Name: transcranial magnetic stimulation for investigating causal brain-behavioral relationships and their time course
Uploaded: 2014-07-18T13:00:00.000+00:00
Duration: 11 min 33 s
Description: Watch this Scientific Journal Video about Transcranial Magnetic Stimulation for Investigating Causal Brain-behavioral Relationships and their Time Course at JoVE.com

作者没有确认。

这个协议被用于神经正常人类志愿者无创性脑刺激批准伦敦大学学院伦理审查委员会（第249/001）。 1，创建TMS方案在认知神经科学的几乎所有的TMS实验使用的双相刺激与数字8字形的成形线圈一起使用。这提供了能够提供脉冲的快速列车的能力（&gt; 1赫兹），并针对一个皮质站点尽可能精确。它可以使用单相性刺激35或不同的线圈形状36，但是这里的标准配置被应用。 <ol><li>选择一个频率刺激和持续时间。 注:在认知神经科学的一个常见的选择是使用10赫兹刺激发病的刺激37-40 500毫秒。 </li><li>选择强度基于广泛的试点测试的水平。保持跨越参与者它不变。 注:对于设备üSED这里，常用强度介于50 -最大刺激器输出11,41-44的70％。 </li><li>选择一个试验间隔。 5秒27,45 -对于兼具实用和安全的原因，由最低3分开的刺激试验。 </li></ol> 2执行主管注册<ol><li>获取高分辨率，T1加权解剖磁共振成像（MRI）扫描在一个单独的会话在TMS之前，每个参与者。将在步骤2.3中使用的图像中包含的基准点。 </li><li>加载扫描到无框立体定向系统TMS的会议之前，让每个参与者的刺激部位的准确定位。马克在头部的刺激部位在实验开始时或在整个实验持续监控。 </li><li>纪念参与者的形象在四个基准点。通常，这些包括鼻尖，鼻桥，以及不CH每个耳朵的耳屏上。 </li><li>提供有关TMS参与者的信息，以便他们作出知情同意参加试验。 </li><li>请参与者完成已批准的机构审查委员会TMS的屏幕保护形式。 注意:长期矛盾，TMS包括癫痫的个人史或家族史，神经或精神问题的临床病史，或植入式医疗设备，如心脏起搏器或植入人工耳蜗。不遵守TMS的安全要求可能会引起晕厥和癫痫发作。 </li><li>广场上的参与者的头部的主题跟踪;它会测量基准点时，作为参考。触摸每一个基准点关于这个问题的头自带的立体定向系统的指针，并保存在计算机上的相应坐标。校准对象的头部与MRI图像。入住登记和重复的质量这个过程，如果必要的。 </li><li>请参与者的刺激时戴上耳塞，以减轻线圈放电的声音，避免损坏参与者的听证会46。 </li><li>根据第1节中所做的选择设置TMS机。 </li><li>测试，以确保参加者熟悉它的感觉和容忍以及之前介绍的参与者刺激。首先证明在研究人员的手臂的刺激，然后在参与者的臂来适应环境的人的感觉。 注意:这是为参与者谁遇到TMS的第一次尤为重要。 </li><li>表明在每个测试位点的感觉刺激协议可以是不同的在不同的位置。放置在线圈上的第一个位点所确定的无框立体定向系统，使得线圈相切头皮和最大磁通的线相交的圣imulated网站。 注:刺激有时会影响面部神经和肌肉，并可能导致不适，以便测试参与者是否容忍它做好是很重要的。 </li></ol> 3，执行的职能定位<ol><li>通过它定制到每个参与者优化的刺激部位。马克参与者的结构图像上感兴趣的脑区域内的几个潜在的刺激部位。彼此定位目标10mm以上给出的TMS 47的使用网格或解剖标记（ 图1）的空间分辨率。 </li><li>选择一个本地化的任务，水龙头到感兴趣的认知功能，并有一个可衡量的行为（ 例如 ，反应时间，精确度，眼球运动）。测试的可能地点时，重复的任务多次，并创建不同版本的任务，以避免刺激不断的重复。 </li><li>允许参与者练习任务，而不刺激直到他们舒服。然后引入第二次练习赛与TMS随机（或伪随机）提交了一份关于试验的50％，使参与者习惯了而不必分心刺激执行任务。 </li><li>选择一个测试网站，并运行航向任务的一个版本。随后马上检查结果，看看是否刺激影响性能。 注:在许多情况下，刺激的"不正确"的网站实际上将有利于因跨感官便利2，在这种情况下，相对于无刺激反应，由于听力的点击和感觉刺激头皮的感觉。此外，刺激（ 即超过100毫秒）的大影响往往是伪迹，需要重新测试。如果他们复制和特定于某个特别的测试网站，那么他们可能是真正的效果。一定要选择一个强大的度量TMS的效果有信心在localiz通报BULLETIN。 </li><li>如果发现没有效果，选择一个新的测试网站，并重复，否则再次测试同一个网站，以确定它是否复制。测试多个站点背到后端在同一会话中，以确保他们不会都产生影响，因为这将表明非特异性TMS的效果。制衡的网站跨激发参与者的顺序。 </li></ol>四，主要任务<ol><li>本地化后在同一会话中，使用了本地化的功能目标站点运行的主要实验。 注:这将涉及不同的任务，以一个本地化使用，但一个股份中拥有权益的关键过程。例如，韵判断任务可用于定位的区域，以处理的字的声音，而一个同音判断任务可能被用于在主试验敏感。在这个例子中，两个任务需要的书面文字音韵处理虽然具体的任务要求，都能够激活李差异。 </li><li>包括足够的控制条件，以排除TMS的非特异性作用。 </li><li>测试相同的位点上的控制任务不包括感兴趣的过程，以证明官能特异性的处理。 </li><li>测试的主要任务不同的站点来演示的效果解剖特异性。 </li><li>包括附加的控制条件，如假刺激，控制刺激，或多个时间窗口。 </li><li>使用本地化过程中所使用的相同的TMS参数（ 如强度，频率和刺激的持续时间）进行传统的"虚拟病变"的实验。对于计时TMS实验中，使用相同的强度，但更换由一个单一的48或双脉冲49在不同的发病延迟交付本地化过程中使用的脉冲串。 </li></ol>

