Purpose: People with high-functioning autism (HFA) have qualitative differences in facial expression and prosody production, which are rarely systematically quantified. The authors' goals were to qualitatively and quantitatively analyze prosody and facial expression productions in children and adolescents with HFA.
Method: Participants were 22 male children and adolescents with HFA and 18 typically developing (TD) controls (17 males, 1 female). The authors used a story retelling task to elicit emotionally laden narratives, which were analyzed through the use of acoustic measures and perceptual codes. Naïve listeners coded all productions for emotion type, degree of expressiveness, and awkwardness.
Results: The group with HFA was not significantly different in accuracy or expressiveness of facial productions, but was significantly more awkward than the TD group. Participants with HFA were significantly more expressive in their vocal productions, with a trend for greater awkwardness. Severity of social communication impairment, as captured by the Autism Diagnostic Observation Schedule (ADOS; Lord, Rutter, DiLavore, & Risi, 1999), was correlated with greater vocal and facial awkwardness.
Conclusions: Facial and vocal expressions of participants with HFA were as recognizable as those of their TD peers but were qualitatively different, particularly when listeners coded samples with intact dynamic properties. These preliminary data show qualitative differences in nonverbal communication that may have significant negative impact on the social communication success of children and adolescents with HFA.
Keywords: autism; facial expressions; production; prosody; social communication.