Variability of tongue muscle activities and its implications
Kiyoshi Honda, Thomas E. Baer, Peter J. Alfonso · The Journal of the Acoustical Society of America · 1982
We have collected a large amount of simultanenusly recorded tongue EMG data [P. J. Alfonso et al., J. Acoust. Soc. Am. Suppl. I 71, S54 (1982)]. The study reported here is based on these data and further investigates the coordination of the tongue muscles in static and dynamic conditions during vowel production. We examine the variability of the data associated with F0 change. We also examine the intercorrelations among these muscles in terms of token-to-token EMG variability. Since the tongue consists of a network of muscles, an articulatory gesture uses coordinated activities of multiple muscles. In repetitions of tokens, relative activities of the muscles vary with each other. These variabilities provide a view on the organization of muscular control of the tongue. The preliminary analysis demonstrated that when the genioglossus showed increased activity during high-pitched /i/, the antagonistic muscles (the hyoglossus and the styloglossus) showed some increased activities while the agonistic muscles (the mylohyoid and the geniohyoid) sometimes showed relatively low activities. This implies that these variabilities are regulated in order to maintain the noncompressive approximation of the tongue. [Research supported by NINCDS.]