The objectives of this K23 study are to identify underlying dysfunction in vocal sensorimotor control and its relation to clinical voice abnormalities and cognitive rigidity in individuals with Autism Spectrum Disorder (ASD). The rationale for this study is based upon well-established evidence of dysfunction in other areas of functioning (e.g., auditory processing, motor control) that are integral to speech and voice production, but have never been specifically examined in the vocal system in ASD. This poor understanding of the etiology of voice dysfunction in ASD limits our ability to develop treatment or preventative interventions that target the source of the problem. Thus, this project aims to dissect and characterize the specific mechanisms of abnormalities in the pitch, intensity, and nasality of voice in individuals with ASD. Specifically, this proposal will be the first to investigate neural (MEG) and psychophysical measures of feedforward and feedback control of voice in conjunction with neuropsychological measures of cognitive processes that may be associated with voice abnormalities in children with ASD. Thus, the knowledge to be gained by evaluating these evidence-driven hypotheses will not only advance our understanding of the broader feedforward and feedback control deficits in individuals with ASD, but they will also enrich our understanding of the dysfunctional processes underlying their voice abnormalities, a symptom domain for which advances in treatment have been particularly inadequate relative to need. These study aims also will provide the candidate with a foundation for implementing future independent brain imaging studies of vocalization in ASD through provision of additional training in basic speech neuroscience, neuroimaging, and functional voice pathology of individuals with ASD. Successful completion of the research and training activities in this project will inform the development of an R01 proposal focused on investigating the ability to use sensory feedback manipulation to remediate voice abnormalities in individuals with ASD.
At least half of individuals with ASD present with atypical acoustic patterns of vocalization that persist even after other aspects of communication, such as verbal language, improve6,13. These voice abnormalities are not only impairing to communication, but they also attract teasing, bullying, and social rejection6,11,12, and contribute to the ongoing deficits in social interaction, communication, and social development that define ASD8?10. Despite their interference with communication of nonverbal vocal cues and other negative social consequences, the causes of these symptoms remain unknown and have been sparsely investigated. This study will be the first to examine these well-documented voice abnormalities in ASD in relation to sensorimotor control and deficits in mental flexibility. The information gained from this study may be key to development of targeted interventions to remediate voice abnormalities.
