Name: testing tactile masking between the forearms
Uploaded: 2016-02-10T15:00:00.000+00:00
Duration: 8 min 5 s
Description: Watch this Scientific Journal Video about Testing Tactile Masking between the Forearms at JoVE.com

LRH foi apoiado pela Ciências e Engenharia do Conselho de Pesquisa Natural (NSERC) do Canadá. SD foi parcialmente financiado a partir do NSERC CRIAR programa.

Todos os experimentos foram aprovados pelo conselho Iorque Ética e todos os participantes assinaram formulários de consentimento informado. Os experimentos foram realizados em conformidade com o Tratado de Helsínquia. 1. estímulos <ol><li> Estímulo Detecção tácteis <ol><li> Use um contator (1,17 &quot;de diâmetro e 0,30&quot; de espessura) para entregar estímulos táteis de 250 Hz vibração para 100 ms. Usando um contator construído para o efeito fornece uma relação linear entre a quantidade de viagem e a tensão aplicada. </li><li> Controlar a entrega de estímulo tátil com uma placa de som de 64 bits. <ol><li> Para conduzir o contator, tratá-lo como um alto-falante. Ligue um amplificador de áudio estéreo para uma placa de som de computador aparelho de som de 64 bits. Ligue o contator a uma das saídas do amplificador (por exemplo, o &quot;alto-falante deixado de fora&quot;). Ligue o segundo canal (por exemplo, o &quot;alto-falante direito out &#39;) do amplificador a um altifalante regular para fornecer sinais auditivos ao participant. </li><li> No código de computador que está a controlar o experimento, gerar a forma de onda que vai ser usada para fazer vibrar o contator (por exemplo, uma onda sinusoidal de 250 Hz com uma duração de 100 ms), e outra forma de onda para o sinal auditivo (por exemplo, uma onda sinusoidal de 3000 Hz com uma duração de 100 mseg). Veja Exemplo de código 1 no arquivo de código suplementar. </li><li> Colocar cada uma destas duas formas de onda em uma matriz bidimensional. Para a matriz contator colocar o sinal na primeira dimensão e definir a segunda dimensão para todos os zeros. Para o arranjo de som colocar o sinal na segunda dimensão e definir o primeiro para todos os zeros. Jogar a matriz apropriada para a placa de som no ponto apropriado no programa. Veja Exemplo de código 1 no arquivo de código suplementar para uma demonstração de como isso é feito. </li></ol></li><li> Fixe o contator a uma cinta com um produto de fixação mecânica baseada. </li></ol></li><li> mascaramento de estímulo <ol><li> Fornecer o estímulo mascarando por um elétrico, hand-held (diâmetro 4 cm; 83 Hz quando configurado em &quot;baixa&quot;) vibrador. </li><li> Com base nas áreas onde a máscara está para ser testada, seleccionar os locais em que o estímulo de mascaramento vai ser aplicado. </li></ol></li></ol> 2. Configuração e Desenho Experimental <ol><li> Organize o computador e equipamentos em uma mesa, com uma cadeira em frente a ela, para o experimentador. </li><li> Configurar uma tabela na qual os participantes descansar o braço (teste) para a esquerda. Coloque uma cadeira para o lado direito da tabela. Coloque um suporte de apoio de braços ao lado da cadeira em que os participantes descansar seu cotovelo (braço mascarando) direita. Adicionar amortecimento para a mesa e apoio de braço para o conforto. </li><li> Organizar um alto-falante em uma superfície isolada mecanicamente. Organizar pedais (ligado aos botões esquerdo e direito de um rato de computador), de modo que os pés do participante vai descansar confortavelmente sobre eles (Figura 1). </li><li> Escolha os parâmetros do estudo, incluindo o número apropriado de ensaios necessáriospara obter uma estimativa confiável do limiar (tipicamente, entre 40-50 ensaios) e o número de blocos em que o experimento é para ser dividido (por exemplo, dois blocos de 20-25 ensaios por condição). </li><li> Adicione uma lista de ordem em que vai ser executado nas condições. Use essa lista para determinar onde para manter o estímulo de máscara para cada bloco. </li><li> Digite o número de tentativas diretamente no código de programa de computador (por exemplo, ntrials = 25; Ver arquivo de código Suplementar). Assegurar que cada bloco não é mais de 10 min para manter a atenção. </li><li> Programar uma tarefa de detecção táctil de dois alternativa de escolha forçada 11, no qual estímulo intensidade é controlada com uma escada psicofísica procedimento psicométrica adaptativa Bayesian 12. <ol><li> Para cada ensaio, apresentam dois intervalos de 1 segundo, marcado por três bips (5 kHz, 3 kHz e 5 kHz, a duração de 100 ms), com o estímulo táctil apresentada no meio de um dos intervalos. Ter o i