Dissertations / Theses on the topic 'Motor imagery'
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Hovington, Cindy. "Motor imagery : does strategy matter?" Thesis, Kingston, Ont. : [s.n.], 2008. http://hdl.handle.net/1974/1369.
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Bovend'Eerdt, Thamar J. H. "Motor Imagery in Neurological Rehabilitation." Thesis, Oxford Brookes University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520927.
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BONASSI, GAIA. "Motor imagery and motor illusion: from plasticity to a translational approach." Doctoral thesis, Università degli studi di Genova, 2018. http://hdl.handle.net/11567/929823.
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Williams, Jacqueline Louise, and jacqueline williams@mcri edu au. "Motor imagery and developmental coordination disorder (DCD)." RMIT University. Health Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080617.141139.
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Developmental Coordination Disorder (DCD) is characterised by impairments to motor control and learning, the cause of which remains unclear. Recently, researchers have used cognitive neuroscientific approaches to explore the basis of poor coordination in children, with one hypothesis suggesting that an internal modelling deficit (IMD) is one of the underlying causes of DCD. The aim of this thesis was to further test the IMD hypothesis using a motor imagery paradigm - the mental rotation of hands. Versions of this task were used in all studies to assess motor imagery ability, with an additional whole-body task used in Studies 2 and 3. Further, an alphanumeric rotation task was used in Studies 1 and 2 to assess visual imagery ability. Studies 1 and 2 provided varying levels of support for the IMD hypothesis. In Study 1, only a subgroup of DCD children performed differently from other children in the study on the hand tasks, but tighter task constraints in Study 2 led to overall group differences between DCD and controls in terms of accuracy. The DCD group were also significantly less accurate than controls in the whole-body task, but there were no group differences in either Study 1 or 2 on the visual imagery task. Interestingly, in Study 2, there was an indication that children with severe levels of motor impairment were less accurate than children with less severe motor impairment, suggesting that motor impairment level could play a role in the severity of motor imagery deficits. Study 3 was designed to explore the impact of motor impairment severity on motor imagery ability further. The results confirmed that children with severe DCD had greater motor imagery impairment than children with mild DCD - children with severe DCD performed less accurately than both controls and those with mild DCD in the hand task with instructions and the controls in the whole-body task. Further, those children with mild DCD were able to respond somewhat to motor imagery instructions, whereas those with severe DCD were not. This study provided support to the IMD hypothesis, though the deficit was shown to be dependent on a number of factors. Chapter 5 presents a reasoned account of these various findings and their implications are discussed. It is concluded that motor imagery deficits are evident in many children with DCD, but more so in children with severe motor impairment. A general imagery deficit was ruled out based on the findings of Studies 1 and 2 which showed that visual imagery processes appear intact in children with DCD. Taken together with previous imagery and IMD studies, and related research on feedforward control in DCD, it is concluded that the deficits in motor imagery observed in this thesis are consistent with the hypothesis that an IMD is one likely causal factor in the disorder, particularly in more severe DCD. The observation of differing response patterns between children with mild and severe forms of DCD has important implications for developing a theory of DCD and for remediation.
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Schuster, Corina. "Motor imagery techniques applied in stroke rehabilitation." Thesis, Oxford Brookes University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.579510.
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Background: Motor imagery (MI) has been shown to be beneficial if added to physical practice. It remained unclear, whether M I is effective in patients after stroke, whether MI techniques differ across disciplines, and whether MI can be applied to complex motor tasks (MTs) in patients after stroke. Methods and results: Two systematic reviews were conducted: firstly, to evaluate evidence of MI interventions. Four randomised controlled trials (RCTs) confirmed MI efficacy in patients after stroke if added to therapy. Secondly, characteristics of successful MI training sessions in different disciplines were reviewed. Totally 141 MI interventions were identified in education, medicine, music, psychology, and sports. Information describing 17 MI training elements and 7 temporal parameters were identified and compared. Prior to conducting a pilot RCT, two questionnaires to assess MI ability (KVIQ, Imaprax) were translated with associated validity and reliability testing. The single blinded pilot RCT compared two MI approaches: embedded (n=13) vs. added (N=13) MI vs. a control group (N=14) in patients after stroke. Primary outcome measure was time to perform a complex MT. Results revealed a significant change for all three groups from pre- to post-intervention but no group differences. A qualitative study evaluated MI experiences in patients from experimental groups using semi-structured interviews. Results showed that answers matched to MI framework questions where, when, what, why, and how to use imagery. Conclusions and contributions: MI is still under-researched in stroke rehabilitation. Conducted research showed that MI was beneficial if added to therapy and MI techniques varied across disciplines. Embedded and added MI supported patients similarly and could be applied to a complex MT. MI appeared spontaneously in patients after stroke and was used to practice simple movements. Furthermore, this thesis proposed steps towards consistent term usage and detailed MI intervention reporting, which is lacking in current Ml literature.
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Bialko, Christopher Stephen. "The Effects of Practice and Load on Actual and Imagined Action." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1242884385.
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RAMOS, ALIMED CELECIA. "MULTIPLE CLASSIFIER SYSTEM FOR MOTOR IMAGERY TASK CLASSIFICATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=30903@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Interfaces Cérebro Computador (BCIs) são sistemas artificiais que permitem a interação entre a pessoa e seu ambiente empregando a tradução de sinais elétricos cerebrais como controle para qualquer dispositivo externo. Um Sistema de neuroreabilitação baseado em EEG pode combinar portabilidade e baixo custo com boa resolução temporal e nenhum risco para a vida do usuário. Este sistema pode estimular a plasticidade cerebral, desde que ofereça confiabilidade no reconhecimento das tarefas de imaginação motora realizadas pelo usuário. Portanto, o objetivo deste trabalho é o projeto de um sistema de aprendizado de máquinas que, baseado no sinal de EEG de somente dois eletrodos, C3 e C4, consiga classificar tarefas de imaginação motora com alta acurácia, robustez às variações do sinal entre experimentos e entre sujeitos, e tempo de processamento razoável. O sistema de aprendizado de máquina proposto é composto de quatro etapas principais: pré-processamento, extração de atributos, seleção de atributos, e classificação. O pré-processamento e extração de atributos são implementados mediante a extração de atributos estatísticos, de potência e de fase das sub-bandas de frequência obtidas utilizando a Wavelet Packet Decomposition. Já a seleção de atributos é efetuada por um Algoritmo Genético e o modelo de classificação é constituído por um Sistema de Múltiplos Classificadores, composto por diferentes classificadores, e combinados por uma rede neural Multi-Layer Perceptron. O sistema foi testado em seis sujeitos de bases de dados obtidas das Competições de BCIs e comparados com trabalhos benchmark da literatura, superando os resultados dos outros métodos. Adicionalmente, um sistema real de BCI para neurorehabilitação foi projetado, desenvolvido e testado, produzindo também bons resultados.
Brain Computer Interfaces (BCIs) are artificial systems that allow the interaction between a person and their environment using the translated brain electrical signals to control any external device. An EEG neurorehabilitation system can combine portability and affordability with good temporal resolution and no health risks to the user. This system can stimulate the brain plasticity, provided that the system offers reliability on the recognition of the motor imagery (MI) tasks performed by the user. Therefore, the aim of this work is the design of a machine learning system that, based on the EEG signal from only C3 and C4 electrodes, can classify MI tasks with high accuracy, robustness to trial and inter-subject signal variations, and reasonable processing time. The proposed machine learning system has four main stages: preprocessing, feature extraction, feature selection, and classification. The preprocessing and feature extraction are implemented by the extraction of statistical, power and phase features of the frequency sub-bands obtained by the Wavelet Packet Decomposition. The feature selection process is effectuated by a Genetic Algorithm and the classifier model is constituted by a Multiple Classifier System composed by different classifiers and combined by a Multilayer Perceptron Neural Network as meta-classifier. The system is tested on six subjects from datasets offered by the BCIs Competitions and compared with benchmark works founded in the literature, outperforming the other methods. In addition, a real BCI system for neurorehabilitation is designed and tested, producing good results as well.
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White, Alison Elizabeth. "Imagery and sport performance." Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320414.
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Bolles, Gina. "An Exploratory study : the intersection of imagery ability, imagery use, and learning style /." Connect to title online (Scholars' Bank), 2008. http://hdl.handle.net/1794/7478.
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Ammar, Diala Fouad. "The role (relationship) of visual and motor imagery in estimating reach." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/5992.
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The primary intent of this study was to explore fundamental questions about the role and relationship between motor (MI) and visual (VI) imagery within the context of estimating reach. Experiment 1 examined and compared VI and MI tasks under matched environmental conditions with the intent to explore the distinction and cooperation of the visual and motor systems in representing actions. The design of this experiment included an interference paradigm modified from Stevens (2005) in which six blocks of trials (conditions) were used: MI, VI, MI with visual interference, MI with motor interference, VI with motor interference, and VI with visual interference. Results indicated that MI was significantly more accurate than VI in regard to total error, distribution of error and mean bias (p <= .05). Significant increases in the number of errors and estimation bias were found when the modalities for the imagined task and the interference task were matched. The data showed that motor tasks interfered with the ability to MI, whereas visual tasks interfered with the ability to VI. Experiment 2 included a response-delay paradigm modified from Bradshaw and Watt (2002) in which eight blocks of trials were used: MI and VI conditions with no-delay and delays of 1-, 2- and 4 s. Overall, this experiment demonstrated that response-delay influenced accuracy of the MI (visuomotor) task, but not the VI (perceptual) task. That is, after a 4s delay, error in MI increased significantly. Interestingly, these results may indicate a crucial temporal constraint for the representation of distance, isolated in the visuomotor system. In view of both experiments, the findings are consistent with the notion of a distinction between vision for perception (VI) and vision for action (MI) as advanced by Goodale, Westwood & Milner (2004). In conclusion, VI seems to delineate relevant spatial parameters within the environment and then transfer the information to MI. At this point, information is computed in terms of biomechanical possibilities for a certain movement. In summary, just as perception and action are firmly linked, so too are MI and VI.
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Lovell, G. P. "The movement mental imagery ability and acquisition rate relationship." Thesis, Manchester Metropolitan University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246261.
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Wright, Caroline Joy. "The effect of PETTLEP-based imagery interventions on motor performance." Thesis, University of Liverpool, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490914.
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This series of studies investigated the effectiveness of the PETTLEP model across a variety of tasks. In the first two studies, interventions arising from this model were compared to traditional imagery interventions and physical practice. Study 1 compared a six-week intervention of PETTLEP imagery, traditional imagery, physical practice and an intervention combining PETTLEP imagery and physical practice for strength training. Analysis indicated that the PETTLEP combination group, PETTLEP imagery group and physical practice group improved significantly from pre-test to post-test, whereas the traditional imagery group and control group did not. Study 2 compared the effects of PETTLEP imagery, traditional imagery and physical practice interventions on performance of a computer-game. Results showed that the PETTLEP imagery group and physical practice group improved from pre-test to posttest, whereas the traditional imagery group and control group did not. These two studies indicate that PETTLEP imagery is more beneficial to performance than traditional imagery, and as effective as physical practice. Study 3 and 4 compared differing amounts of PETTLEP imagery on a netball task (over a four week period) and a strength task (over a twenty-two week period). Results indicated that the larger the amount of imagery completed, the larger the apparent performance effect. However, there were exceptions and this should be investigated further with differing doses of imagery, focussing on frequency and volume of imagery. This series of studies has shown PETTLEP imagery to be effective in improving performance on a variety of tasks, including cognitive, motor and strength tasks. It has also shown PETTLEP to be effective over a number of timescales, ranging from forty five minutes to twenty two weeks. In the first two studies it was shown to be as effective as physical practice. Therefore, sport psychologists and coaches should follow the guidelines set out in the PETTLEP model to individualise their imagery interventions and increase their functional equivalence. Additionally, the amount of imagery completed and its ratio to physical practice should also be considered in order to have the greatest possible effect on sports performance. Supplied by The British Library - 'The world's knowledge'
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Luzzeri, Matteo. "Motor Imagery and Performance| The Role of Movement and Perspective." Thesis, University of Louisiana at Lafayette, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1592624.
