The link between prosody and language skills in children with specific language impairment (SLI) and/or dyslexia.

BACKGROUND: Children with specific language impairment (SLI) and dyslexia are known to have impairments in various aspects of phonology, which have been claimed to cause their language and literacy impairments. However, 'phonology' encompasses a wide range of skills, and little is known about whether these phonological impairments extend to prosody. AIMS: To investigate certain prosodic abilities of children with SLI and/or dyslexia, to determine whether such children have prosodic impairments, whether they have the same pattern of impairments, and whether prosodic impairments are related to language and literacy deficits. METHODS & PROCEDURES: Six subtests of the Profiling Elements of Prosodic Systems - Child version (PEPS-C) were used to investigate discrimination/comprehension and imitation/production of prosodic forms that were either independent of language or that had one of two linguistic functions: chunking (prosodic boundaries) and focus (contrastive stress). The performance of three groups of 10-14-year-old children with SLI plus dyslexia, SLI, and dyslexia were compared with an age-matched control group and two younger control groups matched for various aspects of language and reading. OUTCOMES & RESULTS: The majority of children with SLI and/or dyslexia performed well on the tasks that tested auditory discrimination and imitation of prosodic forms. However, their ability to use prosody to disambiguate certain linguistic structures was impaired relative to age-matched controls, although these differences disappeared in comparison with language-matched controls. No, or only very weak, links were found between prosody and language and literacy skills in children with SLI and/or dyslexia. CONCLUSIONS & IMPLICATIONS: Children with SLI and/or dyslexia aged 10-14 years show an impaired ability to disambiguate linguistic structures for which prosody is required. However, they are able on the whole to discriminate and imitate the actual prosodic structures themselves, without reference to linguistic meaning. While the interaction between prosody and other components of language such as syntax and pragmatics is problematic for children with SLI and/or dyslexia, prosody itself does not appear to be a core impairment.

Derivational morphology in children with grammatical-specific language impairment.

Although it is well-established that children with Specific Language Impairment characteristically optionally inflect forms that require tense and agreement marking, their abilities with regards to derivational suffixation are less well understood. In this paper we provide evidence from children with Grammatical-Specific Language Impairment (G-SLI) that derivational suffixes, unlike tense and agreement suffixes, are not omitted in elicitation tasks. We investigate two types of derivation - comparative/superlative formation and adjective-from-noun formation - and reveal that G-SLI children supply these suffixes at high rates, equivalent to their language matched peers. Moreover, increasing the phonological or morphological complexity of the stimulus does not trigger suffix omission, although it results in non-target forms that are not characteristic of typically developing children. We discuss what these results reveal about the nature of the deficit in G-SLI within the context of three hypotheses of SLI: the Extended Optional Infinitive, Implicit Rule and Computational Grammatical Complexity Hypotheses.