Contributions of Motor Control to the Acquisition of Prosodic Structure
The ability to produce stress patterns to achieve different linguistic goals is a major developmental task for young children. The production of such stress variation is particularly problematic for children with specific language impairment (SLI). These children are characterized by their language deficits, but motor skill has also been found to be below expected levels. The major approach of the research presented is to integrate methodologies from motor control and linguistics to understand both normal and disordered prosodic development. Data from three studies will be incorporated into a discussion of how motor propensities and language goals interact in the developmental process. In all of these studies, kinematic recordings of oral movements were collected in concert with an audio recording (for the language level analysis). Children produced stress patterns that contained elements that are problematic to acquire, such as weak syllables of content words and grammatical markers. All of the data suggest that children, both normally developing and SLI, rely on basic motor propensities for the production of early developing prosodic targets. Further, children with SLI show deficits in their control of temporal and spatial aspects of speech motor output.