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Diving into the depth of primary motor cortex: a high-resolution investigation of the motor system using 7Tesla fMRI

Amado, Catarina Pereira
Fonte: Faculdade de Ciências e Tecnologia Publicador: Faculdade de Ciências e Tecnologia
Tipo: Dissertação de Mestrado
Publicado em //2014 ENG
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46.47%
Dissertação para a obtenção do Grau de Mestre em Engenharia Biomédica; Human 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...

Influence of mental practice and movement observation on motor memory, cognitive function and motor performance in the elderly

Altermann,Caroline D. C.; Martins,Alexandre S.; Carpes,Felipe P.; Mello-Carpes,Pâmela B.
Fonte: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia Publicador: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2014 EN
Relevância na Pesquisa
36.46%
BACKGROUND: With aging, it is important to maintain cognitive and motor functions to ensure autonomy and quality of life. During the acquisition of motor skills, it is necessary for the elderly to understand the purpose of the proposed activities. Physical and mental practice, as well as demonstrations, are strategies used to learn movements. OBJECTIVES: To investigate the influence of mental practice and the observation of movement on motor memory and to understand the relationship between cognitive function and motor performance in the execution of a sequence of digital movements in the elderly. METHOD: This was a cross-sectional study conducted with 45 young and 45 aged subjects. The instruments used were Mini-Mental State Examination (MMSE), Manual Preference Inventory and a Digital Motor Task (composed of a training of a sequence of movements, an interval and a test phase). The subjects were divided into three subgroups: control, mental practice and observation of movement. RESULTS: The elderly depend more strongly on mental practice for the acquisition of a motor memory. In comparing the performances of people in different age groups, we found that in the elderly, there was a negative correlation between the MMSE score and the execution time as well as the number of errors in the motor task. CONCLUSIONS: For the elderly...

Motor Planning, Imagery, and Execution in the Distributed Motor Network: A Time-Course Study with Functional MRI

Hanakawa, Takashi; Dimyan, Michael A.; Hallett, Mark
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.54%
Activation of motor-related areas has consistently been found during various motor imagery tasks and is regarded as the central mechanism generating motor imagery. However, the extent to which motor execution and imagery share neural substrates remains controversial. We examined brain activity during preparation for and execution of physical or mental finger tapping. During a functional magnetic resonance imaging at 3 T, 13 healthy volunteers performed an instructed delay finger-tapping task either in a physical mode or mental mode. Number stimuli instructed subjects about a finger-tapping sequence. After an instructed delay period, cue stimuli prompted them either to execute the tapping movement or to imagine it. Two types of planning/preparatory activity common for movement and imagery were found: instruction stimulus–related activity represented widely in multiple motor-related areas and delay period activity in the medial frontal areas. Although brain activity during movement execution and imagery was largely shared in the distributed motor network, imagery-related activity was in general more closely related to instruction-related activity than to the motor execution–related activity. Specifically, activity in the medial superior frontal gyrus...

Decreased connectivity and cerebellar activity in autism during motor task performance

Mostofsky, Stewart H.; Powell, Stephanie K.; Simmonds, Daniel J.; Goldberg, Melissa C.; Caffo, Brian; Pekar, James J.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.55%
Although motor deficits are common in autism, the neural correlates underlying the disruption of even basic motor execution are unknown. Motor deficits may be some of the earliest identifiable signs of abnormal development and increased understanding of their neural underpinnings may provide insight into autism-associated differences in parallel systems critical for control of more complex behaviour necessary for social and communicative development. Functional magnetic resonance imaging was used to examine neural activation and connectivity during sequential, appositional finger tapping in 13 children, ages 8–12 years, with high-functioning autism (HFA) and 13 typically developing (TD), age- and sex-matched peers. Both groups showed expected primary activations in cortical and subcortical regions associated with motor execution [contralateral primary sensorimotor cortex, contralateral thalamus, ipsilateral cerebellum, supplementary motor area (SMA)]; however, the TD group showed greater activation in the ipsilateral anterior cerebellum, while the HFA group showed greater activation in the SMA. Although activation differences were limited to a subset of regions, children with HFA demonstrated diffusely decreased connectivity across the motor execution network relative to control children. The between-group dissociation of cerebral and cerebellar motor activation represents the first neuroimaging data of motor dysfunction in children with autism...

