Functionality and Perceived Atypicality of Expressive Prosody in Children with Autism Spectrum Disorders

People with autism are perceived to have ‘odd’ prosody, but is it malfunctioning? A new prosody test assesses the functionality of prosody in four aspects of speech (phrasing, affect, turn-end and focus) by tasks that elicit utterances in which prosody alone conveys the meaning. The test was used with 100 typically-developing children (TD), 39 with Asperger's syndrome (AspS) and 31 with high-functioning autism (HFA). In results, HFA<TD on all six tasks, HFA<AspS on four, and AspS<TD on one. In perception experiments, judges rated the atypicality of the prosody in samples of conversation from participants in each of the three groups. Correlation between the judges’ ratings was high, and ANOVAs showed differences between groups similar to those found in the test results. The ratings correlated significantly (mainly at the 0.01 level) with the test’s output scores. The findings support the ecological validity of the test for use as a clinical assessment tool.