A multidimensional study on articulation deficits in Parkinsons disease - PROJECT ABSTRACT
Dysarthria is a motor speech disorder that affects individuals with a variety of etiologies.
Parkinson’s disease (PD) alone affects nearly one million individuals in the U.S., with dysarthria
developing in approximately 90% of these individuals within the first two years of onset. The
dysarthria associated with PD is characterized by reduced movement, which has been supported
by findings of reduced lip, tongue, and jaw movement in speakers with PD. However, it remains
unclear if hypokinetic dysarthria causes a global reduction across all articulators, or if specific
articulators are disproportionally affected by the disease. Further, we do not fully understand the
factors contributing to speech intelligibility. Specifically, little is known about the articulatory-
kinematic correlates of speech intelligibility. This missing link is vital to understand, as articulation
deficits are a universal characteristic of dysarthria, regardless of etiology. The proposed study
provides a linked investigation of kinematic, acoustic, and perceptual characteristics in speakers
with PD and neurologically healthy speakers. This research aims to (1) examine the perceptual,
acoustic, and articulator-specific movement deficits in speakers with PD and (2) understand the
relationship between articulatory movement and measures of speech perception. Specific Aim 1
will examine the group differences between speakers with PD and neurologically healthy
speakers using perceptual, acoustic, and articulator-specific kinematic measures. We
hypothesize the perceptual, acoustic, and tongue-related kinematic measures will differentiate
individuals with PD from neurologically healthy speakers. Specific Aim 2 will model speech
intelligibility (Specific Aim 2a) and ratings of articulatory precision (Specific Aim 2b) using selected
acoustic and kinematic measurements. We hypothesize that the acoustic measures will be
stronger predictors of speech intelligibility than the kinematic measures, as they are both derived
from the speech signal. Further, we hypothesize the selected kinematic measures may
demonstrate a stronger relationship to articulation ratings than speech intelligibility. This study is
a requisite step towards our long-term goal of advancing dysarthria management strategies. The
primary outcome will be explanatory models that identify acoustic and articulatory correlates of
speech intelligibility and articulatory precision. This study has important implications for
developing articulator-specific dysarthria management strategies to supplement universal
dysarthria management strategies.