作者宣称，他们有没有竞争的财务权益。

本文介绍了一个协议，用于评估的因果和脑区的时间参与网上使用TMS的认知过程。这个讨论突出了先为创造一个成功的TMS方案的关键步骤，然后需要设计的TMS实验时，需要考虑的限制。 因为TMS协议有大量的自由参数，保证了最佳刺激参数是在准备TMS实验的关键步骤。通常情况下，这是通过大量的试验测试，以确定刺激频率，持续时间，强度，试验间隔，并需要产生强大的效果线圈的方向来实现。要建立一个有效的"虚拟病变"的频率必须诱使一个强大的效果，覆盖了足够大的时间窗口，包括感兴趣的认知过程。其结果是，频率和持续时间不同研究有所不同。同样，＆＃8220;右"的刺激强度是1，保证了磁场影响神经处理在目标脑区域和这里的主要因素是从线圈到刺激位点51的距离。许多研究确定必要的刺激强度刺激初级运动皮层的手区域时，产生运动反应，并以此来标准化强度跨参与者52,53-55。这一措施，然而，这不是对非运动区域42,51,56的最优强度的可靠指标。另一个选项是使用相同的强度为所有参与者。与一系列刺激强度试验后，所选择的强度应在所有试验对象有效。此外，线圈的方向是需要考虑的重要参数。在特定线圈取向影响感应电场的刺激的神经元群中的分布，因而可影响BEHAVIOR。一般情况下，发布的协议可以提供一个试点过程中反复修改，以适应特定实验的起点。然而，通常这个试点信息从最终的手稿，其中有隐藏的协议设计过程中的一些关键方面的不幸影响省略。 选择一个本地化过程也是至关重要的，以确保刺激施用到最佳站点。虽然许多研究都使用针对整个个体参与者57,58单一地点解剖学为基础的方法，定制的刺激部位为每个主体成功的局部刺激位点在行为结果产生一个更有效的方法31方差主体之间分别减少了。在这里，我们提出了一个TMS为基础的功能定位程序，提供优于功能磁共振成像为基础的定位。具体地讲，它避免了不同的空间偏差的问题是之间的fMRI（ 即 ，引流静脉59）和TMS（ 即 ，磁场6,60内的轴突的定向）可能导致被定位于不同的位置相同的神经响应。此外，它是众所周知，在fMRI的激活的"峰"的具体位置可以变化很大，这使它们次优的TMS目标55,61。即使如此，各种不同的定位的程序是证明有效的，所以具体的选择是不太重要的，以确保无论采用哪种方法提供了可靠的，可重现的效果。 虽然实验数据这里介绍用的反应时间作为因措施，有许多可用的其他选项。例如，一些研究使用的准确性，而不是9,12,62。在这些情况下，TMS不正常的表现已经低于上限水平，从而诱发刺激的干扰是体现在准确度分数。其他研究也测量刺激对眼球运动63,64的影响。大多数认知神经科学实验与TMS，但是，使用的反应时间作为其依赖的措施13,48,65,66。通常情况下，效果是几十毫秒，大约一个在反应时间67 10％的变化的顺序。任何依赖的测度用于应健壮和一致，使相对较小的变化可以很容易地观察到。 像任何实验技术，TMS有需要时，选择这种方法要考虑的重要限制。最常见的是:i）TMS的空间分辨率，ⅱ）的非特异性作用与刺激有关ⅲ）安全方面的方法及。