Abstract/Summary

Individuals with autism spectrum disorder (ASD) often exhibit atypical imitation. However, few studies have identified clear quantitative characteristics of vocal imitation in ASD. This study investigated imitation of speech and song in English-speaking individuals with and without ASD and its modulation by age. Participants consisted of 25 autistic children and 19 autistic adults, who were compared to 25 children and 19 adults with typical development matched on age, gender, musical training, and cognitive abilities. The task required participants to imitate speech and song stimuli with varying pitch and duration patterns. Acoustic analyses of the imitation performance suggested that individuals with ASD were worse than controls on absolute pitch and duration matching for both speech and song imitation, although they performed as well as controls on relative pitch and duration matching. Furthermore, the two groups produced similar numbers of pitch contour errors, pitch interval errors and time errors. Across both groups, sung pitch was imitated more accurately than spoken pitch, whereas spoken duration was imitated more accurately than sung duration. Whereas children imitated spoken pitch more accurately than adults when it came to speech stimuli, age showed no significant relationship to song imitation. These results reveal a vocal imitation deficit across speech and music domains in ASD that is specific to absolute pitch and duration matching. This finding provides evidence for shared mechanisms between speech and song imitation, which involves independent implementation of relative versus absolute features.