participantendicate em que intervalo o estímulo foi apresentado por meio de pedais (da esquerda para a primeira, à direita para a segunda). Veja Exemplo de código 2, que mostra como os intervalos são executados e marcou. Nota: A pontuação de computador a resposta como &quot;correta&quot; ou &quot;errado&quot; ea escadaria adaptativa escolhe o próximo valor a ser apresentado em conformidade. Nota: Este método consiste em determinar um valor limiar para a detecção da vibração no local de teste. </li></ol></li></ol><img alt="figura 1" src="/files/ftp_upload/53733/53733fig1.jpg" /> Figura 1. Projeto Experimental. Esta figura mostra a configuração da experiência e dos materiais utilizados. Veja o texto para mais detalhes. 3. Procedimento Experimental <ol><li> Obter o consentimento informado por escrito. Assentar o participante na cadeira com os pés descansando confortavelmente sobre os pedais de resposta e explicar o procedimento experimental. &lt;/ Li&gt; <li> Medir e registar o comprimento da superfície dorsal do antebraço esquerdo. Aplicar a tira, de modo a contator está posicionado no meio do braço a meio caminho entre o ângulo interior do cotovelo e pulso do vinco. </li><li> Enrole uma bandagem tensor frouxamente em torno do braço várias vezes para manter o contator no lugar. </li><li> Instrua os participantes a colocar seu braço esquerdo sobre a mesa e descansar seu cotovelo direito no braço. Vendar o participante para impedi-los olhando para o estímulo ou mascarar localização e instruí-los a olhar para a frente durante todo o experimento. </li><li> Comece com um bloco de 20 provas práticas (sem o estímulo de máscara), a fim de familiarizar os participantes com a tarefa de detecção tátil e para permitir que eles se familiarizar com os estímulos táteis. </li><li> Após as provas práticas, começar a experiência, executando os blocos de condições em uma ordem aleatória, contrabalançado. Antes de iniciar cada bloco, garantir que os braços e as Stimu mascarandolus estão nas posições corretas. <ol><li> Para cada condição, mantenha o estímulo mascarando no site escolhido, referindo-se à lista de condições feitas anteriormente. Atravessar fora cada condição, uma vez que é executado. Segure o estímulo mascarando ao longo de cada bloco de tentativas de coleta de dados mantendo a pressão aproximadamente constante. O estímulo mascaramento pode ser aplicado através da roupa fina. </li><li> Execute o programa experimental que será executado através de um determinado número de tentativas como previamente selecionados. Introduzir um período de descanso de 2 min após cada bloco curto de ensaios. Depois de um determinado bloco de tentativas é concluído, selecione o próximo local para o estímulo de máscara e execute o programa novamente. Repita até que todos os testes sejam concluídos. </li></ol></li></ol> Análise 4. Dados <ol><li> Para visualizar e confirmar a estimativa do valor limiar devolvido pelo programa escadaria adaptativa 12, ajustar os dados dos participantes com um Gaussian acumulada A fórmula para um Gaussian cumulativo(Sigmóide), que vai de 50% (nível acaso - igual número de 0s - errado e 1&#39;s- correto) a 100% (todo o 1, todas as corretas) é: probabilidade de uma resposta correta = 0,5 + 0,5 / (1 + exp (- (x-x0) / std)) onde X é o valor de intensidade testado, x0 é o valor limiar de 75%, std e é o desvio padrão de estimativa. Esta fórmula pode ser ajustada aos dados usando o software de ajuste de curva e o valor x0 resultante em comparação com o valor escada adaptativa. <ol><li> Assegure-se que a curva vai entre 50% (desempenho acaso) e 100%. Realizar análises estatísticas (por exemplo, t-testes ou ANOVAs) sobre os valores limiar de 75% obtidos em cada condição do experimento (por exemplo, entre os diferentes locais de mascaramento) para determinar se existem diferenças entre as condições testadas. </li></ol></li><li> A fim de identificar os valores aberrantes, calcular a média e o desvio padrão para uma dada condição. Compare a pontuação de cada participante com a média eSe uma pontuação individual é mais do que 2 desvio padrão que significa, em seguida, considerar este resultado como um outlier e removê-lo da análise. critérios alternativos podem ser utilizados se desejado. </li><li> Para padronizar os valores da intensidade das tactors (que são em unidades arbitrárias), convertê-los em decibéis em relação aos limiares de controlo (medido após o estímulo de mascaramento é aplicada ao local de controlo, por exemplo, o ombro). Use esta fórmula: DB = 10 x log 10 (valor limite valor limite / controle). </li></ol>