首先，TMS有刺激作用的一个有限的深度，因为磁场的强度降低了进一步远离它是从线圈。因此，它是在刺激大脑区域附近的头皮最有效的（〜2 - 3公分）68,69 </sup&gt;和无效刺激脑深部结构。作为结果，只有区域直接访问TMS限于皮质地幔，虽然不同形状的线圈被开发以达到更深的区域，例如基底神经节69。 TMS也有大约0.5的空间分辨率- 1厘米47,70-72。因此，该方法不能被用于研究的官能度从细粒度的空间结构，例如皮质列。 TMS的第二个限制是，引入的刺激感官的并发副作用迅速变化的磁场中的结果。最值得注意的是，每一个磁脉冲是伴随着听觉点击和敲击感。因此，TMS可能不适合某些听觉或体感实验，而这些副作用可能与任务绩效干扰。注意，但是，该在线TMS已经成功地用于一些听觉实验73,74 </s向上&gt;，因此是可行的，在至少一些任务。另一个考虑是，感官效果的强度跨头位置不同。例如，刺激被给予的位置靠近耳朵上会比声音更​​响亮地点较远。同样在头部腹面多地点产生比背侧区75,76更大的肌肉收缩。由于这些网站的差异可诱发实验性的困惑，为使用控制网站具有类似的副作用到主站点，如对侧同系物77或包括控制条件/任务不进军感兴趣24,62的过程中是很重要的，73,78,79。 最后，安全性方面的考虑必须始终在设计TMS实验时，因为它可以潜在地诱发晕厥和癫痫发作27考虑。为了尽量减少这种风险，为刺激强度，频率，持续时间和国际公认的准则EXISTS，以及用于脉冲和试验间的间隔27,28的总数。协议留在这些准则被认为是安全的神经正常的人参加。然而，值得注意的是，这些都是尚未完整，往往新颖的TMS协议介绍，也证明安全的。一般情况下，有证据表明，当发布需要遵循的准则，TMS是一个安全的程序，没有危险的副作用。这些限制的后果之一，然而，就是行为的协议往往需要调整他们可以与TMS在使用之前。这有几方面的设计，包括实验的长度，试验次数，条件和刺激位点，可以进行测试数的影响。其中的一些限制可能通过把实验为单独的会话，如测试在不同的日子不同的刺激就能解决这个问题。在这些情况下，重要的是确保定位是很重要的和现场的测试都在同一会话内完成。这样便可通过最大化为目标的，大大减少了实验的方差。在决定是否使用一个或多个测试环节，最根本的限制是参与者的安全 - 特别刺激，是安全在单个会话的数量。总的刺激涉及熟悉，实践中，定位（如果使用TMS），和测试，可能在多个位点，并极大程度上取决于每种条件试验次数。凡这一数字超过在单个会话的指引，有必要打破实验分为多个阶段，进行至少24小时开。没有关于必要为​​TMS实验试验中的最小数目的硬和快速的规则，但像任何实验中，这些可以使用基于效果的大小，方差，α-（通常为0.05）的标准功率计算来计算与期望的灵敏度。常合理的估计规模效应和方差可作为广泛的试点做了优化实验方案的结果。 综上所述，TMS已经成为具有广泛应用认知神经科学的一个重要工具。本文提供了一个行为的任务相结合的调查无论是在"虚拟病变"的模式，也是一个计时工具，探索区域特有的神经信息处理的时间动态因果脑 - 行为关系的基本协议，用于在线TMS。

