Date of Award

12-2014

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Program

Speech and Hearing Science

Research Advisor

Tim Saltuklaroglu, Ph.D.

Committee

John Boughter, Ph.D. Ashley Harkrider, Ph.D. Kristin King, Ph.D.

Abstract

Similar to other complex sequences of muscle activity, swallowing relies heavily upon ‘sensorimotor integration.’ It is well known that the premotor cortex and primary sensorimotor cortices provide critical sensorimotor contributions that help control the strength and timing of swallowing muscle effectors. However, the temporal dynamics of sensorimotor integration remains unclear, even when performed normally without neurological compromise. Recent advances in EEG analysis blind source separation techniques via independent component analysis offer a novel and exciting opportunity to measure cortical sensorimotor activity in realtime during swallowing, concurrently with muscle activity during swallow initiation. In the current study, mu components were identified, with characteristic alpha (~10 Hz) and beta (~20 Hz) frequency bands. Spectral power within these frequency bands are known to index somatosensory and motor activity, respectively. Twenty-five adult participants produced swallowing and tongue tapping (motor control) tasks. Additionally they were asked to watch a video depicting swallowing and a scrambled kaleidoscope (perceptual control) version of this same video. Independent component analysis of raw EEG signals identified bilateral clusters of mu components, maximally localized to the premotor cortex (BA6) in 19 participants during the production and the perception tasks. Event related spectral perturbation (ERSP) analysis was used to identify spectral power within alpha and beta peaks of the mu cluster across time. Alpha and beta event-related desynchronization (ERD), indicative of somatosensory and motor activity, was revealed for both tongue tapping and swallowing beginning at ~500 ms following a visual cue to “go.” However, the patterns of ERD are stronger (pFDR

DOI

10.21007/etd.cghs.2014.0060