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The superior performance-enhancing features of dynamic imagery over static imagery have been defended by current motor imagery theories, especially those stressing functional equivalence. However, a substantial lack of applied research on the role of movement in motor imagery leaves this claim without the necessary support. On the other hand, the visual perspective of motor imagery has received a lot of attention, and several theories emerged addressing the conditions in which internal or external visual imagery should be employed. Among other issues, this study addressed the question of whether moving while imagining leads to increased performance enhancement. Also, differences in performance enhancement due to perspective were investigated. Eighty introductory psychology students were randomly assigned to a movement and a perspective condition, leading to four experimental groups and a fifth control group that received no imagery training. A dart-throwing task was used to investigate performance enhancements over four trials. Videos from different points of view were used as the sole perspective-inducing method, while imagery training was aided by audio scripts presented before each dart-throwing trial. Results showed a nonsignificant perspective main effect in the way in which participants improved across trials. This finding is in line with previous research using a dart-throwing task. However, contrary to prediction, this study did not find a significant movement main effect. However, the video proved to be an effective perspective-inducing method. The applied implications of these findings are discussed, as are future research directions.
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Dalhoumi, Sami. "On pattern classification in motor imagery-based brain-computer interfaces." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS240.
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Une interface cerveau-machine (ICM) est un système qui permet d'établir une communication directe entre le cerveau et un dispositif externe, en contournant les voies de sortie normales du système nerveux périphérique. Différents types d'ICMs existent dans la littérature. Parmi eux, les ICMs basées sur l'imagerie motrice sont les plus prometteuses. Elles sont basées sur l'autorégulation des rythmes sensorimoteurs par l'imagination de mouvement des membres différents (par exemple, imagination du mouvement de la main gauche et la main droite). Les ICMs basées sur l'imagerie motrice sont les meilleurs candidats pour les applications dédiées à des patients sévèrement paralysés mais elles sont difficiles à mettre en place parce que l'autorégulation des rythmes du cerveau n'est pas une tâche simple.Dans les premiers stades de la recherche en ICMs basées sur l'imagerie motrice, l'utilisateur devait effectuer des semaines, voire des mois, d'entrainement afin de générer des motifs d'activité cérébrale stables qui peuvent être décodés de manière fiable par le système. Le développement des techniques d'apprentissage automatique supervisé spécifiques à chaque utilisateur a permis de réduire considérablement la durée d'entrainement en ICMs. Cependant, ces techniques sont toujours confrontées aux problèmes de longue durée de calibrage et non-stationnarité des signaux cérébraux qui limitent l'utilisation de cette technologie dans la vie quotidienne. Bien que beaucoup de techniques d'apprentissage automatique avancées ont été essayées, ça reste toujours pas un problème non résolu.Dans cette thèse, j'étudie de manière approfondie les techniques d'apprentissage automatique supervisé qui ont été tentées afin de surmonter les problèmes de longue durée de calibrage et la non-stationnarité des signaux cérébraux en ICMs basées sur l'imagerie motrice. Ces techniques peuvent être classées en deux catégories: les techniques qui sont invariantes à la non-stationnarité et les techniques qui s'adaptent au changement. Dans la première catégorie, les techniques d'apprentissage par transfert entre différentes sessions et/ou différents individus ont attiré beaucoup d'attention au cours des dernières années. Dans la deuxième catégorie, différentes techniques d'adaptation en ligne des modèles d'apprentissage ont été tentées. Parmi elles, les techniques basées sur les potentiels d'erreurs sont les plus prometteuses. Les deux principales contributions de cette thèse sont basés sur des combinaisons linéaires des classificateurs. Ainsi, ces méthodes sont accordées un intérêt particulier tout au long de ce manuscrit. Dans la première contribution, je étudie l'utilisation de combinaisons linéaires des classificateurs dans les ICMs basées sur l'apprentissage par transfert et je propose une méthode de classification inter-sujets basée sur les combinaisons linéaires de classifieurs afin de réduire le temps de calibrage en ICMs. Je teste l'efficacité de la méthode de combinaison de classifieurs utilisée et j'étudie les cas ou l'apprentissage par transfert a un effet négatif sur les performances des ICMs. Dans la deuxième contribution, je propose une méthode de classification inter-sujets qui permet de combiner l'apprentissage par transfert l'adaptation en ligne. Dans cette méthode, l'apprentissage par transfert est effectué en combinant linéairement des classifieurs appris à partir de signaux EEG de différents sujets. L'adaptation en ligne est effectué en mettant à jours les poids de ces classifieurs d'une manière semi-superviséeA brain-computer interface (BCI) is a system that allows establishing direct communication between the brain and an external device, bypassing normal output pathways of peripheral neuromuscular system. Different types of BCIs exist in literature. Among them, BCIs based on motor imagery (MI) are the most promising ones. They rely on self-regulation of sensorimotor rhythms by imagination of movement of different limbs (e.g., left hand and right hand). MI-based BCIs are best candidates for applications dedicated to severely paralyzed patients but they are hard to set-up because self-regulation of brain rhythms is not a straightforward task.In early stages of BCI research, weeks and even months of user training was required in order to generate stable brain activity patterns that can be reliably decoded by the system. The development of user-specific supervised machine learning techniques allowed reducing considerably training periods in BCIs. However, these techniques are still faced with the problems of long calibration time and brain signals non-stationarity that limit the use of this technology in out-of-the-lab applications. Although many out-of-the-box machine learning techniques have been attempted, it is still not a solved problem.In this thesis, I thoroughly investigate supervised machine learning techniques that have been attempted in order to overcome the problems of long calibration time and brain signals non-stationarity in MI-based BCIs. These techniques can be mainly classified into two categories: techniques that are invariant to non-stationarity and techniques that adapt to the change. In the first category, techniques based on knowledge transfer between different sessions and/or subjects have attracted much attention during the last years. In the second category, different online adaptation techniques of classification models were attempted. Among them, techniques based on error-related potentials are the most promising ones. The aim of this thesis is to highlight some important points that have not been taken into consideration in previous work on supervised machine learning in BCIs and that have to be considered in future BCI systems in order to bring this technology out of the lab. The two main contributions of this thesis are based on linear combinations of classifiers. Thus, these methods are given a particular interest throughout this manuscript. In the first contribution, I study the use of linear combinations of classifiers in knowledge transfer-based BCIs and I propose a novel ensemble-based knowledge transfer framework for reducing calibration time in BCIs. I investigate the effectiveness of the classifiers combination scheme used in this framework when performing inter-subjects classification in MI-based BCIs. Then, I investigate to which extent knowledge transfer is useful in BCI applications by studying situations in which knowledge transfer has a negative impact on classification performance of target learning task. In the second contribution, I propose an online inter-subjects classification framework that allows taking advantage from both knowledge transfer and online adaptation techniques. In this framework, called “adaptive accuracy-weighted ensemble” (AAWE), inter-subjects classification is performed using a weighted average ensemble in which base classifiers are learned using EEG signals recorded from different subjects and weighted according to their accuracies in classifying brain signals of the new BCI user. Online adaptation is performed by updating base classifiers' weights in a semi-supervised way based on ensemble predictions reinforced by interaction error-related potentials
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Sharma, Nikhil. "Mapping Motor Imagery in stroke using functional Magentic Resonance Imaging." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613187.
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Jiang, Dan. "Imagery : effects on motor performance and exploration of neural substrates." Thesis, Bangor University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664524.
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This thesis is written as a collection of research papers detailing four studies through which imagery perspectives, modality, ability and their neural substrates were investigated. Study 1 explored the effects of internal visual imagery and external visual imagery on the performance of a slalom-based motor task, with the results demonstrating beneficial performnance effects for internal visual imagery over external visual imagery. Study 2 followed the design of study 1, and further examined the effects of imagery modality (visual and kinaesthetic) on the performance of the slalom-based task. The results revealed that kinaesthetic imagery provided beneficial effects over internal visual imagery. Study 3 applied the Vividness of Movement Imagery Questionnaire-2 (VMIQ-2) and fMRI to study the brain activation underpinning internal visual imagery, external visual imagery and kinaesthetic imagery. Results showed internal visual imagery, external visual imagery and kinaesthetic imagery elicited both common areas of activation (in the right supplementary motor area, BA6) and dissociated areas of activation. Specifically, internal visual imagery compared to both external visual imagery and kinaesthetic imagery activated occipital and parietal and frontal brain areas (i.e., the dorsal stream) while external visual imagery activated the occipital ventral stream areas and kinaesthetic imagery activated caudate and cerebellum areas. Study 4 investigated the neural substrates of high and low imagers for different visual imagery perspectives and modality using fMRI. More brain activations were detected in the low imagers than the high imagers during all imagery conditions. Specifically, the medial temporal lobe and the superior temporal gyrus showed more activation in the low imagers. From these results it can be suggested that individuals with lower imagery ability are less efficient in recruiting relevant brain areas to generate vivid images than those with higher imagery ability.
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Mathews, Simon. "Motor preparation with advance information in movement imagery and observation." Thesis, University of Surrey, 2008. http://epubs.surrey.ac.uk/844603/.
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An ongoing subject of research in the field of human motor control is the extent of similarities in neural activity underlying overt movement execution compared with imagination and observation of movement. Previous work in this area has focused mainly on the 'active' phase of movement (i.e. the period during which movements are actually executed, imagined or observed). Activation of motor cortical areas has been demonstrated during the active phase of motor imagery and observation suggesting that these alternative modes of movement share underlying neural mechanisms with overt motor execution. This thesis aimed to extend this work by studying the preparatory phase of movement, known to be an important part of the production of a motor response. Using high-density electroencephalography (EEG) recorded in a response-priming paradigm the effects of providing advance information about an upcoming movement were compared in the context of execution, imagination and observation of movement. For imagined movements, similar effects of advance information on preparatory activity were demonstrated to those shown prior to executed movements, providing further support for the theory that motor imagery activates existing neural representations of movement in motor areas of the brain (the neural simulation theory). For observed movements, by contrast, advance information about the upcoming movement did not invoke motor- related preparatory activity suggesting that similarities in motor execution and observation do not extend into the preparatory phase. This was interpreted as reflecting the passive nature of movement observation compared with the willful generation of a motor action in movement imagery and execution. In conclusion, an investigation into the preparatory phase of movement in this thesis suggests that motor imagery, in comparison to motor observation, provides a closer correlate to actual movement execution in terms of shared underlying neural activation.
