Gaze Abnormality Can Distinguish Between Autism Spectrum Disorder and Typically Developing Children through Screening in 5-Year-Old Children By a Double Blind Study in a Japanese Community Based Population

Background:  A number of studies have identified unique visual gaze patterns in individuals with autism spectrum disorder (ASD) using eye-tracking systems. Such gaze fixation patterns in individuals with ASD are considered to be associated with social attention. However, the past studies show different results between ASD and typically developing (TD).

Objectives: Using Gazefinder, an all-in-one eye-tracking system for early detection of ASD in toddlers, we examined the gaze characteristics of toddlers to specific objects in individuals with and without ASD in a 5-year-old children by a double blind study in Japanese community based population.

Methods: We measured the percentage of eye fixation time allocated to particular objects depicted in movies by five-year-old children in a community health check-up (n=438) by double blind study. In the community health check-up spanning three years (2013-2015, N=3804), the participants screened in the community health check-up were 2923 children. The local government officers invited 440 children (included 31 applicants) to additional assessments and an interview based on the results of the screening. Subjects of analysis are ASD (n=84) who diagnosed by DSM-5 criteria and TD (n=98) who had no abnormalities in all the experiment. We compared these percentages between the two groups. Gazefinder incorporates movies of human faces, biological motion, and people and geometric shapes, and it provides almost instantaneous data by automatically calculating the percentage fixation time allocated by the participants among regions of interest in the movie. In addition to the total trial time is short (approximately 2 min), and instructions or verbal answers are not required; the participant simply views a video monitor.

Results: Compared with the TD group, the ASD group showed significantly less fixation time at locations of salient social information (the available percentage fixation time, ‘eyes’ region in the movie of human faces without lip movement, ‘mouth’ region with talking and ‘people’ region in the movie of people and geometry), while there were no significant group wise differences in the responses to biological motion. However, the percentage fixation times exhibited small effect sizes for the group difference. In ROC analysis in each area of interest, the significant AUCs were .600 (‘eyes’ region, silent), .590 (‘mouth region’, talking), .652 and .586 (‘people’ region, same size and small size). AUCs were low accuracy (<0.7).

Conclusions: This study showed gaze abnormalities can distinguish ASD and TD through screening, in order to improve the accuracy of screening, it is necessary to examine further these contents.