Do children and adults with language impairment recognize prosodic cues?

Purpose: Prosodic cues are used to clarify sentence structure and meaning. Two studies, one of children with specific language impairment (SLI) and one of adults with a history of learning disabilities, were designed to determine whether individuals with poor language skills recognize prosodic cues on par with their normal-language peers. Method: Participants were asked to determine whether low-pass filtered sentences matched unfiltered target sentences. Filtered sentences either matched the target sentence exactly or differed on between 1 and 3 parameters that affected the prosodic profile of the sentences. Results: Children with SLI were significantly poorer than their normal peers in determining whether low-pass filtered sentences matched or were different from unfiltered target sentences. The children's performance, measured in terms of response accuracy, deteriorated as the similarities between filtered and unfiltered sentences increased. Adults revealed a pattern of differential reaction time to sentence pairs that reflected their relative degree of similarity. There was no difference in performance accuracy for adults with a history of language/learning disabilities compared with their peers. Conclusion: Given that prosodic cues are known to assist language processing, the weak prosodic skills of preschool children with SLI may limit the amount of benefit that these children derive from the presence of prosodic cues in spoken language. That the adult sample did not show a similar weakness in this skill may reflect developmental differences, sampling differences, or a combination of both.