Abstract:
The ability of a 2-D biomechanical model of the tongue to reproduce kinematic properties of human tongue movements in V-V transitions is assessed. The model consists of a finite elements description, and simulates the main agonist/antagonist muscle pairs (posterior Genioglossus/Hyoglossus and anterior Genioglossus/Styloglossus). The external geometrical shape of the model has been adapted from X-ray data, to fit the tongue contours of a French native speaker. Movement data were collected on this speaker with an electromagnetometer (Carstens Electronics, AG100) for the tokens [i-a], [i-e], [i-(cursive beta)], [a-i], [(cursive beta)-i], [e-i], [i-e-(cursive beta)-a], [a-(cursive beta)-e-i], [y-(oe ligature)], [y-o], [y-u], [u-y], [o-y], [(oe ligature)-y], [y-(oe ligature)-o-u], [u-o-(oe ligature)-y]. For each token, the speaker was asked to keep the lip shape constant. The jaw was held in a constant position with a small bite-block (5 mm). For the simulations, according to Feldman's equilibrium-point hypothesis [A. Feldman, ``Once more Equilibrium-Point Hypothesis for motor control,'' J. Motor Behav. 18 (1986)], movement was produced by shifting, at a constant rate, the mechanical equilibrium of the motor system from one equilibrium-target position to another one. Simulations are assessed in the kinematic and acoustic spaces. [Work supported by the European Union.]