经颅磁刺激（TMS）是用于脑刺激一种安全，非侵入性的工具。它使用了一个导电线圈内的快速变化的电流，以产生一个强，但相对焦距，磁场。当应用到头皮中，磁场诱导的电活动中的底层的脑组织，暂时中断本地皮层的信息处理。这种瞬态干扰有效地创建了一个短暂的"虚拟病变"1,2。这种技术提供了绘制因果脑与行为的推论和网上调查的神经信息处理的时间动态在健康成人和神经病患者的非侵入性的方法。 通过与区域特有的皮质处理选择性地干扰，TMS可用于绘制脑区域和特定行为3,4之间的因果联系。也就是说，如果显著刺激皮质区影响相对于适当的控制条件下工作的性能，这表明刺激面积是必要的，通常执行的任务。这样的因果推论是TMS过影像学方法，如功能性磁共振成像（fMRI）或正电子发射断层扫描（PET）的主要优势之一。不同于测量神经活动和行为，其相关神经影像技术，TMS提供了机会，扰乱神经信息处理和衡量其对行为的影响。在这个意义上，它更像是在患者的脑损伤，除了TMS为无创和效果是暂时的，可逆的传统病变赤字分析。 TMS也有与损伤研究的几个优点。例如，刺激的影响通常比天然存在的病变，这往往是大的和相差很大横跨患者更精确的空间。此外，与会者可以作为自己的对照，therebŸ避免患者和对照组之间在发病前的能力电位差的问题。最后，没有足够的时间用于功能重组要发生的TMS期间，这意味着恢复过程是不可能混淆的结果5。换句话说，TMS提供了一个功能强大的工具，用于研究因果脑与行为的关系，补充等功能神经影像学相关技术。 TMS也可用于通过使用刺激的非常短的脉冲串和不同刺激6的发病，调查神经信息处理的时间过程。通常，这涉及任一输送到区域在一个试验中不同时间点的一个单或双脉冲TMS。因为一个单独的TMS脉冲的作用立即发生，持续介于5和40毫秒7-10，这使得研究者能够映射区域的神经元活动的时间动态的，包括其ONSET，持续时间和偏移11,12。这个中断的时间限制了该技术的时间分辨率为毫秒的10秒，震级粗糙的大约比脑电图（EEG）和脑磁图（MEG）的订单。在另一方面，在计时TMS研究中观察到的时序往往会匹配那些从微创神经生理学的录音比EEG和MEG 9,13更好。据推测，这是因为EEG和MEG测量大型神经元同步的滞后活动14最早发病。此外，像功能磁共振成像和PET，EEG和MEG是全脑活动的相关措施，而计时TMS不仅可以提供有关区域时空动态也左右着区域的必要性对于一个给定行为的重要信息。 虽然TMS最初是为调查该电机系统15的生理，它很快就被采纳为cogniti一 ​​个有价值的工具已经神经科学。它的一个最早的用途作为一个"虚拟病变"技术是通过刺激左下额叶皮层16-18诱导讲话逮捕。结果证实布洛卡区的语音生产的重要性，并提出了一个潜在的替代和田测试，以确定神经外科干预16,19以后的语言优势。现在，TMS是用在认知神经科学的几乎所有领域，包括注意力20，存储器21，视觉处理22，行动规划23，决策24，和语言处理25。通常TMS诱发或增加的误差率或更慢的反应时间（RT），这两者都取为脑和行为3,4之间的因果关系的指标。一些研究使用TMS同时在其虚拟病变模式，并作为计时工具。例如，投手和他的同事11首先表明，重复性TMS（rTMS的）传递到枕骨的脸部区域打乱了准确的面部识别，然后用来计时的TMS来确定，这种影响只存在时TMS交付在60和100毫秒，这表明这个特定的大脑区域处理面部部分信息在早期舞台人脸识别。在所有这里提到的实施例中，TMS是施用"在线"，也就是在工作性能，使TMS的影响是直接的和短暂的（ 即 ，效果持续，只要刺激的持续时间）。这与"离线"TMS涉及或长低频刺激21的运行或图案刺激26短时间开始任务之前。在离线TMS的影响最后远远超出了TMS应用程序本身的持续时间。本文只关注了"上线"的方法。 在准备任何TMS E中的初始步骤xperiment包括确定一个刺激方案和选择定位方法。刺激参数包括强度，频率和TMS的持续时间和通过国际确定安全要求27,28被约束。每个TMS实验还需要用于定位一个合适的定位过程，准确地定向的线圈在刺激部位。定位可以基于标准的空间坐标29或10 - 20的定位系统30，但通常被定制为每个单个参与者31。对于后者，也有根据每个人的解剖32多种选项，其中包括针对刺激，使用fMRI 33或功能使用TMS 34定位功能定位。这里介绍的协议主张与TMS的功能定位作为一般协议上线TMS实验的一部分。然后一个说明性的例子给出的TMS如何使用调查左缘上回（SMG）的在读语音处理功能的贡献。

