ABC-CT Pre-School Feasibility Study

The ABC-CT Pre-School Feasibility Study will collect data in a cohort of participants to determine feasibility of the measures used in the ABC-CT Phase 1 study and ABC-CT Confirmation study in 3-5 year old participants. We will be able to examine distributional and psychometric properties of the measures in this group and obtain preliminary estimates of group differences and associations with clinical measures. In addition, we aim to determine the viability of EEG and ET measures as potential biomarkers in 3-5-year-old children with ASD. Viability will be evaluated in terms of (a) valid data acquisition, including adequate levels of participant compliance, (b) reliability of data collection across sites, (c) construct validity in relation to social function, and (d) distributional/psychometric properties. Primary Objectives: 1. To evaluate the feasibility of collecting EEG and ET assessments used in the Phase 1 and Confirmation studies in 3-5 year old. 2. To determine the viability of adapted EEG and ET measures as potential biomarkers in 3-5-year-old children with ASD and TD. To further evaluate the psychometric properties of the ET and EEG biomarkers in the 3-5 year old population. Secondary Objectives: * To collect blood samples from all ASD subjects and their biological parents for future genomic analyses and to share raw, processed, and analyzed data via the National Database for Autism Research (NDAR) and National Institute of Health / National Institute of Mental Health (NIH/NIMH) Data Repositories to create a community resource accessible for use by all qualified investigators. * To compare estimates of key distributional parameters across the original, confirmation and feasibility samples to determine whether the markers profiles are sufficiently compatible to use in studies combining pre-school and school-aged children. The Preschool Feasibility sample will be evenly divided (25 ASD, 25 TD), aged 3-5, with IQ ranging from 60-150, recruited from 5 clinical implementation sites in the US. Endpoints: To collect and analyze a new cohort of participants to evaluate the feasibility of ET and EEG acquisition in 3-5 year olds. We will also evaluate ET and EEG measures for potential utility as biomarkers in clinical trials. Primary endpoints include evaluation of (1) Acquisition, (2) Construct Validity, (3) Discriminant Validity. Primary Biomarker Outcome Variables. 1. N170 Latency to Upright Human Faces: The N170 Latency to Upright Human Faces (N170 latency) is a scalp recorded EEG event-related potential (ERP) component elicited by perception of the upright human face. Recorded over the posterior-temporal right hemisphere, the latency (or speed) of the peak of the N170 ERP component occurs at approximately 200 msec in children aged 3 to 5 years of age. 2. Oculomotor Index of Gaze to Human Faces (OMI): Onscreen gaze position data, reflected in percentage of foveation (angling of the eyes to focus on a particular object) to human faces (Face%) relative to total valid foveation time across three assays.