PROJECT SUMMARY/ABSTRACT The vast majority of young children with autism spectrum disorder (ASD) demonstrate severe and persistent delays in language development that negatively impact their ability to form social relationships, succeed in school, and achieve an optimal quality of life. Given the severity of language delays and their lasting impact, many interventions have been developed to improve language skills in children with ASD. A central strategy in such interventions is for adults to modify the way they speak to help children understand and learn from spoken language—for example, by simplifying their utterances, relative to utterance length in adult conversation. However, the field lacks controlled, experimental evidence regarding how linguistic simplification impacts children’s ability to understand and learn from spoken language. This gap in knowledge poses a significant barrier to evidence-based practice and scientific progress. Fortunately, our team has validated and refined the tools needed to address the limitations of prior work. In the proposed study, we adopt the looking- while-listening paradigm to examine real-time effects of utterance simplification on children’s language processing and word learning. As a screen-based task, looking-while-listening has limited behavioral task demands, making it appropriate for children with a wide range of abilities (including those who are minimally verbal). The objective of the proposed project is to determine how linguistic simplification affects language processing and word learning in young children with ASD. Participants will be 104 children with ASD (2 – 4 years old) with a broad range of abilities. Children will complete standardized assessments and looking-while- listening tasks. Based on strong preliminary data, our central hypothesis is that simplification will negatively affect processing and learning. This central hypothesis will be addressed by 3 Specific Aims: 1) Determine how single-word and telegraphic simplification affects language processing in young children with ASD. 2) Determine how single-word and telegraphic simplification affects word learning in young children with ASD. 3) Evaluate child characteristics that may moderate the effects of linguistic simplification on language processing and word learning in young children with ASD. Regardless of the outcome, these results will have a strong impact on theory and clinical practice. Findings will be significant because they will determine how linguistic simplification affects children’s ability to understand and learn from spoken language. This project will also contribute to our long-term goal of systematically evaluating the components (and likely active ingredients) of early language interventions.

Project Narrative The proposed project is consistent with NIDCD’s focus on improving language interventions for young children with autism spectrum disorder (ASD), including those who are minimally verbal. Findings will improve our ability to offer empirically supported clinical recommendations regarding adult linguistic simplification, thereby advancing evidence-based practice and maximizing long-term outcomes in children with ASD.