<table><tbody><tr><td>Magstim Rapid2 stimulator</td><td>Magstim, Carmarthenshire, UK</td><td></td><td></td></tr><tr><td>70 mm diameter figure-of-eight coil</td><td></td><td></td><td></td></tr><tr><td>Brainsight frameless stereotaxy system</td><td>RogueResearch, Montreal, Canada</td><td></td><td></td></tr><tr><td>Polaris Vicra infrared camera</td><td>Northern Digital, Waterloo, ON, Canada</td><td></td><td></td></tr></tbody></table>

transcranial magnetic stimulation for investigating causal brain-behavioral relationships and their time course

经颅磁刺激（TMS）是一种使用强大的电磁铁，以暂时中断信息处理的脑区，产生一个短命的一种安全，无创性脑刺激术"虚拟病变。"刺激与任务绩效干扰指示该受影响的脑区是必要的，通常执行的任务。换句话说，不像神经成像方法，如功能性磁共振成像（fMRI），表明大脑和行为之间的相互关系，TMS可以用来证明因果脑行为的关系。此外，通过改变虚拟病变的持续时间和发病，TMS也揭示了在正常处理的时间过程。因此，TMS已经成为认知神经科学的一个重要工具。该技术与损伤赤字研究的优点包括的破坏效果更好时空精度，利用参与者作为自己的合作能力ntrol科目，以及参与者的可访问性。的限制，包括并发的听觉和体感的刺激，可能会影响工作性能，有限的访问结构多于从头皮表面几厘米，而这需要为了在实验过程中的工作进行优化的自由参数的比较大的空间。 ，要适当的控制条件，仔细考虑实验设计有助于解决这些问题。本文说明这些问题与调查左缘上回（SMG）的阅读空间和时间贡献TMS结果。