Motor sequences and the basal ganglia: Kinematics, not habits

Desmurget, Michel; Turner, Robert S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 02/06/2010 EN
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36.41%
Despite a lack of definitive evidence, it is frequently proposed that the Basal Ganglia (BG) motor circuit plays a critical role in the storage and execution of movement sequences (or motor habits). To test this hypothesis directly, we inactivated the sensorimotor territory of the globus pallidus internus (sGPi, the main BG motor output) in two monkeys trained to perform overlearned and random sequences of four out-and-back reaching movements directed to visual targets. Infusion of muscimol (a GABAA agonist) into sGPi caused dysmetria and slowing of individual movements, but these impairments were virtually identical for overlearned and random sequences. The fluid predictive execution of learned sequences and the animals’ tendency to reproduce the sequence pattern in random trials was preserved following pallidal blockade. These results suggest the BG motor circuit contributes to motor execution, but not to motor sequencing or the storage of overlearned serial skills.

Altered resting-state effective connectivity of fronto-parietal motor control systems on the primary motor network following stroke

Inman, Cory S.; James, G. Andrew; Hamann, Stephan; Rajendra, Justin K.; Pagnoni, Giuseppe; Butler, Andrew J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.46%
Previous brain imaging work suggests that stroke alters the effective connectivity (the influence neural regions exert upon each other) of motor execution networks. The present study examines the intrinsic effective connectivity of top-down motor control in stroke survivors (n=13) relative to healthy participants (n=12). Stroke survivors exhibited significant deficits in motor function, as assessed by the Fugl-Meyer Motor Assessment. We used structural equation modeling (SEM) of resting-state fMRI data to investigate the relationship between motor deficits and the intrinsic effective connectivity between brain regions involved in motor control and motor execution. An exploratory adaptation of SEM determined the optimal model of motor execution effective connectivity in healthy participants, and confirmatory SEM assessed stroke survivors’ fit to that model. We observed alterations in spontaneous resting-state effective connectivity from fronto-parietal guidance systems to the motor network in stroke survivors. More specifically, diminished connectivity was found in connections from the superior parietal cortex to primary motor cortex and supplementary motor cortex. Furthermore, the paths demonstrated large individual variance in stroke survivors but less variance in healthy participants. These findings suggest that characterizing the deficits in resting-state connectivity of top-down processes in stroke survivors may help optimize cognitive and physical rehabilitation therapies by individually targeting specific neural pathway.

Brain Activation in Primary Motor and Somatosensory Cortices during Motor Imagery Correlates with Motor Imagery Ability in Stroke Patients

Confalonieri, Linda; Pagnoni, Giuseppe; Barsalou, Lawrence W.; Rajendra, Justin; Eickhoff, Simon B.; Butler, Andrew J.
Fonte: International Scholarly Research Network Publicador: International Scholarly Research Network
Tipo: Artigo de Revista Científica
Publicado em 29/12/2012 EN
Relevância na Pesquisa
36.44%
Aims. While studies on healthy subjects have shown a partial overlap between the motor execution and motor imagery neural circuits, few have investigated brain activity during motor imagery in stroke patients with hemiparesis. This work is aimed at examining similarities between motor imagery and execution in a group of stroke patients. Materials and Methods. Eleven patients were asked to perform a visuomotor tracking task by either physically or mentally tracking a sine wave force target using their thumb and index finger during fMRI scanning. MIQ-RS questionnaire has been administered. Results and Conclusion. Whole-brain analyses confirmed shared neural substrates between motor imagery and motor execution in bilateral premotor cortex, SMA, and in the contralesional inferior parietal lobule. Additional region of interest-based analyses revealed a negative correlation between kinaesthetic imagery ability and percentage BOLD change in areas 4p and 3a; higher imagery ability was associated with negative and lower percentage BOLD change in primary sensorimotor areas during motor imagery.

Enhanced Activation of Motor Execution Networks Using Action Observation Combined with Imagination of Lower Limb Movements