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Holmes, Paul Stewart. "The development of a functional equivalence model for motor imagery." Thesis, Manchester Metropolitan University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326769.
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Belizario, Paul Augusto Bustios. "Seleção de bandas de frequência na classificação de eletroencefalogramas de imagética motora." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-21092017-165153/.
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Imagética motora é um processo mental que produz modulações na amplitude dos sinas de eletroencefalogramas em progresso. Os padrões presentes nestas modulações podem ser usados para classificar este processo mental, mas a identificação destes padrões não é uma tarefa trivial, porque eles estão presentes em bandas de frequências que são específicas para cada pessoa. Neste trabalho, apresenta-se um novo método para selecionar as bandas de frequência específicas para cada pessoa baseado na arquitetura do método Filter Bank Common Spatial Pattern. Para selecionar as bandas de frequência mais relevantes para cada pessoa, o método proposto aplica uma busca exaustiva para encontrar o melhor subconjunto de bandas de frequência contendo os padrões mais discriminativos dentro de um espaço de busca restrito a um tamanho fixo para este subconjunto. Esse tamanho é determinado usando validação cruzada e o método Sequential Forward Floating Selection. O método proposto foi avaliado usando a base de dados pública 2b da BCI Competition IV, mostrando melhores resultados do que todos os métodos também avaliados nessa base de dados.Motor imagery is a mental process that when performed, produces modulations in the amplitude of ongoing electroencephalogram signals. These modulations happen following a series of patterns that can be used to classify this mental process, but the detection of those patterns is not a trivial task, because they occur in frequency bands that are specific for each person. In this work, we present a method to select these subject-specific frequency bands based on the arquitecture of the Filter Bank Common Spatial Pattern approach. To select the most relevant frequency bands for each person, our method uses an exhaustive search to find the best subset of frequency bands containing the most discriminative patterns, but with one restriction, the search space is restricted to find a subset with a fixed number of frequency bands. The number is determined using cross-validation and the Sequential Forward Floating Selection method. We demonstrate that, using the data set 2b of the BCI Competition IV, our method is more accurate than current methods evaluated on the same data set.
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Herrera, Altamira Gabriela. "Vibrotactile feedback to support kinesthetic motor imagery in a brain-computer interface for post-stroke motor rehabilitation." Electronic Thesis or Diss., Université de Lorraine, 2024. https://docnum.univ-lorraine.fr/ulprive/DDOC_T_2024_0002_HERRERA_ALTAMIRA.pdf.
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Les interfaces cerveau-ordinateur (ICOs) basées sur l'imagination motrice offrent des solutions prometteuses pour la rééducation motrice des patients après un accident vasculaire cérébrale (AVC). L'imagerie motrice kinesthésique (IMK) consiste à imaginer les sensations d'un mouvement, telles que la température, la pression, la rugosité, la contraction musculaire et l'activation nerveuse, plutôt que de visualiser le mouvement. Cependant, l'IMK ne comporte pas de retour sensoriel ou kinesthésique, ce qui rend cette tâche difficile à comprendre, à apprendre et à réaliser. Cette absence de retour d'information, ou feedback en anglais, restreint l'évaluation de la performance et l'orientation thérapeutique des patients post-AVC. Pour faire face à ce problème, un retour d'information est fourni aux patients et aux thérapeutes en fonction de la performance du patient. Diverses modalités de feedback ont été étudiées pour résoudre ce problème, notamment visuelles, la stimulation électrique fonctionnelle, les exosquelettes et les robots. Le feedback vibrotactile est une alternative peu explorée, qui vise à stimuler la peau et s'adresse aux patients avec une mobilité très réduite qui ne peuvent pas profiter des autres solutions. La combinaison des différents feedbacks est révélée comme une approche prometteuse pour fournir un retour d'information plus efficace et améliorer le processus de réadaptation. Le développement du feedback pour les ICOs a souvent donné la priorité au progrès technologique plutôt qu'aux considérations centrées sur le patient, ce qui a eu pour conséquence une adoption clinique limitée. Cette thèse adopte une nouvelle approche de recherche basée sur la conception (desing-based research en anglais, DBR), plaçant l'utilisateur au cœur du développement du système du retour d'information. L'objectif est de concevoir et d'évaluer un feedback vibrotactile, complémenté par un feedback visuel, et de l'intégrer à une ICO basée sur l'IMK pour améliorer la rééducation motrice post-AVC. Nous commençons par identifier les besoins et les objectifs des patients post-AVC qui suivent un entraînement par une ICO. Comme résultat, nous avons formulé l'hypothèse que le feedback bimodal (intégrant les modalités vibrotactiles et visuelles) peut améliorer l'IMK dans le contexte d'interaction avec une ICO. Le dispositif vibrotactile est ensuite construit en tenant compte des limitations anatomiques et physiques des patients post-AVC. Ensuite, la stimulation vibrotactile est construite en deux phases : établissement des seuils sensoriels de vibration pour trois groupes des âges différents et synchronisation d'un environnement visuel avec la stimulation vibrotactile. Différents modèles de vibration sont comparés pour déterminer celui qui correspond le mieux à l'animation graphique. La stimulation a été conçue en s'inspirant de l'activation des muscles lors d'un mouvement de préhension. Après la validation de la stimulation, l'ICO est évaluée auprès d'un groupe de participants neurotypiques afin de mesurer l'efficacité, l'utilisabilité et la fiabilité du système. Trois modalités de feedback (vibrotactile, visuelle, bimodal — vibrotactile et visuelle) sont comparées pour évaluer leur efficacité à soutenir l'exécution de l'IMK. Cette recherche met en évidence le potentiel d'une approche centrée sur l'utilisateur pour développer des solutions de feedback qui améliorent l'IMK et la rééducation. Un protocole expérimental est présenté pour une future étude chez les patients post-AVC afin d'évaluer l'acceptabilité et l'utilisabilité de l'ICO avec un feedback bimodal méticuleusement conçu. Les résultats de ce travail offrent les basses pour l'application de notre ICO dans la pratique clinique, avec le potentiel de bénéficier les patients post-AVCMotor imagery-based brain-computer interfaces (BCI) offer promising solutions for post-stroke motor rehabilitation. Kinesthetic motor imagery (KMI) consists of imagining the sensations of a movement (such as temperature, pressure, roughness, muscular contraction, and nerve activation) rather than visualizing the movement. However, KMI lacks sensory or kinesthetic feedback, making this task challenging to understand, learn, and perform. This absence of feedback hinders performance evaluation and therapeutic guidance for post-stroke patients. To address this issue, feedback is provided to both patients and therapists, based on the patient's performance. Various feedback modalities, including visual, functional electrical stimulation, exoskeletons, and robotic assistance, have been explored to bridge this gap. Vibrotactile feedback is an underexplored alternative, that offers skin stimulation, targeting patients with limited mobility. Combining different feedback modalities has emerged as a promising approach to provide more effective feedback and enhance the rehabilitation process. The development of BCI feedback has often prioritized technological advancement over patient-centric considerations, resulting in limited clinical adoption. This thesis adopts a novel design-based research (DBR) approach, placing the user at the core of feedback system development. The objective is to design and evaluate vibrotactile feedback, complemented with visual feedback and integrated it with a KMI-based BCI to improve post-stroke motor rehabilitation. We start by identifying the needs and objectives of patients undergoing BCI training, leading to the hypothesis that bimodal feedback (combining vibrotactile and visual modalities) can enhance KMI within the BCI context. We tailor the vibrotactile stimulation to provide precise sensory feedback during grasping KMI. The vibrotactile device is then built considering the anatomical and physical limitations of post-stroke patients. Then, the vibrotactile stimulation is built in two phases: establishing vibration sensory thresholds for age-dependent groups and synchronizing a visual environment with vibrotactile stimulation. Different vibration patterns are compared to determine the one that better corresponds to the graphic animation. The stimulation was designed, drawing inspiration from the natural muscle activation of the muscles during grasping. Following the validation of the stimulation, the BCI is assessed with a group of neurotypical participants to measure its efficacy in improving KMI and evaluate its acceptability, usability, and reliability. Three feedback modalities (vibrotactile, visual and bimodal - vibrotactile and visual) are compared to determine their effectiveness. This research highlights the potential of a user-centered approach for developing feedback solutions that enhance motor imagery and rehabilitation outcomes. Furthermore, an experimental protocol is presented for future studies with post-stroke patients to assess the acceptability and usability of the meticulously designed BCI with bimodal feedback. The findings of this work lay the foundation for translating the resulting BCI into practical clinical applications, ultimately benefiting post-stroke patients
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Lingvall, Johanna. "The Impact of Motor Imagery on Sport Performance and the Brain's Plasticity." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-17257.
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New neuroimaging techniques have made it possible to examine imagery and found evidence for that imagery share similar neural correlates as in perception. Imagery can be used in different areas to enhance performance, and it is a popular technique in sports. Similar to physical practice (PP), motor imagery (MI) can result in brain plasticity. The aim of this thesis is to describe what imagery means and describe different theories of imagery. This is to further look into what impact MI has on performance in different sports, and then to further see if there are any changes in brain plasticity as a result of using MI. There is a lack of studies done on MI, performance and brain plasticity in sport. To answer the latter focus of this thesis, studies of healthy persons and patient studies using MI to improve performance and examining changes in the brain have been used. In order to do that this thesis aims to do a literature review. The results indicate that MI combined with PP can improve sport performance. It has also been showed that MI alone can be as good as PP. Most studies found that MI combined with PP can result in brain plasticity, and only one study did not found evidence for it. It has also showed that MI alone can result in brain plasticity. Future research should include larger samples, matching subjects, and comparing the effects of MI in several kinds of sports.
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Gherdovich, Tommaso. "Efficacia della motor imagery nella riabilitazione delle persone colpite da ictus." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16887/.
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Background: l’ictus è una patologia che può provocare disabilità di grado importante con limitazioni delle attività e della partecipazione alla vita sociale delle persone colpite, impegno gravoso per i caregivers e ingente spesa sanitaria. Da circa vent’anni si sta indagando la motor imagery o immaginazione del gesto motorio, strategia riabilitativa utilizzata già negli atleti sportivi per favorire l’apprendimento di nuove abilità motorie. Questo processo va ad attivare aree cerebrali in parte sovrapponibili a quelle reclutate durante il gesto motorio. La pratica mentale, applicata alla riabilitazione neurologica, potrebbe favorire il riapprendimento di abilità perse.
L’obbiettivo di questo lavoro è quello di andare a verificare le evidenze a favore di questo tipo di intervento.
Materiali e metodi: ricercando articoli su tre banche dati, PubMed, PEDro e Chochrane CDSR, si è provato a valutare l’efficacia della motor imagery nella riabilitazione post-stroke. Le revisioni sistematiche prese in considerazione si sono concentrate sull’efficacia della motor imagery nei protocolli riabilitativi dopo stroke, includendo anche studi riguardanti le aree attivate durante l’immaginazione mentale di un’azione e le problematiche che determinate lesioni ad aree cerebrali possono portare alla corretta formazione dell’immagine motoria.
Risultati: sono state valutate principalmente cinque revisioni sistematiche, senza restrizioni di outcomes, nel tentativo di arrivare a una conclusione sull’efficacia della motor imagery in seguito a ictus.
