Vanderbilt Clinical Trials

to participate in this study. 1. Male or female individuals between the ages of 31 - 84 months (2.5 - 7 years chronological age) at the time of consent. 2. Generally healthy with no acute illnesses. 3. Normal or corrected-to-normal vision with visual acuity and oculomotor function sufficient to watch short videos. 4. Hearing adequate to hear information presented in age-appropriate videos of social interactions. 5. Subject and parent (or legally authorized representative) are able and agree to attend the required study visit and complete the full battery of psychometric assessments and questionnaires (electronically or in-person where required). 6. Subject's parent (or legally authorized representative) can understand information, instructions, and videos presented in the English language. 7. Subject's parent (or legally authorized representative) can read and understand the Informed Consent Form (ICF). 8. Subject's parent (or legally authorized representative) provides written informed consent allowing the child subject to participate in the study. NOTE: where able, the child subject should also provide assent. Subjects who meet any of the following

are not eligible to participate in this study: 1. Known genetic disorders (e.g., Fragile X, Williams Syndrome, Tuberous Sclerosis, Muscular Dystrophy, Neurofibromatosis, Down Syndrome). 2. Severe hearing or visual impairment (e.g., congenital nystagmus, congenital cataracts, previous diagnosis of severe hearing deficits by otoacoustic emissions or auditory brainstem response), which in the opinion of the investigator, would limit the child from completing the EarliPoint eye-tracking procedure or clinical reference assessments. (Note: Corrective lenses are allowable up to a prescription of +/- 5.0.) 3. Acute illnesses likely to prevent successful or valid data collection, i.e., conjunctivitis, fever, uncontrolled allergy symptoms, etc. 4. Subject has an uncontrolled seizure disorder. 5. History or presence of a clinically significant medical disease or a mental state that might confound the study or be detrimental to the subject in the opinion of the investigator. 6. Acute exacerbations of chronic illnesses likely to prevent successful or valid data collection. 7. Receiving therapies that may affect the subject's vision, (i.e., currently receiving or have received the following therapies within 2 weeks of screening: topiramate, chlorpromazine, thioridazine, prednisone, prednisolone (including ophthalmic solutions and ointments), diphenhydramine, or hydroxyzine; or have received ophthalmic antibiotics within 3 days of screening: tobramycin, ciprofloxacin, gatifloxacin, levofloxacin, moxifloxacin and ofloxacin solutions and/or bacitracin ointment). 8. Receiving therapies that may affect the subject's ability to focus attention on the videos, (i.e., if on central nervous system stimulants, Central Nervous System (CNS) depressants, or anticonvulsants, dose must have been stable for at least 2 weeks). 9. Subject is unable or unwilling to undergo EarliPoint testing for up to 20 minutes per assessment (e.g., child has frequent tantrums and tantrums do not subside within 5 minutes). 10. In the opinion of the investigator, the subject and/or parent (or legally authorized representative) are unable, unwilling, or unlikely to comply with all study required procedures and follow-up assessments or to complete the full battery of psychometric assessments (electronically or in-person where required). 11. Subject is receiving or plans to receive any investigational drug or device for the duration of their participation in this study. 12. In the opinion of the Investigator, subject is not a suitable candidate for participation in a research study (NOTE: reason must be specified).