EBP Compendium: Summary of Systematic Review
Prosody in Autism Spectrum Disorders: A Critical Review
McCann, J., & Peppe, S.
International Journal of Language & Communication Disorders, 38(4), 325-350.
Indicators of Review Quality:
The review addresses a clearly focused question
Criteria for inclusion of studies are provided
Search strategy is described in sufficient detail for replication
Included studies are assessed for study quality
Quality assessments are reproducible
Description: This is a systematic review of the evidence exploring the prosodic characteristics and skills in individuals with autism spectrum disorder.
Question not specifically stated.
Population: People of all ages with autism spectrum disorders (ASD).
Intervention/Assessment: Prosody assessment
Number of Studies Included: 16
Years Included: 1980 - 2002
- Assessment Areas
- Stress production: “Individuals with autism do appear to express stress atypically, with contrastive stress judged problematic in all studies that investigated it. Findings about default stress conflict, with two studies findings problems and two finding none” (p. 338).
- Phrasing and chunking: Overall, findings on prosodic phrasing appear to be contradictory, however these findings are likely to be unreliable. Only one aspect of prosodic phrasing, pauses, were considered. Duration, occurrence of pauses, fundamental frequency change, and final syllable lengthening were not considered. Also, terminology differed between studies.
- Affect: Two studies addressed affect. One noted that individuals on the autism spectrum including high functioning individuals were impaired on a test of affect compared to typical adults and that the impairment did not correlate with verbal or performance IQ. The second study suggested that children with high functioning autism may not have difficulty understanding affective prosody.
- Intonation patterns: Two studies investigated intonation patterns. Results from one study suggested that children with autism showed greater instability and individual variability than typically developing children. The authors of the second study concluded that the ability of children with autism to produce prosodically correct features is a measure of autistic severity.
- Perception of changes in prosody: Results from one study suggest that children with autism are aware of changes in prosody, but the findings were not able to inform on the nature of prosodic understanding for these children.
- Neural processing of prosody:
- Results from one study indicated that “all participants displayed normal P3 responses to all of the stimuli and performed within normal limits for the auditory discrimination component of the task. This suggests that, at least at the biological level, adults with autism are processing prosody in a way similar to typical adults, although findings might be unreliable as the group of participants was small” (p. 346).
- In a second study authors found that “participants demonstrated a pattern of lateralization similar to typical individuals, but the specific regions of activation differed. The children with autism in this study might therefore have been processing prosody in a different way to typical children. This could account for difficulties with understanding prosody, perhaps leading to difficulty using expressive prosody” (p. 346).
Keywords: Autism Spectrum Disorders, Prosody Disorders
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Added to Compendium: March 2012