Speech planning and monitoring in Parkinson's disease: a speech motor control perspective
Despite doing it almost without effort, speaking is a highly complex task requiring precisely timed and linguistically-driven coordination of the lungs, vocal folds and speech articulators (e.g. lips, tongue). This process, speech motor control, relies on both feedforward (pre-planned movements based on stored movement representations drawn from past experiences) and feedback (monitoring sensory input relative to what is expected) control mechanisms. Research suggests that these mechanisms may be impaired in Parkinson’s disease (PD) patients. However, current findings have resulted from studies with small samples and heterogeneous PD groups.
The central aim of this project is to identify which speech control mechanisms in PD patients are impaired and to what extent by comparing newly-diagnosed PD patients, advanced-stage PD patients, and healthy adults. Specifically, we will investigate how participants cope with feedback perturbations in speech, by measuring both the resulting acoustic speech signal and the underlying speech motor articulation using electromagnetic articulography and ultrasound tongue imaging. To assess whether the potential impairments of the feedback and feedforward system are speech-specific or more general (as PD is a movement disorder), we will also conduct feedback perturbation experiments in non-speech motor movement tasks.
The innovative combination of these methods will enable us to identify whether and how impairments of speech planning and monitoring are related to the progression of PD. Furthermore, the extent to which PD patients cope with feedback perturbations compared to healthy adults may potentially serve as a diagnostic marker for the disease. This would be highly relevant in our aging society.
The PhD project is supervised by prof. dr. Martijn Wieling and dr. Roel Jonkers in collaboration with dr. Aude Noiray from the Laboratory for Oral Language Acquisition (University of Potsdam). The research is funded by the NWO grant PhD in the Humanities and carried out within the Centre for Language and Cognition Groningen in affiliation with the Research School of Behavioural and Cognitive Neurosciences (BCN).