Discussione e conclusioni: è impossibile giungere a conclusioni definitive a causa della grande eterogeneità presente tra i vari studi che rende impossibile generalizzare i risultati ottenuti.
Per quanto possa sembrare un valido strumento riabilitativo, la motor imagery necessita ancora di approfondimenti e trials più rigorosi dal punto di vista metodologico, per poter arrivare a una valida conclusione sulla sua efficacia.
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MELO, GABRIEL CHAVES DE. "ALGORITHMS FOR MOTOR IMAGERY PATTERN RECOGNITION IN A BRAIN-MACHINE INTERFACE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34769@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Uma interface cérebro-máquina (ICM) é um sistema que permite a um indivíduo, entre outras coisas, controlar um dispositivo robótico por meio de sinais oriundos da atividade cerebral. Entre os diversos métodos para registrar os sinais cerebrais, destaca-se a eletroencefalografia (EEG), principalmente por ter uma rápida resposta temporal e não oferecer riscos ao usuário, além de o equipamento ter um baixo custo relativo e ser portátil. Muitas situações podem fazer com que uma pessoa perca o controle motor sobre o corpo, mesmo preservando todas as funções do cérebro, como doenças degenerativas, lesões medulares, entre outras. Para essas pessoas, uma ICM pode representar a única possibilidade de interação consciente com o mundo externo. Todavia, muitas são as limitações que impossibilitam o uso das ICMs da forma desejada, entre as quais estão as dificuldades de se desenvolver algoritmos capazes de fornecer uma alta confiabilidade em relação ao reconhecimento de padrões dos sinais registrados com EEG. A escolha pelas melhores posições dos eletrodos e as melhores características a serem extraídas do sinal é bastante complexa, pois é altamente condicionada à variabilidade interpessoal dos sinais. Neste trabalho um método é proposto para escolher os melhores eletrodos e as melhores características para pessoas distintas e é testado com um banco de dados contendo registros de sete pessoas. Posteriormente dados são extraídos com um equipamento próprio e uma versão adaptada do método é aplicada visando uma atividade em tempo real. Os resultados mostraram que o método é eficaz para a maior parte das pessoas e a atividade em tempo real forneceu resultados promissores. Foi possível analisar diversos aspectos do algoritmo e da variabilidade inter e intrapessoal dos sinais e foi visto que é possível, mesmo com um equipamento limitado, obter bons resultados mediante análises recorrentes para uma mesma pessoa.
A brain-machine interface (BMI) system allows a person to control robotic devices with brain signals. Among many existing methods for signal acquisition, electroencephalography is the most often used for BCI purposes. Its high temporal resolution, safety to use, portability and low cost are the main reasons for being the most used method. Many situations can affect a person s capability of controlling their body, although brain functions remain healthy. For those people in the extreme case, where there is no motor control, a BCI can be the only way to interact with the external world. Nevertheless, it is still necessary to overcome many obstacles for making the use of BCI systems to become practical, and the most important one is the difficulty to design reliable algorithms for pattern recognition using EEG signals. Inter-subject variability related to the EEG channels and features of the signal are the biggest challenges in the way of making BCI systems a useful technology for restoring function to disabled people. In this paper a method for selecting subject-specific channels and features is proposed and validated with data from seven subjects. Later in the work data is acquired with different EEG equipment and an adapted version of the proposed method is applied aiming online activities. Results showed that the method was efficient for most people and online activities had promising results. It was possible to analyze important aspects concerning the algorithm and inter and intrasubject variability of EEG signals. Also, results showed that it is possible to achieve good results when multiple analyses are performed with the same subject, even with EEG equipment with well known limitations concerning signal quality.
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Wahl, Casper. "Training Autoencoders for feature extraction of EEG signals for motor imagery." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-53392.
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Electroencephalography (EEG) is a common technique used to read brain activity from an individual, and can be used for a wide range of applications, one example is during the rehab process of stroke victims. Loss of motor function is a common side effect of strokes, and the EEG signals can show if sufficient activation of the part of the brain related to the motor function that the patient is training has been achieved. Reading and understanding such data manually requires extensive training. This thesis proposes to use machine learning to automate the process of determining if sufficient activation has been achieved. The process consists of a Long Short Term Memory (LSTM) Autoencoder that trains to extract features of the EEG data to be used for classification using various machine learning classification methods. In order to answer the research questions: “How to extract features from EEG signals using Autoencoders?” “Which supervised machine learning algorithm identifies as the best classification based on the features generated by the Autoencoder?” The results show that the accuracy varies greatly from individual to individual, and that the number of features created by the Autoencoder for the classification algorithms to work with has a large impact on accuracy. The choice of classification algorithm played a role for the result as well, with Support Vector Machine (SVM) performing the best, but had less impact than the previously mentioned factors.
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Cattai, Tiziana. "Leveraging brain connectivity networks to detect mental states during motor imagery." Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS081.
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Le cerveau est un réseau complexe et nous savons que les mécanismes de synchronisation et de désynchronisation sont essentiels pour effectuer des taches motrices et cognitives. De nos jours, les interactions fonctionnelles cérébrales sont étudiées dans des applications d'interface cerveau-ordinateur (BCI) avec de plus en plus d'intérêt. Cela pourrait avoir un fort impact sur les systèmes BCI, généralement bases sur des caractéristiques univariées qui caractérisent séparément les activités régionales du cerveau. En effet, les fonctionnalités de connectivité cérébrale peuvent être utilisées pour développer des BCI alternatifs dans le but d'améliorer les performances et d'\'e9tendre leur applicabilité dans la vie r\'e9elle. L'ambition de cette thèse est l'étude des réseaux de connectivité fonctionnelle du cerveau lors de taches BCI basées sur l'imagerie motrice (IM). Il vise à identifier le fonctionnement cérébral complexe, les processus de réorganisation et les dynamiques variant dans le temps à la fois au niveau du groupe et de l'individu. Cette thèse présente différents développements qui enrichissent séquentiellement un modèle initialement simple afin d'obtenir une méthode robuste pour l'étude des réseaux de connectivité fonctionnelle. Les résultats expérimentaux sur des données EEG simulées et réelles enregistrés pendant les taches BCI prouvent que notre méthode proposée explique bien le comportement variegate des données EEG cérébrales. Plus précisément, il fournit une caractérisation des mécanismes fonctionnels du cerveau au niveau du groupe, ainsi qu'une mesure de la séparabilité des conditions mentales au niveau individuel. Nous présentons également une procédure de réduction du bruit de graphe pour filtrer les données qui préservent simultanément la structure de connectivité du graphe et améliorent le rapport signal sur bruit. Puisque l'utilisation d'un système BCI nécessite une interaction dynamique entre l'utilisateur et la machine, nous proposons enfin une méthode pour capturer l'évolution des données variant dans le temps. Essentiellement, cette thèse présente un nouveau cadre pour saisir la complexité de la connectivité fonctionnelle des graphes lors de tâches cognitivesThe brain is a complex network and we know that inter-areal synchronization and de-synchronization mechanisms are crucial to perform motor and cognitive tasks. Nowadays, brain functional interactions are studied in brain-computer interface BCI) applications with more and more interest. This might have strong impact on BCI systems, typically based on univariate features which separately characterize brain regional activities. Indeed, brain connectivity features can be used to develop alternative BCIs in an effort to improve performance and to extend their real-life applicability. The ambition of this thesis is the investigation of brain functional connectivity networks during motor imagery (MI)-based BCI tasks. It aims to identify complex brain functioning, re-organization processes and time-varying dynamics, at both group and individual level. This thesis presents different developments that sequentially enrich an initially simple model in order to obtain a robust method for the study of functional connectivity networks. Experimental results on simulated and real EEG data recorded during BCI tasks prove that our proposed method well explains the variegate behaviour of brain EEG data. Specifically, it provides a characterization of brain functional mechanisms at group level, together with a measure of the separability of mental conditions at individual level. We also present a graph denoising procedure to filter data which simultaneously preserve the graph connectivity structure and enhance the signal-to-noise ratio. Since the use of a BCI system requires a dynamic interaction between user and machine, we finally propose a method to capture the evolution of time-varying data. In essence, this thesis presents a novel framework to grasp the complexity of graph functional connectivity during cognitive tasks
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Khalaf, Bassem. "The contribution of planning-related motor processes to mental practice and imitation learning." Thesis, University of Plymouth, 2014. http://hdl.handle.net/10026.1/2972.
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It is still controversial whether mental practice – the internal rehearsal of movements to improve later performance – relies on processes engaged during physical motor performance and, if so, which processes these are. This series of experiments investigates this question. It utilizes a framework of ideomotor action planning theories, and tests whether mental practice may specifically draw upon planning- rather than execution-related motor processes, specifically those processes that “bind” intended action features to action plans. Experiments 1 to 4 utilize a classical stimulus response compatibility paradigm. Participants mentally practiced complex rhythms with either feet or hands while using the same or different body parts to respond to unrelated sounds. In contrast to previous work on stimulus response compatibility, we indeed found that responses were impaired – rather than facilitated – for those body parts that were concurrently used in mental practice. This result was found when participants mentally trained to memorize the rhythms (Experiment 1), to merely improve their performance (Experiment 3), when mental practice and execution directly followed one another and when separated by a different task (Experiment 4). These data link mental practice not to execution but planning related motor processes that are involved in binding intended action features to intended action plans. Experiment 5 and 6 then extend these results to imitation learning. Participants were instructed to learn the rhythms by observing somebody else, while again making unrelated responses with their hand and feet. While previous work on stimulus response compatibility focussed on testing automatic imitation processes, here imitation was therefore goal directed. We found, as in the previous experiments, that responses with the same body parts as used in the observed rhythms were impaired, suggesting that goal-directed imitation might rely on the same planning-related motor processes as the mental practice of action (Experiment 5). Importantly, these effects were only found as long as participants observed the actions with VI the purpose of imitating them later (i.e. formed action plans), but not when they merely tried to memorize the rhythms for later recognition (Experiment 6). The previous experiments suggest that mental practice and observation learning draw upon body-part specific planning processes. Ideomotor theories suggest, however, that action plans can be relatively abstract, and represented in terms of higher-level goals (i.e. the sequence of left and right button presses independent of the body part used). Experiment 7 and 8 therefore tested whether rhythms learned through mental practice or observation learning could be transferred to other body parts. As expected, we found a relatively high amount of potential transfer when rhythms were mentally practiced with one body part, and then had to be transferred to another body part (Experiment 7). However, this only held when participants learned the rhythms based on an abstract rhythm description, as in Experiments 1 to 4. If participants learned the same rhythms during action observation, any benefits were only obtained when the rhythms later had to be executed with the same (rather than a different) body part. Together, the present data suggest that mental practice does not rely on execution related-motor processes, and points to an involvement of planning related motor processes instead. We argue that such a planning-based account of mental practice is more compatible with the available evidence from body neuroscientific and behavioral studies, and allows one to resolve several debates. Moreover, it allows one to conceptualize goal-directed imitation in a similar manner as mental practice.
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Delbecque, Laure. "Incidence de l'imagerie motrice sur les apprentissages moteurs." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210527.
