Neural and motor responses to mental and physical fatigue
department or school: Health and Social Development, Faculty of (Okanagan)
department or school: Health and Exercise Sciences, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Magnuson, Justine
issued: 2023-01-25T17:24:58Z
issued: 2023
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: The overall aim of my dissertation was to assess cortical and neuromuscular responses to both mental and physical fatigue. My first two studies showed that mental fatigue, induced by either a prolonged cognitively demanding task or sleep deprivation, resulted in slowed ongoing neural activity, less efficient evoked cortical responses, and worse accuracy on a complex reaching task. Study #1 also showed that after acute mental fatigue is induced, motor task performance recovers by ~40 minutes post-task, whereas slowed ongoing cortical activity and increased ratings of fatigue are still present until at least 60 minutes post-task, suggesting a different time course of recovery for behavioural and cortical responses. Study #2 showed that, in addition to slowed and impaired inhibitory control with sleep deprivation, task performance during an emotional inhibitory control task was even worse, suggesting interference of emotion processing on response inhibition. Study #3 assessed how two types of fatiguing submaximal contractions (matched-torque vs. matched-electromyographic activity, EMG) affected voluntary activation (VA), corticomuscular and intermuscular coherence, and motor unit discharge rates. I found higher coherence, worse VA, and increased motor unit discharge rates in response to the matched-torque task; however, during the matched-EMG task, when motoneuron pool output was maintained, VA and coherence scores were unchanged and motor unit discharge rates decreased. This suggests different compensatory strategies to maintain task performance during a matched-torque vs. matched-EMG fatiguing protocol. Lastly, given the limited understanding of antagonist motor unit behaviour, study #4 aimed to examine the recruitment patterns of motor units when acting as an agonist vs. antagonist. Surprisingly, I found no antagonist motor unit recruitment in most participants during ramped isometric contractions to MVC, despite appreciable surface-EMG activity. This study showed t…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/83752
note: Neural and motor responses to mental and physical fatigue by Justine Magnuson M.Sc., Simon Fraser University, 2018 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE COLLEGE OF GRADUATE STUDIES (Kinesiology) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) January 2023 © Justine Magnuson, 2023 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: Neural and motor responses to mental and physical fatigue submitted by Justine Magnuson in partial fulfillment of the requirements of the degree of Doctor of Philosophy. Dr. Chris McNeil, School of Health and Exercise Sciences Supervisor Dr. Brian Dalton, School of Health and Exercise Sciences Supervisory Committee Member Dr. Paul Van Donkelaar, School of Health and Exercise Sciences Supervisory Committee Member Dr. Sarah Kraeutner, Irving K. Barber Faculty of Arts and Social Sciences University Examiner Dr. Anita Christie, Western University External Examiner iii Abstract The overall aim of my dissertation was to assess cortical and neuromuscular responses to both mental and physical fatigue. My first two studies showed that mental fatigue, induced by either a prolonged cognitively demanding task or sleep deprivation, resulted in slowed ongoing neural activity, less efficient evoked cortical responses, and worse accuracy on a complex reaching task. Study #1 also showed that after acute mental fatigue is induced, motor task performance recovers by ~40 minutes post-task, whereas slowed ongoing cortical activity and increased ratings of fatigue are still present until at least 60 minutes post-task, suggesting a different time course of recovery for behavioural and cortical responses. Study #2 showed that, in addition to slowed and impaired inhibitory control with sleep deprivation, task performance during an emotional inhibitory control task was even worse, suggesting inter…
has type: Thesis/Dissertation
date issued: 2018-05
is shown at: 10.14288/1.0423558
language: eng
degree discipline: Kinesiology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: McNeil, Chris
type: Text
identifier URI: http://hdl.handle.net/2429/83752