Investigation And Assessment Of Mirror Neuron Activity For Rehabilitation Purposes
Year: 2017
Type: dissertation
Abstract: Mirror neurons, discovered on prefrontal cortex and subsequently on \ninferior parietal lobule of macaque monkey, are a class of neurons that \nbecome activated with both performing an action and observing the same \naction. A similar system of neurons also exists in humans. On the basis \nof features of the putative mirror neuron system (MNS) and its role in \naction understanding and internal rehearsal (motor imagery) of actions, \nthis action observation-execution matching system has been proposed as \na new approach for training in the rehabilitation of patients with motor \nimpairment of the upper limb after stroke. \nThis thesis investigates the mu and/or beta frequency band suppression as \nan index of the human mirror neuron system (MNS) in \nElectroencephalography (EEG). Several experimental design and control \nprocedures were applied with the primary objective that the study might \nbe beneficial to motor rehabilitation programs of upper extremities for \nstroke patients. \nv \nIn the first experiment, subjects observed different types of objectdirected \nhand actions in order to explore whether observation of any of \nthese actions may have a relatively strong effect on MNS activity. Here, \nEEG was recorded at electrode locations C3, C4, P3, P4, F7 and F8. The \nresults showed that all conditions were associated with a significant mu \nband (8-12 Hz) desynchronization over the somatosensory cortex. \nFurther investigation of the effect of the visual stimuli on MNS revealed \nthe main effect of video stimuli of hand squeezing soft and hard springs, \nat the frontal channels nearly corresponding to ventral premotor cortex \n(vPMC) area of the brain. The activation of mirror neurons in this area \nduring action observation plays a crucial role in observational learning. \nBased on these results, it was proposed that specific type of visual stimuli \nmay be implemented in the action observation-based treatment of stroke \npatients to have a positive additional impact. \nRecent evidence suggests that motor imagery might be beneficial to \nrecovery of motor functions after stroke. The implemented strategy in \nimagery-based rehabilitation may have a crucial role to optimize the \nimagery performance. In the second experiment, it has been explored if \nprior execution facilitates the subsequent imagery performance when the \nmotor task to be imagined was associated with a symbolic cue. 10 healthy \nparticipants were divided into two groups and performed the execution \nand imagery of a sequential pinch grip task: one group started the \nexperiment by execution of the task (group named GEF) and the other \ngroup performed the imagery session at first stage (group named GIM). \nEvent Related Spectral Perturbations (ERSPs) at mu (8-12 Hz) and beta \n(15-25 Hz) frequency bands from EEG data were extracted for imagery \nand execution conditions of 10 subjects over central, parietal and frontal \nbrain regions. The results showed that both simple execution and imagery \nconditions were associated with a significant (p<0.05) mu and beta band \ndesynchronization over the somatosensory cortex. A significant main \neffect of frequency was found during imagery condition of 10 subjects \nand over all relevant channels. This supplies evidence that mu and beta \nrhythms might have different functional properties for mental rehearsal \nof actions. ERSP data from two experimentally manipulated groups \nshowed that brain activity (desynchronization) for imagery condition was \nslightly higher for group GEF. Significant differences between two groups \nwere found at contralateral parietal and bilateral frontal sides. It was \nconcluded that for a cue-based simple motor task, a prior execution of \nthe motor task might facilitate the subsequent imagery task and frontal \nregions appears to reflect the motor imagery performance. The results \nwill have further implications in imagery-based rehabilitation of patients \nwith stroke. \nIn the last experimental study of this thesis, a fully actuated finger \nexoskeloton robot ExoPinch was utilized to investigate the anticipatory \nvi \neffect of execution on observation. The results showed that the \nobservational condition (with or without anticipation) interacted with \nhemisphere at central channels near somatosensory cortex. Additionally, \nthe response of MNS was explored on the kinetics features of visual \nstimuli. The results revealed an interaction effect of kinetics features and \nhemisphere at frontal channels corresponding nearly to the ventral \npremotor cortex area of the brain. The activation of mirror neurons in \nthis area plays a crucial role in observational learning. Based on the \nresults, it was proposed that specific type of visual stimuli can be \ncombined with the functional abilities of the MNS in the action \nobservation based treatment of hand motor dysfunction of stroke \npatients to have positive functional motor responses.
Author: Gözde Bayer
Language: English
Subfield: Social Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W2765384023