Articulatory evidence for functional coupling of speech and non-speech motor tasks

Benjamin Parrell, Louis Goldstein, Sungbok Lee, and Dani Byrd, Department of Linguistics, University of Southern California

Control of speech production is part of the larger motor control system, and as such can be organized into coordinative structures (or functional synergies) with other motor behaviors, that can then be parameterized as single functional units. The current study explores this phenomenon, expanding previous findings with direct kinematic evidence of speech production. Findings indicate that amplitude of repetitive synchronized speech and manual movements covary systematically across repetitions. In addition, magnitude of the movement of both of these effectors is larger when the participant is instructed to place emphasis on a repetition with one effector, but not the other. Thus, control of speech prosody may modulate a functional synergy that is defined over a wide set of articulatory subcomponents, not just the speech motor system.