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Os autores declaram que não têm interesses financeiros concorrentes.

Aqui, um protocolo detalhado para mascarar táctil contralateral é descrito e os resultados anteriormente publicados utilizando a técnica para testar limiares de detecção tácteis são mostrados. A vantagem deste método é que os limiares são medidos usando uma técnica psicofisicamente rigorosa. O processo em duas alternativas de escolha forçada (2AFC) é relativamente insensível à polarização de resposta e, por conseguinte, a partir de efeitos de atenção. O procedimento de escada adaptativa para afiar den...

mascaramento tátil é onde um estímulo táctil em um local sobre o corpo altera a percepção de um toque em outro local. Esta é uma técnica pioneira por von Bekesy 1 para revelar interacções localização, especialmente inibição lateral, entre as áreas da pele que estão adjacentes na superfície do corpo. Enquanto mascaramento táctil tem sido estudado extensivamente ao longo dos anos, a pesquisa investigou principalmente mascaramento tátil ipsilateral usando estimulação elétrica 2, 3, 4 pressão e estimulação vibrotátil 5, 6. Em contraste, poucos estudos têm olhou para mascarar tátil contralateral em que os locais de máscara e de sonda pode ser afastada. De longo alcance efeitos de encobrimento táteis foram mostrados entre os pontos de espelho-simétrica na mão e no braço 5, 7-9, mas estes estudos têm sido em grande parte restrita a olhar para as mãos e os dedos 7, 10, com mais extensas partes do corpo inteiro sendo largamente ignorado. Um golo de tais experiências de mascaramento de longo alcance é indicar como componentes de representação do corpo no cérebro pode ser funcionalmente ligadas. Aqui, o fenômeno da táctil mascaramento de longo alcance é explorado por investigar como a vibração aplicada a um antebraço pode afetar limiares de sensibilidade tátil no antebraço oposto. Limiar refere-se ao estímulo mínima que é necessária para detectar um estímulo. Nós definimos esta como a intensidade com que o estímulo é detectado 75% do tempo. Utilizou-se uma técnica de máscara táctil em que a sensibilidade táctil (o recíproco de limiar) em um antebraço é medida na presença de um estímulo de vibração (a máscara) na outra parte do corpo. Mascaramento eficaz é revelada por um aumento do limiar de detecção ou seja, uma redução na sensibilidade. A técnica pode ser usada em conjunto com outras manipulações tal como variando a posição dos membros óR movimento para explorar os seus efeitos sobre a eficácia de mascaramento. Aqui usamos estímulos por vibração como o estímulo de mascaramento. A vantagem disto é que a frequência e, portanto, o tipo de receptor que estimula pode ser controlada. A técnica poderia ser estendido para olhar para a dor utilizando estímulos elétricos como a sonda ou máscara ou ambos. Além disso, qualquer local pode ser utilizado como o local de mascaramento que permite a investigação de sítios acupunctura por exemplo.

<table><tbody><tr><td>C-2 tactor</td><td>ATAC Technology; Engineering Acoustics, Inc.</td><td></td><td>http://www.atactech.com/PR_tactors.html</td></tr><tr><td>Magic Wand</td><td>Hitachi</td><td></td><td>http://magicwandoriginal.com/magic-wand-original/</td></tr><tr><td>FC5 Foot Pedals</td><td>Yamaha Corporation</td><td></td><td>http://ca.yamaha.com/en/products/music-production/accessories/footpedals/fc5/?mode=model</td></tr><tr><td>MATLAB</td><td>The Mathworks, Inc.</td><td></td><td>http://www.mathworks.com/products/matlab/</td></tr><tr><td>Velcro</td><td>Velcro Industries B.V.</td><td></td><td>http://www.velcro.com/</td></tr></tbody></table>