Villiger, Michael; Estévez, Natalia; Hepp-Reymond, Marie-Claude; Kiper, Daniel; Kollias, Spyros S.; Eng, Kynan; Hotz-Boendermaker, Sabina
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 28/08/2013 EN
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46.33%
The combination of first-person observation and motor imagery, i.e. first-person observation of limbs with online motor imagination, is commonly used in interactive 3D computer gaming and in some movie scenes. These scenarios are designed to induce a cognitive process in which a subject imagines himself/herself acting as the agent in the displayed movement situation. Despite the ubiquity of this type of interaction and its therapeutic potential, its relationship to passive observation and imitation during observation has not been directly studied using an interactive paradigm. In the present study we show activation resulting from observation, coupled with online imagination and with online imitation of a goal-directed lower limb movement using functional MRI (fMRI) in a mixed block/event-related design. Healthy volunteers viewed a video (first-person perspective) of a foot kicking a ball. They were instructed to observe-only the action (O), observe and simultaneously imagine performing the action (O-MI), or imitate the action (O-IMIT). We found that when O-MI was compared to O, activation was enhanced in the ventralpremotor cortex bilaterally, left inferior parietal lobule and left insula. The O-MI and O-IMIT conditions shared many activation foci in motor relevant areas as confirmed by conjunction analysis. These results show that (i) combining observation with motor imagery (O-MI) enhances activation compared to observation-only (O) in the relevant foot motor network and in regions responsible for attention...

Long-latency TMS-evoked potentials during motor execution and inhibition

Yamanaka, Kentaro; Kadota, Hiroshi; Nozaki, Daichi
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 12/11/2013 EN
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46.3%
Transcranial magnetic stimulation (TMS) has often been used in conjunction with electroencephalography (EEG), which is effective for the direct demonstration of cortical reactivity and corticocortical connectivity during cognitive tasks through the spatio-temporal pattern of long-latency TMS-evoked potentials (TEPs). However, it remains unclear what pattern is associated with the inhibition of a planned motor response. Therefore, we performed TMS-EEG recording during a go/stop task, in which participants were instructed to click a computer mouse with a right index finger when an indicator that was moving with a constant velocity reached a target (go trial) or to avoid the click when the indicator randomly stopped just before it reached the target (stop trial). Single-pulse TMS to the left (contralateral) or right (ipsilateral) motor cortex was applied 500 ms before or just at the target time. TEPs related to motor execution and inhibition were obtained by subtractions between averaged EEG waveforms with and without TMS. As a result, in TEPs induced by both contralateral and ipsilateral TMS, small oscillations were followed by a prominent negative deflection around the TMS site peaking at approximately 100 ms post-TMS (N100), and a less pronounced later positive component (LPC) over the broad areas that was centered at the midline-central site in both go and stop trials. However...

Differential Contribution of Bilateral Supplementary Motor Area to the Effective Connectivity Networks Induced by Task Conditions Using Dynamic Causal Modeling

Gao, Qing; Tao, Zhongping; Zhang, Mu; Chen, Huafu
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
Publicado em 01/05/2014 EN
Relevância na Pesquisa
36.59%
Functional imaging studies have indicated hemispheric asymmetry of activation in bilateral supplementary motor area (SMA) during unimanual motor tasks. However, the hemispherically special roles of bilateral SMAs on primary motor cortex (M1) in the effective connectivity networks (ECN) during lateralized tasks remain unclear. Aiming to study the differential contribution of bilateral SMAs during the motor execution and motor imagery tasks, and the hemispherically asymmetric patterns of ECN among regions involved, the present study used dynamic causal modeling to analyze the functional magnetic resonance imaging data of the unimanual motor execution/imagery tasks in 12 right-handed subjects. Our results demonstrated that distributions of network parameters underlying motor execution and motor imagery were significantly different. The variation was mainly induced by task condition modulations of intrinsic coupling. Particularly, regardless of the performing hand, the task input modulations of intrinsic coupling from the contralateral SMA to contralateral M1 were positive during motor execution, while varied to be negative during motor imagery. The results suggested that the inhibitive modulation suppressed the overt movement during motor imagery. In addition...

Functional organization and restoration of the brain motor-execution network after stroke and rehabilitation

Bajaj, Sahil; Butler, Andrew J.; Drake, Daniel; Dhamala, Mukesh
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 30/03/2015 EN
Relevância na Pesquisa
46.36%
Multiple cortical areas of the human brain motor system interact coherently in the low frequency range (<0.1 Hz), even in the absence of explicit tasks. Following stroke, cortical interactions are functionally disturbed. How these interactions are affected and how the functional organization is regained from rehabilitative treatments as people begin to recover motor behaviors has not been systematically studied. We recorded the intrinsic functional magnetic resonance imaging (fMRI) signals from 30 participants: 17 young healthy controls and 13 aged stroke survivors. Stroke participants underwent mental practice (MP) or both mental practice and physical therapy (MP+PT) within 14–51 days following stroke. We investigated the network activity of five core areas in the motor-execution network, consisting of the left primary motor area (LM1), the right primary motor area (RM1), the left pre-motor cortex (LPMC), the right pre-motor cortex (RPMC) and the supplementary motor area (SMA). We discovered that (i) the network activity dominated in the frequency range 0.06–0.08 Hz for all the regions, and for both able-bodied and stroke participants (ii) the causal information flow between the regions: LM1 and SMA, RPMC and SMA, RPMC and LM1...