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The topic of this work is motor imagery. Through 7 different studies, the process and proprieties of motor imagery and its impact on motor learning were assessed. It was found that this cognitive activity is closely linked to the motor system. This characteristic underlies the positive effects of motor imagery on motor learning. This can have many practical applications in the domain of sport and motor rehabilitation.
Doctorat en Sciences Psychologiques et de l'éducation
info:eu-repo/semantics/nonPublished
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Morel, Fanny. "O efeito da imagética motora no tratamento da dor fantasma em amputados: revisão bibliográfica." Bachelor's thesis, [s.n.], 2018. http://hdl.handle.net/10284/6732.
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Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciada em FisioterapiaIntrodução: a imagética tem sido utlizada como forma de diminuir a dor fantasma de um indivíduo amputado de um membro superior ou inferior. Objetivo: verificar os efeitos da utilização da imagética motora nos indivíduos amputados com dor fantasma. Metodologia: pesquisa com palavras-chave na base de dados Pubmed, PEDro e b-on para identificar estudos publicados nos últimos 15 anos, randomizados controlados, randomizados não controlados, estudos de casos, publicados em inglês, que utilizassem a imagética no tratamento da dor fantasma em indivíduos com uma amputação unilateral de um membro. Foram excluídos estudos fora do assunto escolhido, e as revistas sistemáticas e os protocolos. Resultados: foram identificados 2 artigos randomizados controlados e 3 estudos de caso. Conclusão: a imagética parece ser uma boa técnica para a dor fantasma em amputados, no entanto é necessário mais estudos randomizados controlados e com amostra maior para poder afirmar que a imagética mental tem realmente efeitos benéficos no alivío da dor fantasma.
Introduction: The imagery has been used as a way to reduce the phantom pain of an individual amputated from an upper or lower limb. Objective: To verify the positive effects of the use of imagery in amputated individuals with phantom pain. Methodology: Keyword research in the Pubmed, PEDro and b-on database to identify studies published in the last 15 years, randomized controlled, and uncontrolled trials, case studies, published in English and which deal with the use of imotor imagery in the treatment of phantom limb pain in individuals with unilateral limb amputation. We excluded studies outside the chosen subject, with the systematic reviews and protocols. Results: 2 randomized controled articles were indentified and 3 case studies. Conclusion: imagery seems to be a good technique for phantom pain in amputees, however more randomized controlled trials with a larger sample are needed to be able to affirm that mental imagery actually has beneficial effects in the alleviation of phantom pain.
N/A
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Wohldmann, Erica L. "Pushing the limits of imagination: The effectiveness of motor imagery for acquiring and maintaining a sequential motor skill." Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3207743.
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Hale, Brendon S. "The effects of motor imagery on the Hoffmann Reflex and presynaptic inhibition." [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3274271.
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Thesis (Ph.D.)--Indiana University, Dept. of Kinesiology, 2007.Source: Dissertation Abstracts International, Volume: 68-07, Section: B, page: 4882. Adviser: John S. Raglin. Title from dissertation home page (viewed Apr. 21, 2008).
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Abdulgabbar, Adel S. "The effect of imagery ability on imitation of a closed-motor task." Thesis, University of Warwick, 1990. http://wrap.warwick.ac.uk/106718/.
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This thesis sets out to explore the process of motor skill acquisition and presents a thorough investigation of the role played by imagery ability in the recall and reproduction of a motor task. The importance of cognitive processes, such as imaging, in motor learning is becoming increasingly obvious and needs to be understood. Having described the three phases involved in motor learning - cognitive, associative and autonomous - and discussed certain relevant learning theories- the closed-loop theory and the schema theory- the thesis moves on to examine traditional Instructional methods and the contrast between observational learning and verbal instruction techniques, analysing in detail the concept of mental imagery in context of the recall of motor task. The latter half of the thesis presents a series of experiments designed to quantify the role of Imagery ability in reproduction of an origami (paper-folding) task using the different instructional methods and a variety of modelled demonstrations and comparing accuracy and performance time. The thesis concludes that observers who transform modelled actions into either symbolic or visual images achieve a higher level of learning and a higher standard of reproduction than non-imagers, and looks forward to an expansion of research into imaging in a variety of contexts. The results of this study have implications for those working in selecting new trainees for most industrial firms, and their concern with the assessment of selecting individuals on their learning ability and the factors contributing to this as well as the possible instructional methods to be carefully considered with respect to the cost/benefit of such an exercise.
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Mamone, Bernadett. "MOTOR IMAGERY TRAINING FACILITATES NEURAL ADAPTATIONS ASSOCIATED WITH MUSCLE STRENGTHENING IN AGING." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1374150888.
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Tidare, Jonatan. "Temporal representation of Motor Imagery : towards improved Brain-Computer Interface-based strokerehabilitation." Licentiate thesis, Mälardalens högskola, Inbyggda system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-53082.
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Practicing Motor Imagery (MI) with a Brain-Computer Interface (BCI) has shown promise in promoting motor recovery in stroke patients. A BCI records a person’s brain activity and provides feedback to the person in real time, which allows the person to practice his or her brain activity. By imagining a movement (performing MI) such as gripping with their hand, cortical areas in the brain are activated that largely overlaps with those activated during the actual hand movement. A BCI can provide positive feedback when the hand-related cortical areas are activated during MI, which helps a person to learn how to perform MI. Despite evidence that stroke patients may recover some motor function from practicing MI with BCI feedback thanks to the feedback provided from a BCI, the effectiveness and reliability of BCI-based rehabilitation are still poor. A BCI can detect MI by analyzing patterns of features from the brain activity. The most common features are extracted from the oscillatory activity in the brain. In BCI research, MI is often treated as a static pattern of features, which is detected by using machine learning algorithms to assign activity into a binary state. However, this model of MI may be inaccurate. Analyzing brain activity as dynamically varying over time and with a continuous measure of strength could better represent the cortical activity related to MI. In this Licentiate thesis, I explore a method for analyzing the temporal dynamic of MI-activity with a continuous measure of strength. Brain activity was recorded with electroencephalography (EEG) and subject-specific feature patterns were extracted from a group of healthy subjects while they performed MI of two opposing hand movements: opening and closing the hand. Although MI of the two same-hand movements could not be discriminated, the continuous output from a machine learning algorithm was shown to correlate well with MI-related feature patterns. The temporal analysis also revealed that MI is dynamically encoded early, but later stabilizes into a more static pattern of brain activity. Last, to accommodate for higher temporal resolution of MI, I designed and evaluated a BCI framework by its feedback delay and uncertainty as a function of the stress on the system and found a non-linear correlation. These results could be essential for developing a BCI with time-critical feedback. To summarize, in this Licentiate thesis I propose a promising method for analyzing and extracting a temporal representation of MI, enabling relevant and continuous neurofeedback which may contribute to clinical advances in BCI-based stroke rehabilitation.
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ZAPPAROLI, LAURA. "Mental motor representations across the adult life-span: behavioural and fMRI evidence in explicit and implicit motor imagery tasks." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2016. http://hdl.handle.net/10281/100074.
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Motor imagery (MI) is a cognitive state in which movements are mentally evoked. There is behavioural evidence that MI declines with aging, but limited information on the functional anatomical correlates of these changes.
In my thesis, I present a systematic behavioural/fMRI investigation of this issue and demonstrate that aging is associated with modified brain responses ranging from successful compensation to failed compensation depending on the complexity of the motor imagery task.
After a theoretical introduction in Chapter 1, I describe the effects of early aging on explicit MI, through a study of 24 young and 24 elderly subjects during two fMRI tasks requiring movement execution (ME) or MI of finger movements; temporal correlations between MI and ME were also measured (Chapter 2).
I found significant differences between the two groups: elderly subjects lost the behavioural temporal correlation between MI and ME; moreover, they over-recruited occipito-temporal areas. The temporal discrepancy between MI and ME in the elderly subjects correlated with brain regions that showed increased activations. These observations suggest that elderly subjects have qualitatively different explicit MI abilities.
MI can be elicited also by using implicit tasks, in which subjects are involved in motorically driven decisions. The hand laterality task is one such example: subjects are asked to decide whether a depicted hand is a left or a right one.
Chapter 3 illustrates the fMRI correlates of this task in 30 young subjects. I found stronger signals in left premotor and parietal cortices for palm-viewed stimuli, whereas back-view stimuli were associated with stronger occipital activations to suggest the existence of brain-encoded, view-dependent representations of body segments.
Chapter 4 reports the extension of the 2nd study to the assessment of the effects of early aging on implicit motor processes: I compared those data with the ones of 29 elderly subjects. While there was no specific aging related behavioural effect, I found significant additional activations in the elderly group in occipito-temporal regions, which were negatively correlated with RTs. These results reveal a pattern of graceful aging in the domain of implicit motor representations whereby cognitive performance remains at juvenile level thanks to some compensatory brain processes.
It remained to be seen whether the effect of early aging could be detected by using more complex implicit MI tasks, something addressed in Chapter 5, through the study of 22 young and 23 elderly subjects performing a Grip Selection Task in which they were asked to report whether they would grip a portrayed tool with an over- or an under-hand grip. I found a behavioural decline in the elderly group, with hyperactivations in the occipital cortices and hypoactivations in the superior parietal lobule, an area previously associated with object grasping. The greater complexity of the imagined movement may determine a pattern interpretable in terms of a failed attempt of compensation.
I conclude with Chapter 6, discussing my data in the light of neurocognitive models of healthy aging.
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Lipke-Perry, Tracy Donna. "Integrating Piano Technique, Physiology, and Motor Learning: Strategies for Performing the Chopin Etudes." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/193854.
Full textAbstract:
Chopin's twenty-seven études are both unique and standard within the genre of advanced piano literature. Having been composed as the instrument itself was standardized and on the heels of the didactic studies of the classical period, Chopin's études are widely heralded as exemplary pedagogical material for their uniform quality and comprehensiveness. Nevertheless, despite the vast number of resources devoted to the topic of how one might approach the études and the innumerable endorsements which tout their incomparable worth, relatively cursory mention is made of their musical value. From a physiological perspective, what makes Chopin's études exceptional amongst vast pedagogical repertory, and how does their musical value impact what pianists learn from their study?From a modern perspective, a musical image is both the model and the yardstick for the measure of technical achievement as one compares performance with his or her musical image. The Chopin études are therefore unique in two ways. First, a pianist's musical image of each of the Chopin études initiates an individual process of motor learning. The musical images, and therefore the goals and the processes, are inherently different from the vast majority of purely didactic studies and exercises. Secondly, the genius of Chopin permeates the overall conception of the études as he intuitively employed the human ability to develop motor skills in natural ways which continue to be understood and supported by ongoing research.This paper explores the Chopin études from a largely physiological and psychological perspective such that modern studies of mental imagery, skill acquisition, and human motor abilities converge and highlight what is readily available in the music itself.
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DE, SANTIS CARLO. "MENTAL STEPS: MOTOR IMAGERY OF GAIT IN ELDERLY AND ITS ROLE IN REHABILITATION." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2017. http://hdl.handle.net/10281/158167.