图2示出了作为例子2 TMS实验的结果。即，首先调查左SMG是否是因果地参与处理的字的声音，而第二个研究这种介入的时间动态。 图2A显示了第一个实验的代表性结果，其中的rTMS（10赫兹，5个脉冲，55％的最大强度）交付给上海文广在三个任务。音韵任务集中在单词的发音注意力（"你这两句话听起来一样的吗？ 知道鼻 "），而语义任务集中在自己的意思（"你这两个词的意思是一回事吗？ 理念-概念 "）。第三个控制任务提出了双辅音字母串，并询问他们是否是相同的（"wsrft-wsrft"）。每个任务都包括了100次试验。结果表明，TMS保留时间相对显著增加至不stimulation以平均37毫秒的语音任务。相比之下，上海文广刺激对在语义或字形控制任务的反应时没有显著作用。换句话说，左竞彩"虚拟病变"选择性干预处理的话的声音，说明SMG在处理的书面文字44音韵方面的必要性。 图2B显示了计时实验探究语音处理的时间过程内SMG的代表性结果。在这里，双脉冲TMS 100试验分为五个相等的块，每块测试不同的时间窗相同的语音任务中被交付在五个不同的时间窗刺激后发病。相较于基线条件（40/80毫秒），在反应时显著增加时TMS交付一百二十○分之八十○，120/160和二百分之一百六毫秒的刺激后发病观察。这些结果证明SMG是从事Windo教育署在80和200毫秒刺激后发病，之间的语音处理表明早期和持续的参与语音加工44。 <img alt="图1" src="/files/ftp_upload/51735/51735fig1highres.jpg" /> 图1。标记潜在的刺激位点的两种常用方法。（A）第一种方法是将标记的格子在手运动区和测试每个直到TMS产生预期的效果。这种做法是很常见的识别电机"热点" -也就是在那里产生刺激最强，最可靠的肌肉收缩的地方（B）第二种方法通过将一组标记内定义良好的应用解剖额外约束。大脑区域。在这个例子中，三个标记的位置被限制为冲锋枪的前部区域。第一个是定位●优异的​​外侧裂的后升支的终止;第二个是前SMG腹结束;而第三个是约半途其他两个位点之间。刺激标记显示使用无框立体定向系统中的个人MRI扫描的矢状平面。在左下角的黑色比例尺表示1厘米的距离。 <img alt="图2" src="/files/ftp_upload/51735/51735fig2highres.jpg" /> 图2。从刺激的开始反应时间（RT）。 （一）noTMS（光棒）和TMS（暗杠）在三个不同的语言任务的条件。（b）五位刺激的计时条件的音韵任务。在这里介绍的例子，双脉冲交付在任40/80毫秒，80/120毫秒，120 / 160msec的，二百分之一百六毫秒，200/24​​0毫秒刺激后发病。钍Ë第一时间窗口，40/80毫秒，被用来作为基准控制条件，因为没有预期的视觉信息在SMG，可以快速到达。误差棒代表平均值的标准误差调整，以正确反映受试者内方差50。第一个实验中包含的12名学员和32名第二个数据。 * P &lt;0.05。

Watch this Scientific Journal Video about Transcranial Magnetic Stimulation for Investigating Causal Brain-behavioral Relationships and their Time Course at JoVE.com

Transcranial Magnetic Stimulation for Investigating Causal Brain-behavioral Relationships and their Time Course

经颅磁刺激（TMS）是用于非侵入性地破坏神经信息处理及测量其上的行为效果的技术。当TMS干扰任务时，它表明刺激大脑区域是必要的正常工作性能，允许一个系统有关的大脑区域，以认知功能。

经颅磁刺激对调查因果脑 - 行为关系及其时间进程

Transcranial magnetic stimulation (TMS) is a safe, non-invasive brain stimulation technique that uses a strong electromagnet in order to temporarily ...

transcranial-magnetic-stimulation-for-investigating-causal-brain

Universidad San Sebastian

Research

JoVE Journal

Behavior

42.9K 次观看.  University College London. 经颅磁刺激（TMS）是用于非侵入性地破坏神经信息处理及测量其上的行为效果的技术。当TMS干扰任务时，它表明刺激大脑区域是必要的正常工作性能，允许一个系统有关的大脑区域，以认知功能。 

视频: Transcranial Magnetic Stimulation for Investigating Causal Brain-behavioral Relationships and their Time Course

Transcranial Direct Current Stimulation and Simultaneous  Functional Magnetic Resonance Imaging

