NONSPEECH v. SPEECH
The idea that nonspeech movements (e.g. moving the tongue tip behind the alveolar ridge, spreading and rounding the lips) could be used to improve speech dates back at least to Sapir (1921). This idea basically went unchallenged until experimental evidence did not support it (e.g. Moore & Ruark, 1996).
The cine film shown below is from Miller and Hardy (1962), and is discussed in Hardy (1965). The 12 year old girl with cerebral palsy first was asked to move the tongue behind the alveolar ridge. Then, she was asked to repeat the syllable [da]. In the nonspeech task she showed extraneous movements of the tongue, with apparent struggle, and could not complete the task. When repeating [da], rapid and consecutive movements of the tongue tip were shown to touch the alveolar ridge. However, the tongue elevation received an assist with upward movements of the jaw during the first part of this segment. More separation of the tongue tip from the jaw is seen in the latter part of this segment. When saying “Please buy me that cute little dog,” there are instances where the tongue tip is clearly elevated without jaw assistance.
This represents a clear dissociation of tongue control for nonspeech and speech movements. Implicitly, nonspeech and speech movements have separate neural mechanisms, and the practice of one does not facilitate the function of the other.
More recent reviews of this topic and the literature are found in Lof and Watson (2008) and Bunton (2009)
June 14, 2012
Click here for the video.
Bunton, K. (2009). Speech versus Nonspeech: Different Tasks, Different Neural Organization. Seminars in Speech and Language. 29(4): 267ﾖ275.
Hardy, J. (1965). Research in speech problems associated with cerebral palsy and implications for the young cerebral palsied child. Speech and Language Therapy with the Cerebral Palsied Child (W. Daley, Ed). Catholic University of America Press: Washington, DC.
Lof , G. and Watson, M. (2008) A Nationwide Survey of Nonspeech Oral Motor Exercise Use: Implications for Evidence-Based Practice. Lang Speech Hear Serv Schools, 39:392–407.
Miller, J. and Hardy, J. (1962). Considerations in evaluating dysarthria. Paper presented to the annual convention of the American Speech and Hearing Association. New York City, NY (1962).
Moore, C. and Ruark, J. (1996). Does speech emerge from earlier appearing oral motor behaviors? J Speech Hear Res. (5):1034-47.
Sapir, E. (1921). Language: An Introduction to the Study of Speech. Harcourt, Brace: New York.