Purpose: To investigate the perception and production of lexical stress and processing of affective prosody in adolescents with high-functioning autism (HFA). We hypothesized preserved processing of lexical and affective prosody but atypical lexical prosody production.
Method: Sixteen children with HFA and 15 typically developing (TD) peers participated in 3 experiments that examined the following: (a) perception of affective prosody (Experiment 1), (b) lexical stress perception (Experiment 2), and (c) lexical stress production (Experiment 3). In Experiment 1, participants labeled sad, happy, and neutral spoken sentences that were low-pass filtered, to eliminate verbal content. In Experiment 2, participants disambiguated word meanings based on lexical stress (HOTdog vs. hot DOG). In Experiment 3, participants produced these words in a sentence completion task. Productions were analyzed with acoustic measures.
Results: Accuracy levels showed no group differences. Participants with HFA could determine affect from filtered sentences and disambiguate words on the basis of lexical stress. They produced appropriately differentiated lexical stress patterns but demonstrated atypically long productions, indicating reduced ability in natural prosody production.
Conclusions: Children with HFA were as capable as their TD peers in receptive tasks of lexical stress and affective prosody. Prosody productions were atypically long, despite accurate differentiation of lexical stress patterns. Future research should use larger samples and spontaneous versus elicited productions.