A Systematic Investigation of Phonetic Complexity Effects on Articulatory Motor Performance in Progressive Dysarthria

The long-term goal is to optimize dysarthria assessment by improving the early detection and tracking of articulatory performance in progressive dysarthrias. The short-term goal of the proposed cross-sectional study is to focus on ALS and PD and quantify articulatory kinematic performance as a function of phonetic complexity, which is experimentally manipulated based on theoretical principles of speech motor development. The research strategy is to use 3D electromagnetic articulography to examine phonetic complexity effects of single word stimuli at the articulatory kinematic level in 15 talkers each with preclinical, mild, and moderate dysarthria, relative to 45 controls. The central hypothesis is that as dysarthria severity increases the discrepancy in articulatory performance, indexed by movement speed, distance, coordination, and variability, between people with dysarthria and typical controls will significantly increase at a lower phonetic complexity level.