Neural and behavioural correlates of speech production in Parkinson's disease

Speech is a complex task requiring highly coordinated movements of a large group of respiratory, laryngeal and articulatory muscles and involves precise integration with auditory and somatosensory feedback to plan and execute speech movements. Speech production deficits in individuals with Parkinson’s disease (PD) include a range of symptoms comprising reduced loudness, monopitch, imprecise articulation, and reduced respiratory control (bradykinesia). These changes can negatively affect individual’s quality of life. These symptoms may be due to brain changes resulting from a general neurological impairment of areas that control and adjust movements based on sensory input. In this research study, we aim to address the question of how behavioural and neural mechanisms of speech motor control and learning are impaired in individuals with PD. To address these questions, we will utilize behavioural paradigm of auditory feedback perturbation to probe speech motor control and learning functions along with the neural paradigm of electroencephalography (EEG) and auditory brainstem response (ABR) recordings that allows us to measure neural activity from different brain areas when participants perform a speech task. The outcome of this research will be used to determine the source of the speech production deficits in PD and to ultimately develop new technologies for assessment and treatment of speech disorders in individuals with PD.