testing tactile masking between the forearms

Masking, in which one stimulus affects the detection of another, is a classic technique that has been used in visual, auditory, and tactile research, usually using stimuli that are close together to reveal local interactions. Masking effects have also been demonstrated in which a tactile stimulus alters the perception of a touch at a distant location. Such effects can provide insight into how components of the body's representations in the brain may be linked. Occasional reports have indicated that touches on one hand or forearm can affect tactile sensitivity at corresponding contralateral locations. To explore the matching of corresponding points across the body, we can measure the spatial tuning and effect of posture on contralateral masking. Careful controls are required to rule out direct effects of the remote stimulus, for example by mechanical transmission, and also attention effects in which thresholds may be altered by the participant's attention being drawn away from the stimulus of interest. The use of this technique is beneficial as a behavioural measure for exploring which parts of the body are functionally connected and whether the two sides of the body interact in a somatotopic representation. This manuscript describes a behavioural protocol that can be used for studying contralateral tactile masking.

As análises dos dados foi relatado no 13. Sensibilidade táctil (expressos em relação aos limiares medidos na condição de controlo) no antebraço foi significativamente reduzida (limiares foram significativamente aumentadas) quando a estimulação vibrotátil mascaramento foi aplicado para o braço oposto (Figura 2A), o que demonstra um efeito de mascaramento contralateral entre antebraços. O efeito depende da posição do estímulo mascaramento no braç...

Watch this Scientific Journal Video about Testing Tactile Masking between the Forearms at JoVE.com

Testing Tactile Masking between the Forearms

Teste Tactile Masking entre os antebraços

Here we explore contralateral tactile masking between the forearms in which tactile detection thresholds are modulated by vibration applied to a remote site. The details of which remote sites have an effect can tell us about how the body is represented in the brain.

Masking, in which one stimulus affects the detection of another, is a classic technique that has been used in visual, auditory, and tactile research, ...

testing-tactile-masking-between-the-forearms

Universidad San Sebastian

Research

JoVE Journal

Behavior

6.3K visualizações.  York University. Here we explore contralateral tactile masking between the forearms in which tactile detection thresholds are modulated by vibration applied to a remote site. The details of which remote sites have an effect can tell us about how the body is represented in the brain. 

Vídeo: Testing Tactile Masking between the Forearms

Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects

Tests that allow the precise determination of psychophysical thresholds for vibration and grating orientation provide valuable information about mechanosensory function that are relevant for clinical diagnosis as well as for basic research. Here, we describe two psychophysical tests designed to determine the vibration detection threshold (automated system) and tactile spatial acuity (handheld device). Both procedures implement a two-interval forced-choice and a transformed-rule up and down experimental paradigm. These tests have been used to obtain mechanosensory profiles for individuals from distinct human cohorts such as twins or people with sensorineural deafness.

Here, we present protocols to determine vibration detection thresholds and tactile acuity using psychophysical methods in man.

Medição do limiar de detecção de vibração e tátil Spatial Acuity em Seres Humanos

Tests that allow the precise determination of psychophysical thresholds for vibration and grating orientation provide valuable information about ...

Comportamento

Creating Virtual-hand and Virtual-face Illusions to Investigate Self-representation

Studies investigating how people represent themselves and their own body often use variants of &#34;ownership illusions&#34;, such as the traditional rubber-hand illusion or the more recently discovered enfacement illusion. However, these examples require rather artificial experimental setups, in which the artificial effector needs to be stroked in synchrony with the participants&#39; real hand or face&#8212;a situation in which participants have no control over the stroking or the movements of their real or artificial effector. Here, we describe a technique to establish ownership illusions in a setup that is more realistic, more intuitive, and of presumably higher ecological validity. It allows creating the virtual-hand illusion by having participants control the movements of a virtual hand presented on a screen or in virtual space in front of them. If the virtual hand moves in synchrony with the participants&#39; own real hand, they tend to perceive the virtual hand as part of their own body. The technique also creates the virtual-face illusion by having participants control the movements of a virtual face in front of them, again with the effect that they tend to perceive the face as their own if it moves in synchrony with their real face. Studying the circumstances that illusions of this sort can be created, increased, or reduced provides important information about how people create and maintain representations of themselves.

Here, we describe virtual-hand and virtual-face illusion paradigms that can be used to study body-related self-perception/-representation. They have already been used in various studies to demonstrate that, under specific conditions, a virtual hand or face can be incorporated into one&#39;s body representation, suggesting that body representations are rather flexible.