Full textAbstract:
La deambulazione è un comportamento altamente automatizzato e iperappreso, ma basato su programmi sensori motori complessi che coinvolgono numerosi centri nel tronco encefalico, nel cervelletto e nella corteccia. Il decadimento delle abilità di deambulazione è uno dei tratti che definiscono l’invecchiamento. L’osteoartrite per gli arti inferiori è considerato la maggior causa di disabilità e handicap nelle società occidentali industrializzati: è la causa maggiore di dolore muscolo scheletrico e a causa della grave limitazione funzionale molte attività della vita quotidiana sono compromesse. La comprensione della fisiologia del cammino a livello centrale, i cambiamenti dovuti all’invecchiamento o l’impatto di patologie periferiche su questa fisiologia è molto limitato.
In questa tesi ho descritto una serie di esperimenti con lo scopo di comprendere meglio la fenomenologia del cammino negli anziani e definire quanto questa abilità e la sua rappresentazione mentale, evocata tramite specifici compiti, potesse essere influenzata dall’osteoartrite al ginocchio.
Questa patologia è stata selezionata come modello di un deterioramento delle rappresentazioni del cammino a livello cortico/sottocorticale in assenza di chiari disturbi neurologici.
Lo scopo a lungo termine di questa ricerca è dare un solido razionale per poter testare l’efficacia di una riabilitazione basata su strategie di immaginazione motoria nel recupero post chirurgico.
Tramite gli esperimenti ho definito la neurofisiologia del cammino a livello centrale (sopraspinale) nell’immaginazione motoria e nell’immaginazione dell’imitazione, tramite l’uso della fMRI. Questo è stato fatto prima nei sani. Nel mio esperimento finale il pattern fMRI ottenuti per i soggetti sani sono stati confrontati con quelli di un gruppo di pazienti con osteoartrite del ginocchio.
I punti principali possono essere così riassunti: (1) i pazienti con osteoartrite al ginocchio sono ancora capaci di eseguire compiti di immaginazione motoria che coinvolgono la deambulazione; (2) ciononostante sembra che i pazienti non siano stati in grado di incorporare la loro limitazione motoria periferica nella simulazione mentale della deambulazione in quanto risultano più veloci dei loro controlli sani; (3) i dati fMRI per i soggetti sani mostrano che l’immaginazione motoria per il cammino dipende da un grande pattern fronto-parietale a livello corticale e maggiori attivazioni a livello cerebellare e del tronco encefalico, in aree legate al cammino, rispetto all’immaginazione dell’imitazione.(4) Infine i dati fMRI per i pazienti con osteoartrite hanno mostrato maggiori attivazioni per aree coinvolte nell’immaginazione motoria quando il compito di immaginazione era combinato con un’esplicita simulazione della deambulazione ossia la dorsi-flessione delle caviglie.
Insieme questi risultati (1) contribuiscono alla definizione dei pattern neurali coinvolti nell’immaginazione del cammino per cervelli sani, (2) dimostrano abilità qualitativamente differenti, ma ancora accessibili, nella rappresentazione della deambulazione per compiti di immaginazione motoria sia a livello comportamentale (3) che a livello anatomo-funzionale. Il razionale di questo studio lascia ipotizzare che l’uso dell’immaginazione motoria possa facilitare il recupero della deambulazione in pazienti con osteoartrite al ginocchio nel periodo post operatorio, magari aggiungendo qualche particolare aggiuntivo, come minimo comportamento motorio (come la dorsi-flessione della caviglia). Questo mi sarà possibile discuterlo nel momento in cui avrò terminato gli specifici esperimenti per l’uso dell’immaginazione motoria in riabilitazione.Gait is a highly automatic behavior. Although walking is an over-experienced action, stance and locomotion are based on complex sensorimotor programs that involve several distinct and separate supraspinal centers in the brainstem, cerebellum and the cortex (l’italiano sarebbe: Gait is a highly automatic and over-experienced behavior, based on complex sensorimotor programs that involve several centers in the brainstem, cerebellum and the cortex). The decay of gait related skills is one of the defining traits of ageing. Osteoarthritis in the lower limbs is considered the single most important cause of disability and handicap in Western industrialized countries: it is the main cause of musculoskeletal pain, and daily life activities are reduced due to severe functional limitation. The comprehension of the central physiology of walking and its age-related changes or the impact of peripheral disease on this physiology is very limited. In the present thesis I describe a series of experiments whose aim was to better understand the phenomenology of walking in elderly people and to assess to what extent this skill and its mental representation, evoked through specific motor imagery tasks, can be affected by a peripheral disorder such as knee osteoarthritis. This disease was chosen as a model of possible deterioration of cortical/subcortical representations of walking behavior in the absence of obvious neurological disorders. The long-term goal of this research is also to test the beneficial effect of motor-imagery-based rehabilitation strategies in guiding post-surgery recovery of the patients. The present study aims at providing a strong rationale for this overarching goal. In the same series of experiments, I characterize the central (supraspinal) neurophysiology of walking using fMRI in motor imagery or imitation through imagery. This is done in normal subjects first. In my final experiment I compare the fMRI patterns of normal subjects with those of patients with knee osteoarthritis. The main points of my experiments can be summarized as follows: (1) patients with knee osteoarthritis are still capable of motor imagery for the walking behavior; (2) yet, they seem not to have incorporated their peripheral motor limitation in the walking simulation performed during imagery as they are comparatively faster in motor imagery than the normal controls, once the time taken to walk is subtracted; (3) the fMRI data on normal controls showed that motor imagery of walking in normal controls depends on a rich fronto-parietal pattern at the cortical level with stronger activation of cerebellar and brainstem gait specific regions for motor imagery rather than imitation through imagery task. (4) Finally patients with knee osteoarthritis displayed stronger fMRI activations in walking-specific brain regions for motor imagery, compared with normal controls, providing that the motor imagery task was performed in combination with an explicit simulation of gait through explicit ankle dorsiflexion. Taken together, these results (1) contribute to the definition of the normal brain patterns associated with simulated gait, (2) testify to a qualitatively different, yet still available, ability in representing a walking behavior through motor imagery in patients with knee osteoarthritis both at a behavioral and (3) at a functional anatomical level. With some additional care, like the combination of the execution of a minimal peripheral motor behavior (the ankle dorsiflexion), the present data provide a rationale to test the hypothesis that motor imagery may prove of some use in boosting motor recovery of walking in patients with knee osteoarthritis after surgery. This is something that I should be able to discuss in person when specific experiments on motor imagery in motor rehabilitation will be completed.
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Yamada, Masahiro. "The effect of directing attention externally toward a visible or imagined object." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/theses/1982.
Full textAbstract:
Utilization of an external focus of attention has been proved to be beneficial in the motor learning literature. When people focus on the effects of the movement (i.e., external focus of attention), the motor skill is enhanced compared to directing attention to the body movements (i.e., internal focus of attention). Previous studies that have examined the effect of focus of attention on learning a motor skill often used visible or imagined objects to elicit an external focus of attention. However, the effects of these different types of external focus instruction have not been investigated thoroughly. It was unclear prior to this thesis how the focus of attention effect is influenced by the use of imagery. The purpose of the present study was to investigate the difference between directing attention to a visible object and an imagined object when performing and learning the standing long jump. It was hypothesized the group of participants who practiced with an imagery instruction would perform similarly in the post-test with or without an object that was used to elicit an external focus of attention. It was also hypothesized the group of participants who practiced with a visible object would perform similarly during the post-test with the same visible object; but the performance would decline in the post-test with no object. The results indicated there was no difference in the effect of the two different types of instructions. That is, performance during the practice and post-test were similar for the participants who imagined an object during the practice phase compared to the participants who practiced with an object. The post-test with and without an object were also similar within the same group as well as between the two groups. The results of the study provided additional evidence vision does not influence the focus of attention effect. Participants that practiced the standing long jump with a visible cone did not change the performance on the transfer test when the cone was removed. Also, participants that were instructed to direct their attention toward an imaginary cone performed just as well as participants that focused their attention on a visible cone on both the retention and transfer test. Therefore, the primary finding of the present experiment is that the focus of attention effect can be induced through the use of imagery.
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Petersamer, Matthias. "Prediction of motion trajectories based on motor imagery by a brain computer interface." Master's thesis, Pontificia Universidad Católica del Perú, 2017. http://tesis.pucp.edu.pe/repositorio/handle/123456789/11605.
Full textAbstract:
The aim of this Master's Thesis was to develop a naturally controllable BCI that can predict
motion trajectories from the imagination of motor execution. The approach to reach this aim
was to nd a correlation between movement and brain data, which can subsequently be used
for the prediction of movement trajectories only by brain signals. To nd this correlation, an
experiment was carried out, in which a participant had to do triggered movements with its right
arm to four di erent targets. During the execution of the movements, the kinematic and EEG
data of the participant were recorded. After a preprocessing stage, the velocity of the kinematic
data in x and y directions, and the band power of the EEG data in di erent frequency ranges
were calculated and used as features for the calculation of the correlation by a multiple linear
regression. When applying the resulting regression parameter to predict trajectories from EEG
signals, the best accuracies were shown in the mu and low beta frequency range, as expected.
However, the accuracies were not as high as necessary for control of an application.El objetivo de esta Tesis de Maestría fue desarrollar un interfaz cerebro computador controlable naturalmente que pueda predecir trayectorias de movimiento imaginadas. El enfoque para alcanzar este objetivo fue encontrar una correlación entre el movimiento y los datos cerebrales que puedan ser utilizados posteriormente para la predicción de las trayectorias de movimiento sólo por medio de señales cerebrales. Para encontrar esta correlación, se realizó un experimento, en cual un participante tuvo que realizar movimientos desencadenados con su brazo derecho a cuatro puntos diferentes. Durante el examen de los movimientos, se registraron los datos cinemáticos y de EEG del participante. Después de una etapa de pre-procesamiento, se calcularon las velocidades en las direcciones x y y, de los datos cinemáticos, y la potencia de la banda, de los datos EEG en diferentes rangos de frecuencia, y se utilizaron como características para el cálculo de la correlación mediante con una regresión lineal múltiple. Al aplicar el parámetro de regresión resultante para predecir trayectorias a partir de señales de EEG, las mejores precisiones estuvieron en el rango de frecuencia mu e inferior en beta, como se esperaba. Sin embargo, los resultados no fueron suficientemente precisos como para usarlas para el control de una aplicación.
Tesis
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Karnad, Vaishnavi. "A Novel P300 speller with motor imagery embedded in a traditional oddball paradigm." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2533.
Full textAbstract:
A Brain Computer Interface (BCI) provides a means, to control external devices, through the electrical activity of the brain, bypassing motor movement. Recent years have seen an increase in the application of P300 cognitive potential as a control and/or communication signal for the motor restoration in paralyzed patients, such as those in the later stages of ALS (Amyotrophic lateral sclerosis). Although many of these patients are in locked-in state i.e. where motor control is not possible, their cognition is known to remain intact. The P300 speller paradigm explored in this study relying on this cognition represented by the P300 peak potential in EEG (Electroencephalography) signals to restore communication. The conventional visual oddball paradigms used to elicit P300 potential may not be the optimum choice due to their need for precise eye-gazing, which may be challenge for many patients. This study introduces a novel paradigm with motor imagery as a secondary after-stimulus task in a traditional visual oddball paradigm for P300 Speller application. We observed increased P300 peak amplitude as well as the event-related desynchronization (ERD) associated with motor imagery in six healthy novice subjects. Acceptable detection accuracy was obtained in the five-trial averaged signals from 250 ms to 750 ms after the visual stimulation, whereby the early visual evoked potentials were excluded from classification. As an enhancement, efforts are being made to assess implementation by motor imagery embedded in an auditory oddball paradigm which would minimize the need for eye-gazing further. We can conclude from the results of this study that the proposed paradigm with motor imagery embedded in a traditional visual oddball paradigm might be a feasible option for communication restoration in paralyzed patients.