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp to manipulate cortical excitability and, consequently, behavior and brain function. In the last decade, numerous studies have addressed short-term and long-term effects of tDCS on different measures of behavioral performance during motor and cognitive tasks, both in healthy individuals and in a number of different patient populations. So far, however, little is known about the neural underpinnings of tDCS-action in humans with regard to large-scale brain networks. This issue can be addressed by combining tDCS with functional brain imaging techniques like functional magnetic resonance imaging (fMRI) or electroencephalography (EEG).
In particular, fMRI is the most widely used brain imaging technique to investigate the neural mechanisms underlying cognition and motor functions. Application of tDCS during fMRI allows analysis of the neural mechanisms underlying behavioral tDCS effects with high spatial resolution across the entire brain. Recent studies using this technique identified stimulation induced changes in task-related functional brain activity at the stimulation site&#160;and also in more distant brain regions, which were associated with behavioral improvement. In addition, tDCS administered during resting-state fMRI allowed identification of widespread changes in whole brain functional connectivity.
Future studies using this combined protocol should yield new insights into the mechanisms of tDCS action in health and disease and new options for more targeted application of tDCS in research and clinical settings. The present manuscript describes this novel technique in a step-by-step fashion, with a focus on technical aspects of tDCS administered during fMRI.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique. It has successfully been used in basic research and clinical settings to modulate brain function in humans. This article describes the implementation of tDCS and simultaneous functional magnetic resonance imaging (fMRI), to investigate the neural basis of tDCS effects.

经颅直流电刺激和同步功能磁共振成像

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp ...

科研

行为学

Simultaneous Transcranial Alternating Current Stimulation and Functional Magnetic Resonance Imaging

Transcranial alternating current stimulation (tACS) is a promising tool for noninvasive investigation of brain oscillations. TACS employs frequency-specific stimulation of the human brain through current applied to the scalp with surface electrodes. Most current knowledge of the technique is based on behavioral studies; thus, combining the method with brain imaging holds potential to better understand the mechanisms of tACS. Because of electrical and susceptibility artifacts, combining tACS with brain imaging can be challenging, however, one brain imaging technique that is well suited to be applied simultaneously with tACS is functional magnetic resonance imaging (fMRI). In our lab, we have successfully combined tACS with simultaneous fMRI measurements to show that tACS effects are state, current, and frequency dependent, and that modulation of brain activity is not limited to the area directly below the electrodes. This article describes a safe and reliable setup for applying tACS simultaneously with visual task fMRI studies, which can lend to understanding oscillatory brain function as well as the effects of tACS on the brain.

Transcranial alternating current stimulation (tACS) is a promising tool for noninvasive investigation of brain oscillations, though its effects are not completely understood. This article describes a safe and reliable setup for applying tACS simultaneously with functional magnetic resonance imaging, which can increase understanding oscillatory brain function and effects of tACS.

同时经颅交替电流刺激和功能磁共振成像

Transcranial alternating current stimulation (tACS) is a promising tool for noninvasive investigation of brain oscillations. TACS employs ...

Brain State-dependent Brain Stimulation with Real-time Electroencephalography-Triggered Transcranial Magnetic Stimulation

The effect of a stimulus to the brain depends not only on the parameters of the stimulus but also on the dynamics of brain activity at the time of the stimulation. The combination of electroencephalography (EEG) and transcranial magnetic stimulation (TMS) in a real-time brain state-dependent stimulation system allows the study of relations of dynamics of brain activity, cortical excitability, and plasticity induction. Here, we demonstrate a newly developed method to synchronize the timing of brain stimulation with the phase of ongoing EEG oscillations using a real-time data analysis system. This real-time EEG-triggered TMS of the human motor cortex, when TMS is synchronized with the surface EEG negative peak of the sensorimotor &#181;-alpha (8-14 Hz) rhythm, has shown differential corticospinal excitability and plasticity effects. The utilization of this method suggests that real-time information about the instantaneous brain state can be used for efficacious plasticity induction. Additionally, this approach enables personalized EEG-synchronized brain stimulation which may lead to the development of more effective therapeutic brain stimulation protocols.

This paper describes real-time electroencephalography-triggered transcranial magnetic stimulation to study and modulate human brain networks.

脑状态依赖性脑刺激与实时脑脑图触发颅内磁刺激

The effect of a stimulus to the brain depends not only on the parameters of the stimulus but also on the dynamics of brain activity at the time of the ...