Criando ilusões de mãos e rostos virtuais para investigar a autorrepresentação

Studies investigating how people represent themselves and their own body often use variants of &#34;ownership illusions&#34;, such as the traditional ...

A Simple Non-invasive Method for Temporary Knockdown of Upper Limb Proprioception

Proprioception may be the least well measured of all contributors to the neural control of movement. New precise, reliable measures of proprioception are needed for clinical diagnosis of impairment, and to measure outcomes of proprioceptive training. The purpose of this simple, non-invasive method is to temporarily knockdown upper limb proprioception in healthy adults, to an extent that would be useful in the development and testing of upper limb proprioception measures. Knockdown models have two main advantages over studying humans with impaired proprioception: participant availability and the ability to control the extent of impairment across participants. Current published methods of temporary proprioception knockdown of the upper limb, such as ischemic nerve blocks and cryotherapy, are invasive, impractical, or uncomfortable for the participant. Here, vibration over the ulnar groove was used to reduce upper limb proprioception. High frequency vibration may reduce proprioceptive acuity by inhibiting pacinian corpuscle-induced input. The effect of vibration used in this protocol was confirmed using two quantitative measures. This method was simple to administer, comfortable for participants, and practical.

The goal of this protocol is to demonstrate a practical method to temporarily interfere with proprioception in the upper limb of healthy humans.

Um método não-invasivo simples para Knockdown temporária de propriocepção do membro superior

Proprioception may be the least well measured of all contributors to the neural control of movement. New precise, reliable measures of proprioception are ...

Using Facial Electromyography to Assess Facial Muscle Reactions to Experienced and Observed Affective Touch in Humans

"Affective" touch is believed to be processed in a manner distinct from discriminatory touch and to involve activation of C-tactile (CT) afferent fibers. Touch that optimally activates CT fibers is consistently rated as hedonically pleasant. Patient groups with impaired social-emotional functioning also show disordered affective touch ratings. However, relying on self-reported ratings of touch has many limitations, including recall bias and communication barriers. Here, we describe a methodological approach to study affective responses to touch via facial electromyography (EMG) that circumvents the reliance on self-report ratings. Facial EMG is an objective, quantitative, and non-invasive method to measure facial muscle activity indicative of affective responses. Responses can be assessed across healthy and patient populations without the need for verbal communication. Here, we provide two separate datasets demonstrating that CT-optimal and non-optimal touch elicit distinct facial muscle reactions. Moreover, facial EMG responses are consistent across stimulus modalities, e.g. tactile (experienced touch) and visual (observed touch). Finally, the temporal resolution of facial EMG can detect responses on timescales that supersede that of verbal reporting. Together, our data suggest that facial EMG is a suitable methodology for use in affective tactile research that can be used to supplement, or in some cases, supplant, existing measures.

We describe a protocol to assess facial muscle activity in response to experienced and observed tactile stimulation using facial electromyography.

Usando eletromiografia Facial para avaliar as reações do músculo Facial toque afetivo experientes e observados em seres humanos

"Affective" touch is believed to be processed in a manner distinct from discriminatory touch and to involve activation of C-tactile (CT) afferent fibers. ...

Applying Incongruent Visual-Tactile Stimuli during Object Transfer with Vibro-Tactile Feedback

The application of incongruent sensory signals that involves disrupted tactile feedback is rarely explored, specifically with the presence of vibrotactile feedback (VTF). This protocol aims to test the effect of VTF on the response to incongruent visual-tactile stimuli. The tactile feedback is acquired by grasping a block and moving it across a partition. The visual feedback is a real-time virtual presentation of the moving block, acquired using a motion capture system. The congruent feedback is the reliable presentation of the movement of the block, so that the subject feels that the block is grasped and see it move along with the path of the hand. The incongruent feedback appears as the movement of the block diverts from the actual movement path, so that it seems to drop from the hand when it is actually still held by the subject, thereby contradicting the tactile feedback. Twenty subjects (age 30.2 &#177; 16.3) repeated 16 block transfers, while their hand was hidden. These were repeated with VTF and without VTF (total of 32 block transfers). Incongruent stimuli were presented randomly twice within the 16 repetitions in each condition (with and without VTF). Each subject was asked to rate the difficulty level of performing the task with and without the VTF. There were no statistically significant differences in the length of the hand paths and durations between transfers recorded with congruent and incongruent visual-tactile signals &#8211; with and without the VTF. The perceived difficulty level of performing the task with the VTF significantly correlated with the normalized path length of the block with VTF (r = 0.675, p = 0.002). This setup is used to quantify the additive or reductive value of VTF during motor function that involves incongruent visual-tactile stimuli. Possible applications are prosthetics design, smart sport-wear, or any other garments that incorporate VTF.