Asymmetric fMRI Adaptation Reveals No Evidence for Mirror Neurons in Humans

Lingnau, Angelika; Gesierich, Benno; Caramazza, Alfonso
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.46%
Neurons in macaque ventral premotor cortex and inferior parietal lobe discharge during both the observation and the execution of motor acts. It has been claimed that these so-called mirror neurons form the basis of action understanding by matching the visual input with the corresponding motor program (direct matching). Functional magnetic resonance imaging (fMRI) adaptation can be used to test the direct matching account of action recognition by determining whether putative mirror neurons show adaptation for repeated motor acts independently of whether they are observed or executed. An unambiguous test of the hypothesis requires that the motor acts be meaningless to ensure that any adaptation effect is directly because of movement recognition/motor execution and not contextually determined inferences. We found adaptation for motor acts that were repeatedly observed or repeatedly executed. We also found adaptation for motor acts that were first observed and then executed, as would be expected if a previously seen act primed the subsequent execution of that act. Crucially, we found no signs of adaptation for motor acts that were first executed and then observed. Failure to find cross-modal adaptation for executed and observed motor acts is not compatible with the core assumption of mirror neuron theory...

Causal Influence of Articulatory Motor Cortex on Comprehending Single Spoken Words: TMS Evidence

Schomers, Malte R.; Kirilina, Evgeniya; Weigand, Anne; Bajbouj, Malek; Pulvermüller, Friedemann
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
46.18%
Classic wisdom had been that motor and premotor cortex contribute to motor execution but not to higher cognition and language comprehension. In contrast, mounting evidence from neuroimaging, patient research, and transcranial magnetic stimulation (TMS) suggest sensorimotor interaction and, specifically, that the articulatory motor cortex is important for classifying meaningless speech sounds into phonemic categories. However, whether these findings speak to the comprehension issue is unclear, because language comprehension does not require explicit phonemic classification and previous results may therefore relate to factors alien to semantic understanding. We here used the standard psycholinguistic test of spoken word comprehension, the word-to-picture-matching task, and concordant TMS to articulatory motor cortex. TMS pulses were applied to primary motor cortex controlling either the lips or the tongue as subjects heard critical word stimuli starting with bilabial lip-related or alveolar tongue-related stop consonants (e.g., “pool” or “tool”). A significant cross-over interaction showed that articulatory motor cortex stimulation delayed comprehension responses for phonologically incongruent words relative to congruous ones (i.e....

Modulation du système glutamatergique pendant l’apprentissage moteur : une étude de spectroscopie par résonance magnétique fonctionnelle

Proulx, Sébastien
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
Relevância na Pesquisa
36.43%
La présente étude avait pour but d’explorer les modulations fonctionnelles putaminales du signal de spectroscopie par résonance magnétique (SRM) combiné du glutamate et de la glutamine (Glx), ainsi que de l’acide γ-aminobutyrique (GABA) en lien avec l’apprentissage d’une séquence motrice. Nous avons émis l’hypothèse que les concentrations de Glx seraient spécifiquement augmentées pendant et après la pratique d’une telle tâche, et ce comparativement à une condition d’exécution motrice simple conçue pour minimiser l’apprentissage. La tâche d’appuis séquentiels des doigts (« finger taping task ») utilisée est connue pour induire un apprentissage moteur évoluant en phases, avec une progression initialement rapide lors de la première session d’entraînement (phase rapide), puis lente lors de sessions subséquentes (phase lente). Cet apprentissage est également conçu comme dépendant de processus « on-line » (pendant la pratique) d’acquisition et « off-line » (entre les périodes de pratique) de consolidation de la trace mnésique de l’habilité motrice. Une grande quantité de données impliquent le système de neurotransmission glutamatergique, principalement par l’action de ses récepteurs N-Méthyl-D-aspartate (NMDAR) et métabotropiques (mGluR)...

