Mapping Development Change in Hypersensitivity to Pitch in Children, Adolescents, and Adults with ASD

Background: Whilst enhanced pitch perception has been reported in a large number of studies of individuals with ASD (Bonnel et al., 2003, 2010; Heaton, 2003, 2005; Heaton, Hermelin, & Pring, 1998, 1999; Heaton, Hudry, Ludlow, & Hill, 2008; Heaton, Williams, Cummins, & Happé, 2008; Jones et al., 2009; Mottron, Peretz, & Menard, 2000; O’Riordan & Passetti, 2006) little is known about its behavioural consequences and the extent that it may change over time. Previous research carried out with children with ASD has revealed enhanced sensitivity to the psychoacoustic properties of speech but the extent that this is characteristic in adults has yet to be investigated. Objectives: The present study aimed to replicate earlier findings of superior pitch discrimination across speech and non-speech stimuli in children with ASD within groups of high-functioning adolescents and adults with ASD. A second aim of the study was to examine the cognitive, clinical, and behavioural correlates associated with enhanced pitch perception in the adult group. Methods: The trajectory analysis was carried out on groups of children, adolescents and adults with high-functioning ASD and age and intelligence matched typically developing controls. For the second analysis, cognitive assessments as well as self-report questionnaires were used to assess IQ, communication difficulties, and sensory processing abnormalities associated with superior pitch discrimination in high functioning adults with ASD and controls. Results: The findings showed that whilst levels of discrimination performance did not differ across the child, adolescent and adult groups with ASD, significant increases were observed across all time points in typically developing comparison groups. Correlations carried out on the discrimination data and background data for the adults revealed associations between task performance and working memory scores and autistic symptomatology for the ASD but not the control group Conclusions: The results suggest that the developmental trajectory of pitch discrimination differs in typical development and ASD and that unique associations between pitch discrimination and core features of autism and working memory are characteristic in high-functioning adults with ASD.