Evaluating the Validity of an Eye Gaze Tracking Assessment Tool in Identifying Autism Spectrum Disorder

The current study will occur in four phases: pilot testing, development, validation, and re-test. In each phase, participants will view a visual attention stimulus with social elements (social attention paradigm) while eye tracking measurements are remotely acquired. The visual attention paradigm will be refined in the pilot testing but will remain the same for development, validation, and re-test phases. The entire process, including calibration and viewing of the visual paradigm, will take about 15 minutes. The text below describes each phase in detail and the reviews specific methodology for the social attention paradigm and eye tracking procedures.

1. Pilot Phase. Pilot testing of the social attention paradigm used to elicit eye gaze measurements to ensure they are sufficiently engaging across the ages of children participating. The visual attention paradigm during this phase is expected to be 10-12 minutes. This phase will also be used to determine optimal strategies for maintaining attention throughout the testing period. Initial data may also provide some insights into the most discriminating stimulus elements to include in future phases. Investigators anticipate recruiting approximately 10 ASD and 10 non-ASD participants in this phase. The pilot phase is expected to require 2.5 months of recruitment and 0.5 months of data reduction and analysis.
2. Development Phase. Once pilot testing is completed, 30 ASD-affected and 30 non-ASD children ages 1.5 to 18 will be recruited. Each child will complete the social attention paradigm while their eye gaze is remotely tracked. Eye gaze data is then scored for more than 100 parameters and these scores are entered into a database that includes diagnostic and cognitive information about each participant. The eye tracking data is then analyzed to create the diagnostic and prognostic algorithms that will refine the system's diagnostic sensitivity and specificity in the ASD population. The development period will require 6 months of data collection, followed by 3 months of scoring and algorithm computation.
3. Validation Phase. Collection of the validation sample will include 60 ASD-affected and 60 non-ASD affected children ages 1.5-18. The validation phase will use the same visual social attention paradigm and methods used in the development sample. The validation period will overlap algorithm development and require 8 months of data collection and 1 month of analysis.
4. Re-Test Phase. Participants in the re-test phase will include 30 ASD and 30 non-ASD children recruited in the first half of the validation phase. These participants will be explained in the validation phase that investigators will be re-recruiting them for the re-test phase approximately 3-6 months following their initial testing during the validation phase.

The target sample size varies depending on the phase of the study. Below are the target sample sizes for each phase:

Pilot Phase = 10 ASD and 10 Non-ASD Development Phase = 30 ASD and 30 Non-ASD Validation Phase = 60 ASD and 60 Non-ASD Re-Test Phase = 30 ASD and 30 Non-ASD (from the validation phase) The study population is individuals with autism spectrum disorder, or a clinical diagnosis of another developmental or psychiatric disorder (developmental/psychiatric controls), or have no specific developmental or psychiatric diagnosis (healthy controls), ages 1.5 (18 months) to 18 (120 months) at time of consent.

Eye gaze data will be collected using a remote eye tracker from Sensori-motoric instruments (SMI). Remote eye tracking offers minimal invasiveness to the viewer's field of view and collects time-stamped, 3D eye position, and binocular gaze and pupil data at a sampling rate of 120 Hz. Eye gaze capture is automatically calibrated to 2/5/9 points and provides position accuracy to 0.5° at a 60cm viewing distance. Gaze tracking data, screen recordings, user events, and gaze position will be recorded simultaneously. Data will be analyzed with emphasis on areas-of- interest and dwell time on specific targets on a second-by-second basis. Examples of the types of measures captured include: dwell time to any area of the stimulus, dwell time to the face and non-face regions of a human form on the video, fixation shifts between stimuli.