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BENEVIDES, A. B. "A Brain-computer Interface Architecture Based On Motor Mental Tasks And Music Imagery." Universidade Federal do Espírito Santo, 2013. http://repositorio.ufes.br/handle/10/9709.
Full textAbstract:
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Previous issue date: 2013-08-30This present research proposes a Brain-Computer Interface (BCI) architecture adapted to motor mental tasks and music imagery. For that purpose the statistical properties of the electroencephalographic signal (EEG) were studied, such as its probability distribution function, stationarity, correlation and signal-to-noise ratio (SNR), in order to obtain a minimal empirical and well-founded parameter system for online classification. Stationarity tests were used to estimate the length of the time windows and a minimum length of 1.28 s was obtained. Four algorithms for artifact reduction were tested: threshold analysis, EEG filtering and two Independent Component Analysis (ICA) algorithms. This analysis concluded that the algorithm fastICA is suitable for online artifact removal. The feature extraction used the Power Spectral Density (PSD) and three methods were tested for automatic selection of features in order to have a training step independent of the mental task paradigm, with the best performance obtained with the Kullback-Leibler symmetric divergence method. For the classification, the Linear Discriminant Analysis (LDA) was used and a step of reclassification is suggested. A study of four motor mental tasks and a non-motor related mental task is performed by comparing their periodograms, Event-Related desynchronization/synchronization (ERD/ERS) and SNR. The mental tasks are the imagination of either movement of right and left hands, both feet, rotation of a cube and sound imagery. The EEG SNR was estimated by a comparison with the correlation between the ongoing average and the final ERD/ERS curve, in which we concluded that the mental task of sound imagery would need approximately five times more epochs than the motor-related mental tasks. The ERD/ERS could be measured even for frequencies near 100 Hz, but in absolute amplitudes, the energy variation at 100 Hz was one thousand times smaller than for 10 Hz, which implies that there is a small probability of online detection for BCI applications in high frequency. Thus, most of the usable information for online processing and BCIs corresponds to the α/µ band (low frequency). Finally, the ERD/ERS scalp maps show that the main difference between the sound imagery task and the motor-related mentaltasks is the absence of ERD at the µ band, in the central electrodes, and the presence of ERD at the αband in the temporal and lateral-frontal electrodes, which correspond tothe auditory cortex, the Wernickes area and the Brocas area.
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Lidwall, Miranda, and Ögren Josefin Jonson. "Motorisk planering hos barn och vuxna : - associationer med motor imagery och exekutiva funktioner." Thesis, Umeå universitet, Institutionen för psykologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-159346.
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Denna studie undersökte motorisk planering hos vuxna (20-27 år) och barn i nio till tio års ålder samt dess associationer med Motor Imagery (MI), den interna representationen av en handling. Detta genom att undersöka skillnader hos barn och vuxnas förmåga att planera motoriska handlingar i form av MI och end-state comfort effekter (ESC). ESC, ett begrepp kopplat till MI, innebär en prioritering av greppbekvämlighet i slutskedet av en handling istället för i början. För att undersöka MI togs responstider, tiden det tog att avge ett svar efter stimuli presenterats, ut från den mentala rotationsuppgiften Hand Laterality Judgement Task (HLJ). För att undersöka motorisk planering fick deltagarna utföra målinriktade förflyttningar av en pinne (semicirkulära pinntestet, SPT), ett test vilket inkluderar MI och ESC. I SPT manipuleras planeringsbehovet experimentellt då greppformationskraven varieras mellan försöken. Tiden från försökets början till initiering av handledsrörelse togs ut som ett mått på planering. Vidare undersöktes motorisk planering hos vuxna och barn samt dess associationer med exekutiva funktioner (inhibering, skiftning, planering och arbetsminne). I studien deltog 15 personer, varav sju stycken barn. En experimentell design tillämpades där tester av exekutiva funktioner, SPT, HLJ och en visuell mental rotationsuppgift utfördes. Resultaten fann att barn i nio till tio års ålder skiljde sig från vuxna gällande att barnen hade längre latenstid på SPT, responstid på HLJ samt lägre responsprecision på bägge test. Ytterligare en skillnad var att de vuxna uppvisade en association mellan MI och exekutiva funktionerna, vilket inte återfanns hos barnen.This study examined motor planning in adults (20-27 years) and children nine to ten years old and its associations with motor imagery (MI), the internal representation of an action. This by examining differences in children and adults' ability to plan motor actions in the form of MI and End-state comfort effects (ESC). ESC, a concept linked to MI, involves a prioritization of grip comfort in the end of an action instead of the beginning. To examine MI, response times, the time it took to respond after stimuli were presented, were taken out from the mental rotation task Hand Laterality Judgement Task (HLJ). To examine motor planning participants performed a peg movement task (Semi-Circular Peg task, SPT) that included aspects of MI and ESC. In the SPT, the need for planning is experimentally manipulated as grip formation demands varies across trials. The time from trial onset to wrist movement initation was extracted as a measure of planning. Furthermore motor planning was examined in adults and children and its associations with executive functions (inhibition, shifting, planning and working memory). In the study 15 people participated, of which seven were children. An experimental design was applied in which tests of executive functions, SPT, HLJ and a visual mental rotation task were performed. The results found that children aged nine to ten differed from adults in that the children had longer latency time on SPT, response time on HLJ and a lower response precision on both tests. Another difference was that the adults showed an association between MI and executive functions which was not found for in the children.
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Parkkila, Christoffer. "Empirical studies of multiobjective evolutionary algorithm in classifying neural oscillations to motor imagery." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-44826.
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Brain-computer interfaces (BCIs) enables direct communication between a brain and a computer by recording and analyzing a subject’s neural activity in real-time. Research in BCI that classifies motor imagery (MI) activities are common in the literature due to its importance and applicability, e.g., stroke rehabilitation. Electroencephalography (EEG) is often used as the recording technique because its non-invasive, portable and have a relatively low cost. However, an EEG recording returns a vast number of features which must be reduced to decrease the computational time and complexity of the classifier. For this purpose, feature selection is often applied. In this study, a multiobjective evolutionary algorithm (MOEA) was used as feature selection in a high spatial and temporal feature set to (1) compare pairwise combinations of different objectives, (2) evaluate the relationship between the specific objective pair and their relation to model prediction accuracy, (3) compare multiobjective optimization versus a linear combination of the individual objectives. The results show that correlation feature selection (CFS) obtained the best performance between the evaluated objectives which were also more optimized than a linear combination of the individual objectives when classified with support vector machine (SVM).
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Oliveira, Marina Faveri de. "Efeitos do imobilismo e potencial terapêutico: do treino motor imaginário." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/47/47135/tde-08022013-145441/.
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A imobilização de membros e/ou articulações é prática utilizada na clínica no tratamento de diversas patologias, podendo variar em sua extensão e duração. Acometimentos ortopédicos comuns, como fraturas e lesões músculo-tendíneas, podem exigir como tratamento de dias a semanas de imobilização do segmento afetado. Além dos efeitos clínicos almejados, a imobilização desencadeia alterações negativas que afetam localmente o sistema musculoesquelético, mas que também trazem consequências para o sistema nervoso central (SNC) e sistema nervoso periférico. Tais consequências negativas implicam em perdas funcionais, que podem levar à dependência parcial ou completa para a realização de atividades da vida diária, como a higiene, a alimentação e a locomoção, com enormes custos individuais, familiares e sociais. É necessário, portanto, esclarecer a natureza de tais efeitos negativos e, em especial identificar o quão cedo se apresentam as alterações comportamentais e fisiológicas decorrentes do imobilismo, assim como quantificá-las e determinar a efetividade de estratégias de interferência neste processo. Neste trabalho, investigamos os efeitos de 24 horas de imobilização sobre diferentes tarefas motoras, como apertar botões, realizar a oposição do polegar em sequências variadas e fazer o alcance de alvos com o membro superior. Investigamos também, para a tarefa de oposição do polegar, o potencial terapêutico do treino motor imaginário durante o período de imobilização. Em nossos resultados, não encontramos efeitos estatísticamente significativos da imobilização sobre o comportamento motor nas tarefas pesquisadas. Adicionalmente, o treino motor imaginário na tarefa de oposição do polegar levou a uma piora no desempenho na tarefa de alcance. Esses resultados são relevantes no sentido de ressaltar que a imobilização, um recurso terapêutico importante, apresenta efeitos colaterais, mas esses não se instalam tão rapidamente quanto inicialmente hipotetizamos. É provável, ainda, que a imobilização atue de forma distinta sobre diferentes habilidades motoras, sendo umas prejudicadas com maior intensidade e precocidade do que outras. Entre as habilidades motoras afetadas pela imobilização, pode ser que encontremos, inclusive, a habilidade de imaginar cinestesicamente movimentos. O presente estudo investigou um tipo específico de treino motor imaginário, em voluntários saudáveis, submetidos a um período extremamente curto de imobilização. Possivelmente, os resultados de outros tipos de treino (variando, por exemplo, a intensidade do treino, a forma de admnistração e até mesmo a tarefa) podem ser diferentes. As sutilezas envolvidas na execução do treino motor imaginário provavelmente são a raiz da variabilidade nos resultados obtidos nos diversos experimentos da literatura. Os usos do treino motor imaginário devem, portanto, continuar a ser submetidos à experimentação, para que sua prescrição seja criteriosa e beneficie satisfatoriamente a função motora após a imobilizaçãoThe immobilization of body segments is frequently used for the treatment of orthopaedic injuries, such as fractures and soft tissue lesions. Immobilization may be as long as days or weeks, leading to several undesired side effects. The negative effects due to immobilization are felt not only in the immobilized limb, but also in the central nervous system. They lead to several functional impairments, compromising the independency of the patients in fulfilling their daily activities. Therefore, its necessary to determine the nature of such negative effects, and, specially, determine how early the functional and physiological impairments present themselves, as much as to quantify them and stabilish strategies for interference on them. In the present work, we investigated the effects of a 24-hour period of immobilization of the upper limb over several motor tasks, such as pressing buttons, oppose the thumb to the other fingers in several sequences and reaching targets. We also addressed the issue of the potential benefits of delivering a motor imagery training session, specific to the thumb opposition, during the immobilization period. Our results showed no significant effect of immobilization over the motor behavior in the evaluated tasks. Aditionally, the motor imagery training in opposing the thumb lead to an impairment on the reaching task. These results are relevant to reassure that immobilization is a safe therapeutic tool, for its side effects do not present themselves as early as hypothesized by us. Its possible, yet, that immobilization has distinct effects over different motor habilities and, in doing so, that some of the motor skills are more affected than others. It is possible that, between the motor skills affected by immobilization, we found the motor imagery hability. The present study investigated specific schedule of motor imagery training, in healthy volunteers, submited to a very short immobilization period. Its possible that other training schedules (varying the intensity, the way of administering it e even the task) might have other results then ours. The subtleties involved in motor imagery training may be the cause for the great amount of variance found in literature about it. The uses of motor imagery should be submitted to experimentation. In this way, it might be prescribed with criteria and benefit the restoration of motor function
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Ruffino, Célia. "Etude des mécanismes comportementaux et neurophysiologiques consécutifs à un entrainement par imagerie motrice." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCK027/document.
