Date of Completion

2-19-2018

Embargo Period

2-17-2028

Major Advisor

Inge-Marie Eigsti, Ph.D.

Associate Advisor

Deborah Fein, Ph.D.

Associate Advisor

Emily Myers, Ph.D.

Field of Study

Psychology

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

Though the structural linguistic abilities of people with autism spectrum disorder (ASD) vary substantially, even people without obvious impairments in communication exhibit subtle syntactic deficits that are not necessarily detected by clinical assessments. Language acquisition is a complex generalization task that requires prolific extension of learned form-to-meaning mappings to novel stimuli. Generalization itself, the process by which abstracted features of past experiences are extended to new instances, is an area of relative weakness in ASD. The current study aimed to determine whether linguistic generalization in particular is an area of weakness for people with ASD, to compare the neural resources engaged for linguistic generalization in people with and without ASD, and to determine the degree to which linguistic generalization is a domain-general process. Seventeen young adults with ASD and 17 well-matched typically developing peers completed two experiments that tested their ability to abstract a principle and generalize it to new stimuli while undergoing functional magnetic resonance imaging. One experiment tapped linguistic generalization, and a nonlinguistic comparison experiment tapped visuospatial generalization. Results showed subtle deficits in task accuracy in the ASD group, and subtle differences in underlying neural mechanisms. Group differences in neural substrates of linguistic generalization related to previously documented differences in language processing in ASD. Performance on linguistic generalization tasks was highly correlated with performance on visuospatial generalization tasks, suggesting domain-generality. This was further supported by substantial overlap in neural resources serving generalization across the two domains. Results are discussed with respect to the implications of a generalization weakness on language development. Clinical implications include the consideration of specific supports for generalization in interventions targeted to high-functioning, highly-verbal adults with ASD.

Available for download on Thursday, February 17, 2028

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