Imagining is not doing but involves specific motor commands: a review of experimental data related to motor inhibition

Guillot, Aymeric; Di Rienzo, Frank; MacIntyre, Tadhg E; Moran, Aidan; Collet, Christine
Fonte: Frontiers Publicador: Frontiers
Tipo: info:eu-repo/semantics/article; all_ul_research; ul_published_reviewed
ENG
Relevância na Pesquisa
46.38%
peer-reviewed; There is now compelling evidence that motor imagery (MI) and actual movement share common neural substrate. However, the question of how MI inhibits the transmission of motor commands into the efferent pathways in order to prevent any movement is largely unresolved. Similarly, little is known about the nature of the electromyographic activity that is apparent during MI. In addressing these gaps in the literature, the present paper argues that MI includes motor execution commands for muscle contractions which are blocked at some level of the motor system by inhibitory mechanisms. We first assemble data from neuroimaging studies that demonstrate that the neural networks mediating MI and motor performance are not totally overlapping, thereby highlighting potential differences between MI and actual motor execution.We then review MI data indicating the presence of subliminal muscular activity reflecting the intrinsic characteristics of the motor command as well as increased corticomotor excitability. The third section not only considers the inhibitory mechanisms involved during MI but also examines how the brain resolves the problem of issuing the motor command for action while supervising motor inhibition when people engage in voluntary movement during MI.The last part of the paper draws on imagery research in clinical contexts to suggest that some patients move while imagining an action...

Neural Basis of Motor Planning for Object-Oriented Actions: the Role of Kinematics and Cognitive Aspects

BOZZACCHI, CHIARA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
36.56%
The project I have carried out in these three years as PhD student pursued the aim of describing the motor preparation activity related to the object oriented actions actually performed. The importance of these studies comes from the lack of literature on EEG and complex movements actually executed and not just mimed or pantomimed. Using the term ‘complex’ here we refer to actions that are oriented to an object with the intent to interact with it. In order to provide a broader idea about the aim of the project, I have illustrated the complexity of the movements and cortical networks involved in their processing and execution. Several cortical areas concur to the plan and execution of a movement, and the contribution of these different areas changes according to the complexity, in terms of kinematics, of the action. The object-oriented action seems to be a circuit apart: besides motor structures, it also involves a temporo-parietal network that takes part to both planning and performing actions like reaching and grasping. Such findings have been pointed out starting from studies on the Mirror neuron system discovered in monkeys at the beginning of the ‘90s and subsequently extended to humans. Apart from all the speculations this discovery has opened to...

Funtional Near Infrared Spectroscopy Study of Language, Joint Attention and Motor Skills

Chaudhary, Ujwal
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
36.55%
Near infrared spectroscopy (NIRS) is an emerging non-invasive optical neuro imaging technique that monitors the hemodynamic response to brain activation with ms-scale temporal resolution and sub-cm spatial resolution. The overall goal of my dissertation was to develop and apply NIRS towards investigation of neurological response to language, joint attention and planning and execution of motor skills in healthy adults. Language studies were performed to investigate the hemodynamic response, synchrony and dominance feature of the frontal and fronto-temporal cortex of healthy adults in response to language reception and expression. The mathematical model developed based on granger causality explicated the directional flow of information during the processing of language stimuli by the fronto-temporal cortex. Joint attention and planning/ execution of motor skill studies were performed to investigate the hemodynamic response, synchrony and dominance feature of the frontal cortex of healthy adults and in children (5-8 years old) with autism (for joint attention studies) and individuals with cerebral palsy (for planning/execution of motor skills studies). The joint attention studies on healthy adults showed differences in activation as well as intensity and phase dependent connectivity in the frontal cortex during joint attention in comparison to rest. The joint attention studies on typically developing children showed differences in frontal cortical activation in comparison to that in children with autism. The planning and execution of motor skills studies on healthy adults and individuals with cerebral palsy (CP) showed difference in the frontal cortical dominance...

Funcionalidad del sistema de neuronas espejo y su implicación en los procesos de aprendizaje motor por observación

