PROJECT SUMMARY/ABSTRACT The factors that disrupt the normal acquisition of functional speech in minimally verbal (MV) children with autism (ASD) remain unknown. The proposed study uses computer-based biomechanic assessment to (1) Identify oromotor impairments in children with MV ASD; (2) Determine if the motor deficits in children with MV ASD are specific to the oromotor system or extend globally across motor systems; (3) Determine if the severity of oromotor deficit predicts impairments in communication development when nonverbal IQ is controlled for; and (4) Determine how oromotor development and language ability in children with MV ASD change over time. The scientific premise for this project is that biomechanic-based assessments will yield direct, objective, and highly- replicable information about the oromotor capabilities of children with MV ASD. To accomplish our aims, we will obtain comprehensive profiles of oromotor performance from 60 children with MV ASD, 45 age- and sex-matched verbal children with ASD, and 45 similarly matched TD controls using non-invasive, 3D facial-motion capture technology. We will also obtain clinical measures of speech and language ability, and several selected measure of gross motor function. All measures will be obtained longitudinally every 12 months for three time points. Robust statistical modeling methods will be used to characterize individual patterns of change in oromotor performance and the association between the acquisition of speech motor skills and those in other developmental domains (i.e., language and general-motor). The information obtained from this study will provide the foundational knowledge needed to address ongoing clinical and scientific challenges including improving early detection of autism impairments, predicting communication outcomes, and identifying the neurobiological and genetic mechanisms affecting communication development in this population.