Speech versus nonspeech: different tasks, different neural organization.

This article reviews the extant studies of the relation of oromotor nonspeech activities to speech production. The relevancy of nonspeech oral motor behaviors to speech motor performance in assessment and treatment is challenged on several grounds. First, contemporary motor theory suggests that movement control is task specific. In other words, it is tied to the unique goals, sources of information, and characteristics of varying motor acts. Documented differences in movement characteristics for speech production versus nonspeech oral motor tasks support this claim. Second, advantages of training nonspeech oral motor tasks versus training speech production are not supported by current principles of motor learning and neural plasticity. Empirical data supports experience-specific training. Finally, functional imaging studies document differences in activation patterns for speech compared with nonspeech oral motor tasks in neurologically healthy individuals.