Fragile X syndrome (FXS) is the leading single-gene disorder associated with a diagnosis of autism. This research compared language prosody of boys with autism spectrum disorder (ASD) only (ASD-O), FXS with ASD (FXS-ASD), FXS only (FXS-O), and typical development (TD) to identify precise autism phenotypes that could be linked with the Fragile X Mental Retardation-1 gene (FMR1). The specific aims were to identify profiles of language prosody that overlap in autism and FXS or are specific to autism, to determine concordance between rater judgments and objective quantitative indices of prosody, and to determine whether social cognition accounts for anticipated group differences in prosody. The boys' language in imitated sentences and conversational speech was examined for prosody using both acoustic measures (F0 variation, utterance final F0 drop, actual articulation rate, and the pairwise variability index [PVI]) and perceptual measures (listener judgments of phrasing, rate, and stress from The Prosody-Voice Screening Profile [PVSP]). In addition, a direct magnitude estimation (DME) study was used to assess perceived peculiarity of speech. Relationships between judgments of prosodic peculiarity and specific aspects of prosody, as well as the relationship between social cognition (theory of mind) and prosody, was examined. As well as furthering our understanding of the association between autism and FMR1, determining the differences and overlap in prosodic profiles of boys with FXS and ASD using both rater judgments and objective measures has important clinical implications.
National Institute on Deafness and Other Communication Disorders
09/01/2010 to 08/31/2013