Measuring Word Understanding and Visual Attention Skills in Minimally Verbal/Non-Speaking Children with Autism - There are very few receptive language assessments which are appropriate for autistic children who are minimally verbal/non-speaking.2,7 Because practitioners use outcomes from these assessments to create intervention plans, identify appropriate augmentative and alternative communication (AAC) systems, and inform vocabulary selection for AAC systems, receptive language measures are a vital component of assessment and intervention for autistic children. Eye-tracking methods show promise as an alternative assessment method for this population because they do not require verbal skills, social interaction, or an overt motor response.10,11 The purpose of the proposed study is to examine the feasibility of using eye-tracking technology as a measure of implicit word comprehension for autistic children who are minimally verbal/non- speaking. The specific aims include (1) evaluating the feasibility of using eye-tracking technology, with pictures and object-stimuli, as an implicit measure of word understanding in autistic children who are minimally verbal/non-speaking, and (2) examining eye-movement variables which can be indices of word-understanding in this population. This study will include 35 autistic children who are minimally verbal/non-speaking. Participants will complete two experimental word-understanding eye-tracking assessments: a) an assessment that uses objects as stimuli, and b) an assessment that uses picture stimuli. Aim 1 will evaluate percent unusable data and percent completion of the two experimental eye-tracking tasks to add to the limited available information regarding feasibility of eye-tracking with this population. Behavioral coding will be used to describe participant behavior during unusable trials (i.e., trials with data loss) and during calibration failure. Unusable data may be a result of attentional difficulties, excess movement, or noncompliance. Results from behavioral coding will provide nuanced information about participant behavior during unusable trials which has not been reported in prior studies. This information is important for understanding how to mitigate the occurrence of unusable trials in future studies. Aim 2 will collect preliminary data on eye-movement variables which may be indices of word-understanding in minimally verbal autistic children. Due to the heterogeneity of this population and the systematic exclusion of children with minimal verbal skills from previous research on eye-tracking in autism, there is very little empirical evidence on eye-movement variables which may indicate word understanding for autistic children with minimal verbal skills. This research will address a need identified by NIH to develop and evaluate assessments of receptive understanding for autistic children who are minimally verbal/non-speaking (NOT-DC-23-009).