PROJECT SUMMARY Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder associated with motor difficulties in speech production and fine-motor tasks. Assessments of motor impairments, however, can be subjective and miss subtle and specific abnormalities. Therefore, there is a need to develop objective measures for clinicians to assess and understand speech- and fine-motor impairments in individuals with ASD. In addition, recent research suggests that difficulties with speech production, fine-motor, and oculo-motor tasks may contribute to language difficulties in ASD. The purpose of this project is to develop objective measures of speech- and fine-motor coordination in children with ASD, and to characterize the relationship between motor modalities and expressive language in ASD using these measures. We will focus on three speech subsystems: articulatory, laryngeal, and respiratory, as well as handwriting and eye movement. In a pilot study we conducted at the Lurie Center for Autism, we utilized novel coordination features developed in our lab to highlight lower complexity of coordination, or higher coupling, between and within speech subsystems in highly verbal children with ASD as compared to neurotypical controls. The analyses also indicated lower complexity of coordination during handwriting in children with ASD, suggesting there may be similar underlying mechanisms across these motor systems. In the proposed project, we will extend upon these promising results, evaluating measures of motor coordination using low-level features derived from speech, handwriting, and eye movement tasks completed by children with ASD and neurotypical controls. We will employ acoustic-to-articulatory inversion techniques to extract more physiologically accurate vocal tract articulator movements and coordination. Aim 1 uses measures of coordination to characterize the complexity of speech- and fine-motor coordination in children with ASD. We will also determine the features which provide the highest discriminatory ability between children with ASD and neurotypical controls using machine learning models. We expect that identification of patterns of complexity and important discriminatory features will provide a better understanding of the dependencies across and within motor subsystems, which could be used for objective assessment and tracking of motor difficulties in ASD. Aim 2 characterizes the relationship between speech- and fine-motor skills and expressive language ability. We will evaluate correlations and regressions between measures of motor coordination and scores on assessments of expressive language. We believe that motor tasks and features which show high correlations with evaluations of language ability will provide further insight into how motor modalities are associated with language difficulties in ASD. In summary, this proposal aims to quantify and understand speech- and fine-motor coordination challenges in ASD using objective measures of m...