We present a protocol to apply incongruent visual-tactile stimuli during an object transfer task. Specifically, during block transfers, performed while the hand is hidden, a virtual presentation of the block shows random occurrences of false block drops. The protocol also describes adding vibrotactile feedback while performing the motor task.

Aplicando estímulos visuais-táteis incongruentes durante a transferência de objetos com feedback Vibro-tátil

The application of incongruent sensory signals that involves disrupted tactile feedback is rarely explored, specifically with the presence of vibrotactile ...

A Tactile Automated Passive-Finger Stimulator (TAPS)

Although tactile spatial acuity tests are used in both neuroscience research and clinical assessment, few automated devices exist for delivering controlled spatially structured stimuli to the skin. Consequently, investigators often apply tactile stimuli manually. Manual stimulus application is time consuming, requires great care and concentration on the part of the investigator, and leaves many stimulus parameters uncontrolled. We describe here a computer-controlled tactile stimulus system, the Tactile Automated Passive-finger Stimulator (TAPS), that applies spatially structured stimuli to the skin, controlling for onset velocity, contact force, and contact duration. TAPS is a versatile, programmable system, capable of efficiently conducting a variety of psychophysical procedures. We describe the components of TAPS, and show how TAPS is used to administer a two-interval forced-choice tactile grating orientation test.
Corresponding Author: Daniel Goldreich

A Tactile Automated Passive-Finger Stimulator TAPS

We describe a computer-controlled device for investigating the sense of touch: the Tactile Automated Passive-finger Stimulator (TAPS). We describe the components of TAPS, and show how TAPS is used to administer a two-interval forced-choice tactile grating orientation test.

A Tátil Estimulador passiva-Dedo automatizada (TAPS)

Although tactile spatial acuity tests are used in both neuroscience research and clinical assessment, few automated devices exist for delivering ...

Biologia

A Standardized Method for Measurement of Elbow Kinesthesia

Proprioception is an important component of controlled movement. The threshold to detection of passive movement (TDPM) is a commonly used method for quantifying the proprioceptive submodality of kinesthesia in research settings. The TDPM paradigm has been found to be valid and reliable; however, the equipment and methods used for TDPM vary between studies. In particular, the research laboratory apparatuses for producing passive movement of an extremity are often custom designed by individual laboratories or inaccessible due to high cost. There is a need for a standardized, valid, and reliable method for measuring TDPM using readily available equipment. The purpose of this protocol is to provide a standardized method for measurement of TDPM at the elbow that is economical, easy to administer, and that produces quantitative results for measurement purposes in research-based settings. This method was tested on 20 healthy adults without neurological impairment, and eight adults with chronic stroke. The results obtained suggest this method is a reliable way to quantify elbow TDPM in healthy adults, and provides initial support for validity. Researchers seeking a balance between equipment affordability and measurement precision are most likely to find this protocol of benefit.

Here, we present a standardized method for measurement of elbow passive kinesthesia using the threshold to detection of passive movement (TDPM) that is appropriate for a research setting.

Um método padronizado para medição da cinestésia do cotovelo

Proprioception is an important component of controlled movement. The threshold to detection of passive movement (TDPM) is a commonly used method for ...

Non-Invasive Modulation and Robotic Mapping of Motor Cortex in the Developing Brain

Mapping the motor cortex with transcranial magnetic stimulation (TMS) has potential to interrogate motor cortex physiology and plasticity but carries unique challenges in children. Similarly, transcranial direct current stimulation (tDCS) can improve motor learning in adults but has only recently been applied to children. The use of tDCS and emerging techniques like high&#8211;definition tDCS (HD-tDCS) require special methodological considerations in the developing brain. Robotic TMS motor mapping may confer unique advantages for mapping, particularly in the developing brain. Here, we aim to provide a practical, standardized approach for two integrated methods capable of simultaneously exploring motor cortex modulation and motor maps in children. First, we describe a protocol for robotic TMS motor mapping. Individualized, MRI-navigated 12x12 grids centered on the motor cortex guide a robot to administer single-pulse TMS. Mean motor evoked potential (MEP) amplitudes per grid point are used to generate 3D motor maps of individual hand muscles with outcomes including map area, volume, and center of gravity. Tools to measure safety and tolerability of both methods are also included. Second, we describe the application of both tDCS and HD-tDCS to modulate the motor cortex and motor learning. An experimental training paradigm and sample results are described. These methods will advance the application of non-invasive brain stimulation in children.