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Dans la littérature, de nombreuses recherches dans le domaine du contrôle moteur, des sciences du sport ou encore de la rééducation se sont intéressées à l’apprentissage moteur consécutif à un entrainement mental. Cependant, plusieurs mécanismes, qu’ils soient comportementaux ou neurophysiologiques, demeurent encore aujourd’hui peu étudiés. Dans notre première étude, nous avons montré qu’il était impossible de prédire la future amélioration de la performance suite à un entrainement mental aigu, sur une tâche de vitesse-précision, par la simple évaluation subjective des capacités d’imagerie chez une population jeune. Il apparait cependant essentiel de produire des images claires et précises tout au long de l’entrainement pour obtenir de meilleures performances in fine. De plus, par l’analyse fine de la performance, nos résultats ont montré, dans notre seconde étude, les véritables effets des répétitions imaginées sur la mémorisation des habiletés motrices. L’entrainement mental est également apparu efficace pour compenser le déficit de mémoire motrice rapidement observable dans la population âgée. Enfin, une troisième étude a révélé que les répétitions d’un mouvement imaginé pouvaient modifier, de façon transitoire, le codage des réseaux neuronaux impliqués dans le processus de mémoire motriceFor many years, research in motor control, sport science and rehabilitation focused on the performance improvement following mental practice. However, some mechanisms, behavioral and neurophysiological, remain insufficiently understood. In our first study, we demonstrated the impossibility to predict the future performance improvement following imagined repetitions of a speed accuracy trade-off task, with a subjective evaluation of imagery ability of young healthy individuals. However, it is essential to produce clear and vivid mental simulations throughout the training to obtain a better performance improvement. Besides, by a further analysis of performance, the results of our second study have shown the real impact of mental training on the memorization of motor skills. Motor imagery training also appeared to be effective to compensate the motor memory deficit observed in the elderly. Finally, a third study revealed that the repetitions of imagined movements could modify, temporarily, the coding of neural networks involved in the motor memory process
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Amado, Catarina Pereira. "Diving into the depth of primary motor cortex: a high-resolution investigation of the motor system using 7Tesla fMRI." Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/13161.
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Dissertação para a obtenção do Grau de Mestre em Engenharia BiomédicaHuman behaviour is grounded in our ability to perform complex tasks. While human motor function has been studied for over a century the cortical processes underlying motor behaviour are still under debate. Central to the execution of action is the primary motor cortex (M1), which has previously been considered to be responsible for the execution of movements planned in the premotor cortex, yet recent studies point to more complex roles for M1 in orchestrating motor-related information. The purpose of this project is to study the functional properties of primary motor cortex using ultra-high fMRI. The spatial resolution made possible by using a high field magnet allows us to investigate novel questions such as the existence of cortical columns, the functional organization pattern for single fingers and functional involvement of M1 in motor imagery and observation. Thirteen young healthy subjects participated in this study. Functional and anatomical high resolution images were acquired. Four functional scans were acquired for the different tasks: motor execution; motor imagery; movement observation and rest. The paradigm used was a randomized finger tapping. The images analysis was performed with the Brainvoyager QX program. Using the novel high resolution cortical grid sampling analysis tools, different cortical laminas of human M1 were examined. Our results reveal a distributed pattern (intermingled with somatotopic “hot spots”) for single fingers activity in M1. Furthermore we show novel evidence of columnar structures in M1 and show that non motor tasks such as motor imagery and action observation also activate this region. We conclude that the primary motor cortex has much more un-expected complex roles regarding the processing of movement related information, not only due to their involvement in tasks that do not imply muscle movement, but also due to their intriguing organization pattern.
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簡建顥 and Kin-ho Kan. "The effect of mental imagery in the performance and recall of a sequence of Tai Chi movements." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31257239.
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Kan, Kin-ho. "The effect of mental imagery in the performance and recall of a sequence of Tai Chi movements /." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk:8888/cgi-bin/hkuto%5Ftoc%5Fpdf?B23435884.
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Alenezi, Majid. "Motor imagery as a potential tool for improvement of musculoskeletal function in physiotherapy practice." Thesis, Bangor University, 2018. https://research.bangor.ac.uk/portal/en/theses/motor-imagery-as-a-potential-tool-for-improvement-of-musculoskeletal-function-in-physiotherapy-practice(2daf1dd3-2404-45aa-9626-cb05013a012a).html.
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Motor imagery (MI) is a cognitive simulation technique with increasing importance in psychology, sport psychology and applied therapeutic domains (Dickstein & Deutsch, 2007; Guillot & Collet, 2008; Moran, Guillot, MacIntyre, & Collet, 2012). MI can be described as executing specific actions/tasks mentally, without any bodily movement, by adopting different sensory modalities (e.g. Collet & Guillot, 2010; Cumming & Ramsey, 2008; Jackson, Lafleur, Malouin, Richards, & Doyon, 2001). In the last two decades, a considerable amount of work has been performed to introduce MI as an effective rehabilitation tool for motor function, especially in the neurorehabilitation setting (Braun et al., 2006; Dickstein & Deutsch, 2007; Malouin & Richards, 2013; Mulder, 2007; Schuster, Butler, Andrews, Kischka, & Ettlin, 2012; Zimmermann-Schlatter et al., 2008). Despite the accumulating evidence supporting the benefits of cognitive techniques (e.g. MI) for patients with various neurological conditions, relatively little attention has been paid to the effects of imagery applications on the musculoskeletal system (Pelletier, Higgins, & Bourbonnais, 2015a, 2015b; Snodgrass et al., 2014). Consequently, the general objective of this thesis is to explore the potential role of MI as a therapeutic tool to be used as an alternative or adjunct to the traditional physiotherapeutic exercise for musculoskeletal parameters. The thesis is written as a collection of research studies committed to the objective described above. Chapter 1 represents a review of the literature exploring the potential role of imagery in musculoskeletal rehabilitation. Although the review chapter shows encouraging findings from the recent literature, it reveals the need to improve and develop the existing imagery intervention protocols for muscle strength outcomes to be used as a physiotherapeutic tool. Based on this need, our thesis comprises two experimental studies examining imagery’s efficacy on maximal force production in larger muscle groups, which is relevant in physiotherapy practice. In addition, this thesis builds on the potential expansion of research activities using imagery in Arabic countries by translating the vividness movement imagery questionnaire (VMIQ-2) to the Arabic language. Chapter 2 describes outcomes of a randomised control study examining the efficacy of cognitive imagery training on hip abductor strength in healthy individuals. In the study, two newly developed imagery protocols with specific imagery modalities, namely kinaesthetic with visual (KIN+VI) and kinesthetic only (KIN), were used and compared with a control group (no practice). The results demonstrated the efficacy of the imagery intervention for increasing strength in the hip abductor muscles and emphasised superior outcomes for the combined protocol (KIN+VI) for strength gains. In addition, the study revealed the efficacy of the KIN+VI imagery intervention for improving imagery ability (vividness). Chapter 3 reports the results of the second experimental study, which examines the efficacy of imagery practice (using the KIN+VI protocol from study 1) on the maximal isometric strength and electrical activity (EMG) of hip abductors (i.e. the efficacy of the ipsilateral training effect and bilateral transfer effects) compared with exercise in healthy individuals. In this study, the results showed a significant ipsilateral increase in strength and EMG amplitude in the trained hip abductor muscles of the imagery group (KIN+VI), while the exercise group did not show considerable gains. In addition, this chapter reports a novel finding concerning a bilateral transfer effect occurring after unilateral imagery training of the tested muscle group, with no strength gains occurring following exercise training. Finally, this study shows a clear indication that the home-imagery intervention protocol should be favoured over the home-exercise training due to the higher level of commitment in the imagery group; this illustrates the possibility of using imagery practice as a self-management intervention. Chapter 4 reports on the translation and validation of the VMIQ-2 to Arabic among Arabic native speakers living in the United Kingdom and Saudi Arabia. The chapter provides information about the translation process, cognitive debriefing test and initial reliability of the VMIQ-2 Arabic version. The study used an advanced analytical procedure to evaluate factorial validity by employing Bayesian structural equation modelling (BSEM) for each country’s dataset. The findings of this study provide initial support for the newly translated VMIQ-2-A with adequate psychometric properties; hence, it represents the first imagery ability questionnaire that has been translated into Arabic. Chapter 5 provides a summary of the thesis findings and clarifies the novelty of the current thesis. In addition, it outlines the future implications of the findings from the application and research perspectives. Furthermore, this chapter addresses the strengths and limitations of the thesis. Finally, it presents the conclusion of the current work.
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O'Brien, Jonathon. "The use of motor imagery in the treatment of the hemiplegic hand in adults." Thesis, Bangor University, 2011. https://research.bangor.ac.uk/portal/en/theses/the-use-of-motor-imagery-in-the-treatment-of-the-hemiplegic-hand-in-adults(9ad9a8db-6e18-480a-9827-986b90a74495).html.
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Background: Recent work on mental practice using motor imagery (MI) in the treatment of post-stroke motor impairments. Aim: To provide evidence regarding effects of MI on hemiplegic intrinsic hand muscles. Objectives: Experiment one's objective was to identify if kinaesthetic MI (KMI) activated the hemiplegic lumbrical muscles and reduced overall movement time (MT). Experiment two's objective was to identify if KMI and visual motor imagery (VMI) had different effects on lumbrical activity and MT. Experiment three's objective was to establish if VMI or KMI provoked electromyogram (EMG) activity in the hemiplegic or intact abductor pollicis brevis (APB). Design/methodology: Experiment one used optoelectronic motion capture in a single factor independent groups design. Dependent variables (DVs) included joint magnitude, velocity and MT. Experiment two employed optoelectronic capture in a between-within design. DV s included interjoint correlation, joint magnitude and MT. Experiment three used a between-within design, measuring EMG in APB and abductor digiti minimi (ADM). DVs were EMG levels in different conditions. Participants: Experiment one involved ten adults with hemiplegia. (Mage= 74.4, SDage= 10.3). Five were male. Experiment two involved 15 adults with hemiplegia (M age = 60.6, SDage = 12.9). Six were male. Experiment three involved ten adults with hemiplegia (M age = 59.8, SD age= 10.57). Five were male. It also included ten non-hemiplegic adults (M age = 59.8, SD age = 9.09). Six were male. All were Colombian. Results: In experiment one MT was shorter for KMI (p = .031). Experiment two also showed shorter MT for KMI (p = .022) and significant negative correlation between two finger joints for VMI (p = .01), suggesting improved lumbrical activation. Experiment three found lower EMG in the hemiplegic APB following KMI (p = 0.019), compared with rest. Conclusions: KMI is more effective in reducing MT and pathologically raised EMG. VMI may improve interjoint coordination.
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Jackson, Elizabeth Helene. "An exploratory examination of the electroencephalographic correlates of aural imagery, kinesthetic imagery, music listening, and motor movement by novice and expert conductors." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345482654.
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