Lago Rodríguez, Ángel
Fonte: Universidade da Coruña Publicador: Universidade da Coruña
Tipo: Tese de Doutorado
SPA
Relevância na Pesquisa
36.49%
[Resumen] El descubrimiento de las denominadas neuronas espejo, a comienzos de los años 90 del siglo XX, ha dado pie a la realización de un gran número de investigaciones en las que se han utilizado técnicas de examen neurofisiológico (p.ej.: Estimulación Magnética Transcraneal) y de neuroimagen cerebral (p.ej.: Resonancia Magnética Funcional) con el objeto de explorar cuáles son las funciones que desempeñan, cuales son las propiedades de los estímulos que logran activarlas, y en qué áreas cerebrales se encuentran localizadas las neuronas espejo. Ciertos autores han planteado que este tipo especial de neuronas visuomotoras, que se activan tanto durante la ejecución, como durante la observación de acciones, permiten al ser humano comprender las intenciones y objetivos que los demás persiguen cuando ejecutan una acción. Otros autores han sugerido que el Sistema de Neuronas Espejo, formado por el conjunto de regiones corticales que responden ante la ejecución y observación de acciones, está activamente implicado en la transformación de información visual en comandos motores, lo cual ha resultado en la propuesta del Sistema de Neuronas Espejo como base del aprendizaje motor por observación. El trabajo que a continuación se presenta consta de dos estudios. En el primero se pretendió conocer cuáles son las características que un estímulo visual ha de presentar para lograr que el Sistema de Neuronas Espejo se active. Con el segundo estudio se quiso analizar el aprendizaje motor por observación y su posible relación con el Sistema de Neuronas Espejo. Para el primer estudio se llevaron a cabo dos experimentos. En el primero se estudió la modulación que sufren las interacciones cortico-corticales existentes entre la Corteza Premotora Ventral y la Corteza Motora Primaria durante la observación de acciones. Mediante un segundo experimento se analizó si la activación de representaciones motoras por parte del Sistema de Neuronas Espejo se basa en el procesamiento del objetivo de la acción observada o en la musculatura implicada en su ejecución. En el primer experimento se ha probado que la conectividad entre la Corteza Premotora Ventral y la Corteza Motora Primaria se modula durante la observación de acciones ejecutadas por otro individuo...

Neurophysiologische Korrelate beim mentalen Training motorischer Bewegungen : Ein Vergleich zwischen professionellen Musikern und Amateuren; Neural correlates during mental training of motor execution : a comparison between professional musicians and amateurs

Scheler, Gabriela
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
DE_DE
Relevância na Pesquisa
46.28%
In dieser Studie wurden die unterschiedlichen fMRI Aktivierungen kortikaler und subkortikaler Areale von professionellen Geigern und Amateuren während mentalen Trainings einer Finger-Tapping-Sequenz untersucht, die den ersten 16 Takten des Soloparts aus Mozarts Violinkonzert in G-Dur entsprach. Da bei professionellen Geigern wegen ihres langjährigen Trainings und ihrer Erfahrung im mentalen Training eine andere kortikale Repräsentation der Bewegungsmuster vorausgesetzt werden kann, wurde angenommen, dass sich ihre Aktivierungsmuster von denen der Amateure unterscheiden. Um sicher zu gehen, dass die Finger nicht bewegt wurden, wurde vor und während der Messung ein Elektromyogramm der Unterarmmuskulatur beider Arme abgeleitet. Die Vorstellungsaufgabe zeigte in beiden Gruppen eine Erhöhung der kortikalen Aktivierung in supplementär- und prämotorischen, lateralen zerebellären, superior parietalen Regionen. Bei den Profis zeigten sich wenige fokussierte Areale, die insgesamt einem Zugriff auf erlernte und automatisierte Bewegungsprogramme entsprachen (linker PMC, SMA, linkes posteriores Zerebellum, bilateral superior und links inferior parietal, rechts superior frontal, links anterior temporal). Langjähriges musikalisches motorisches Training sowie Erfahrung im mentalen Training gehen anscheinend mit erhöhter neuronaler Effizienz einher. Die Amateure hingegen zeigten weit verstreute Aktivierungen in Arealen...

Alpha absolute power: motor learning of practical pistol shooting

Domingues,Clayton Amaral; Machado,Sergio; Cavaleiro,Emerson Garcia; Furtado,Vernon; Cagy,Mauricio; Ribeiro,Pedro; Piedade,Roberto
Fonte: Academia Brasileira de Neurologia - ABNEURO Publicador: Academia Brasileira de Neurologia - ABNEURO
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
Relevância na Pesquisa
46.3%
The present study aimed at investigating changes in behavior (shooting precision) and electrophysiological variables (absolute alpha power) during the motor learning of practical pistol shooting. The sample was composed of 23 healthy subjects, right-handed, male, between 18 and 20 years of age. The task consisted of four learning blocks. A One-way ANOVA with repeated measures and a post hoc analysis were employed to observe modifications on behavioral and electrophysiological measures (p<0.05). The results showed significative differences between blocks according to motor learning, and a significant improvement in shooting's accuracy from both blocks. It was observed a decrease in alpha power in all electrodes examined during task execution when compared with baseline and learning control blocks. The findings suggest that alpha power decreases as the function of the motor learning task when subjects are engaged in the motor execution.