We demonstrate protocols for the modulation (tDCS, HD-tDCS) and mapping (robotic TMS) of the motor cortex in children.

Modulação não invasiva e mapeamento robótico do córtex motor no cérebro em desenvolvimento

Mapping the motor cortex with transcranial magnetic stimulation (TMS) has potential to interrogate motor cortex physiology and plasticity but carries ...

Neurociência

Capturing Dynamic Finger Gesturing with High-resolution Surface Electromyography and Computer Vision

Finger gestures are a critical element in human communication, and as such, finger gesture recognition is widely studied as a human-computer interface for state-of-the-art prosthetics and optimized rehabilitation. Surface electromyography (sEMG), in conjunction with deep learning methods, is considered a promising method in this domain. However, current methods often rely on cumbersome recording setups and the identification of static hand positions, limiting their effectiveness in real-world applications. The protocol we report here presents an advanced approach combining a wearable surface EMG and finger&#160;tracking system to capture comprehensive data during dynamic hand movements. The method records muscle activity from soft printed electrode arrays (16 electrodes) placed on the forearm as subjects perform gestures in different hand positions and during movement. Visual instructions prompt subjects to perform specific gestures while EMG and finger positions are recorded. The integration of synchronized EMG recordings and finger tracking data enables comprehensive analysis of muscle activity patterns and corresponding gestures. The reported approach demonstrates the potential of combining EMG and visual tracking technologies as an important resource for developing intuitive and responsive gesture recognition systems with applications in prosthetics, rehabilitation, and interactive technologies. This protocol aims to guide researchers and practitioners, fostering further innovation and application of gesture recognition in dynamic and real-world scenarios.

The paper presents a comprehensive protocol for simultaneously recording hand-electromyography (EMG) and visual finger tracking during natural finger gesturing. The visual data is designed to serve as the ground truth for the development of accurate EMG-based computational models for finger gesture recognition.

Capturando gestos dinâmicos com os dedos com eletromiografia de superfície de alta resolução e visão computacional

Finger gestures are a critical element in human communication, and as such, finger gesture recognition is widely studied as a human-computer interface for ...

Bioengenharia

Assessing Corticospinal Excitability During Goal-Directed Reaching Behavior

Reaching is a widely studied behavior in motor physiology and neuroscience research. While reaching has been examined using a variety of behavioral manipulations, there remain significant gaps in the understanding of the neural processes involved in reach planning, execution, and control. The novel approach described here combines a two-dimensional reaching task with transcranial magnetic stimulation (TMS) and concurrent electromyography (EMG) recording from multiple muscles. This method allows for the noninvasive detection of corticospinal activity at precise time points during the unfolding of reaching movements. The example task code includes a delayed response reaching task with two possible targets displayed &#177; 45&#176; off the midline. Single pulse TMS is delivered on the majority of task trials, either at the onset of the preparatory cue (baseline) or 100 ms prior to the imperative cue (delay). This sample design is suitable for investigating changes in corticospinal excitability during reach preparation. The sample code also includes a visuomotor perturbation (i.e., cursor rotation of &#177; 20&#176;) to investigate the effects of adaptation on corticospinal excitability during reach preparation. The task parameters and TMS delivery can be adjusted to address specific hypotheses about the state of the motor system during reaching behavior. In the initial implementation, motor evoked potentials (MEPs) were successfully elicited on 83% of TMS trials, and reach trajectories were recorded on all trials.

Reaching is a fundamental skill that allows humans to interact with the environment. Several studies have aimed to characterize reaching behavior using a variety of methodologies. This paper offers an open-source application of transcranial magnetic stimulation to assess the state of corticospinal excitability in humans during reaching task performance.

Avaliando a excitabilidade corticoespinhal durante o comportamento de alcance direcionado a objetivos

Reaching is a widely studied behavior in motor physiology and neuroscience research. While reaching has been examined using a variety of behavioral ...