| This project investigates the coordination of speech movements starting from the "non-linear dynamic theory" (NLD). In this approach gestures, not sounds, form the primitive units of speech. The main goal of this research project is to find evidence that the kinematic characteristics of movements that are generated for a specific speech task, for example, lip closing, are an emergent property of constraints on the degrees of freedom in motor control that are based on a functional coupling between the individual articulator in the form of a coordinative structure or gesture. In a number of experiments, in which movement velocities and cognitive/linguistic demands are manipulated, hypotheses on normal and pathological speech production are tested. In this research kinematic information on lip, jaw, and tongue movements is gathered using the Electromagnetic Midsagittal Articulography (EMMA) methods. Hypotheses derived from NLD on speech development and the role of various feedback systems were tested in normal children and children with speech and hearing disorders. |
