Pragmatic language, or the use of language in social contexts, is critical to developing meaningful social relationships and is a significant contributor to mental health. Autism spectrum disorder (ASD), fragile X syndrome (FXS) and Down syndrome (DS) are all genetically based neurodevelopmental disabilities characterized by deficits in pragmatic language, although profiles of strengths and weaknesses vary within these populations. Prior work suggests that overlapping features of pragmatic language across ASD and FXS (a monogenic disorder and the most common inherited cause of intellectual disability) may indicate common genetic etiology (i.e., variation in the FMR1 gene). In contrast, males with DS (the most common cause of intellectual disability that is not inherited) present with many strengths relative to these groups despite comparable language and cognitive abilities. These groups also all demonstrate impairments in linguistic (e.g., vocabulary, syntax), cognitive and social-cognitive abilities related to pragmatics in typical development, providing the opportunity to explore relationships between impairments in these domains and pragmatic skills. Therefore, characterizing profiles of pragmatic language development in these populations holds potential for identifying syndrome specific cognitive and linguistic abilities contributing to pragmatic language, as well as identifying possible common genetic etiologies. This dissertation incorporates three manuscripts that aim to characterize pragmatic language in these groups. The Introduction provides a brief background and justification for the research questions addressed by this dissertation. Then, three interrelated manuscripts are included. The first, A Systematic Review of Pragmatic Language in Autism Spectrum Disorder and Fragile X Syndrome reviews cross-population comparisons of pragmatic language in ASD and FXS. The second, A Cross Context, Longitudinal Study of Pragmatic Language Development Across Neurodevelopmental Disabilities, applied standardized measures, detailed hand coding of narrative, and clinical-behavioral ratings of semi-naturalistic conversation in males with ASD-O, FXS-ASD, FXS-O, DS and TD at up to three time points. Finally, the third manuscript, Computational Approaches to Characterizing Language Features in Neurodevelopmental Disabilities, explored the application of computational language tools to narrative and semi-naturalistic conversation samples. Overall, this line of research has critical implications for clarifying developmental and potential genetic mechanisms contributing to pragmatic language impairments across groups, and represents a step in the development of novel language assessment tools.

Creator

• Lee, Michelle

DOI

• https://doi.org/10.21985/n2-a6fy-1q06

Subject

• Clinical psychology

Language

• en

Alternate Identifier

• etdadmin_upload_560496
• http://dissertations.umi.com/northwestern:14026

Keyword

• Development
• Down syndrome
• Language
• Autism Spectrum Disorder
• Fragile X Syndrome

Date created

• 2018-01-01

Resource type

• Dissertation

Rights statement

• In Copyright