of control stimuli where the model's gaze moves equally as often, but is not directed at the appearing/disappearing targets (incongruent condition). Feasibility of administering this experimental paradigm to typically developing adults (n = 44), children (n = 50), and children with ASD ( n = 23) is evaluated. The performance of children with ASD and typically developing children is also compared on a battery of theory of mind tasks intended to evaluate children's ability to interpret the mental states of others. Results revealed several major findings. First, gaze allocation of adults and typically developing children differed significantly between the congruent and incongruent conditions. Second, individual differences in gaze allocation were significantly predicted by features of the broad autism phenotype (BAP) in adults and typically developing children. Third, children with autism spectrum disorder scored significantly lower on theory of mind tasks when compared to typically developing children. Fourth, across both groups of children the Social Awareness Subscale form the Social Responsiveness Scale (SRS), a parent-report measure evaluating features of the broad autism phenotype, significantly predicted gaze allocation during our experimental eye-tracking stimuli and performance on theory of mind tasks. Fifth, also across both groups, theory of mind scores predicted gaze allocation during our eye-tracking measure of joint attention. These findings are consistent with the notion that our eye-tracking measure of gaze following captures a valid endophenotype associated with ASD.