Evaluation of a reiterant force-impulse task in the tongue.

In the current study characteristics of a lingual force-impulse task were examined. In the task, neurologically normal adults were required to produce sequences of lingual force impulses that were modeled on sequences of syllables produced as reiterant speech. The goal of data analysis was to (a) compare the timing of the reiterant force sequences to the timing of reiterant speech sequences, (b) compare the force magnitudes to expected force variations associated with linguistic stress in the reiterant speech sequences, and (c) compare the reiterant force magnitudes to maximum lingual forces. Results indicated that reiterant force timing is typically slower than reiterant speech timing, that reiterant force magnitudes do not vary systematically as a function of stress variations in the reiterant speech utterances, and that reiterant force magnitudes are typically only a fraction of maximum lingual forces. Results are discussed in terms of the relationship between orofacial, nonspeech motor performance and speech production performance.