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological effects. Specifically, by creating a transient interference with the normal activity of a target region and measuring changes in an electrophysiological signal, we can establish a causal link between the stimulated brain area or network and the electrophysiological signal that we record. If target brain areas are functionally defined with prior fMRI scan, TMS could be used to link the fMRI activations with evoked potentials recorded. However, conducting such experiments presents significant technical challenges given the high amplitude artifacts introduced into the EEG signal by the magnetic pulse, and the difficulty to successfully target areas that were functionally defined by fMRI. Here we describe a methodology for combining these three common tools: TMS, EEG, and fMRI. We explain how to guide the stimulator&#39;s coil to the desired target area using anatomical or functional MRI data, how to record EEG during concurrent TMS, how to design an ERP study suitable for EEG-TMS combination and how to extract reliable ERP from the recorded data. We will provide representative results from a previously published study, in which fMRI-guided TMS was used concurrently with EEG to show that the face-selective N1 and the body-selective N1 component of the ERP are associated with distinct neural networks in extrastriate cortex. This method allows us to combine the high spatial resolution of fMRI with the high temporal resolution of TMS and EEG and therefore obtain a comprehensive understanding of the neural basis of various cognitive processes.

This paper describes a method for collecting and analyzing electroencephalography (EEG) data during concurrent transcranial magnetic stimulation (TMS) guided by activations revealed with functional magnetic resonance imaging (fMRI). A method for TMS artifact removal and extraction of event related potentials is described as well as considerations in paradigm design and experimental setup.

提取脑电数据视觉诱发电位记录在功能磁共振成像引导下经颅磁刺激

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological ...

神经科学

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of neurological and psychiatric disorders such as stroke and depression. Yet, the mechanisms underlying its ability to modulate brain excitability to improve clinical symptoms remains poorly understood 33. To help improve this understanding, proton magnetic resonance spectroscopy (1H-MRS) can be used as it allows the in vivo quantification of brain metabolites such as &#947;-aminobutyric acid (GABA) and glutamate in a region-specific manner 41. In fact, a recent study demonstrated that 1H-MRS is indeed a powerful means to better understand the effects of tDCS on neurotransmitter concentration 34. This article aims to describe the complete protocol for combining tDCS (NeuroConn MR compatible stimulator) with 1H-MRS at 3 T using a MEGA-PRESS sequence. We will describe the impact of a protocol that has shown great promise for the treatment of motor dysfunctions after stroke, which consists of bilateral stimulation of primary motor cortices 27,30,31. Methodological factors to consider and possible modifications to the protocol are also discussed.

This article aims to describe a basic protocol for combining transcranial direct current stimulation (tDCS) with proton magnetic resonance spectroscopy (1H-MRS) measurements to investigate the effects of bilateral stimulation on primary motor cortex metabolism.

磁共振波谱的用途，用于对初级运动皮层新陈代谢双半球经颅电刺激效果的测量工具一

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of ...

A Multimodal Imaging- and Stimulation-based Method of Evaluating Connectivity-related Brain Excitability in Patients with Epilepsy

Resting-state functional connectivity MRI (rs-fcMRI) is a technique that identifies connectivity between different brain regions based on correlations over time in the blood-oxygenation level dependent signal. rs-fcMRI has been applied extensively to identify abnormalities in brain connectivity in different neurologic and psychiatric diseases. However, the relationship among rs-fcMRI connectivity abnormalities, brain electrophysiology and disease state is unknown, in part because the causal significance of alterations in functional connectivity in disease pathophysiology has not been established. Transcranial Magnetic Stimulation (TMS) is a technique that uses electromagnetic induction to noninvasively produce focal changes in cortical activity. When combined with electroencephalography (EEG), TMS can be used to assess the brain's response to external perturbations. Here we provide a protocol for combining rs-fcMRI, TMS and EEG to assess the physiologic significance of alterations in functional connectivity in patients with neuropsychiatric disease. We provide representative results from a previously published study in which rs-fcMRI was used to identify regions with abnormal connectivity in patients with epilepsy due to a malformation of cortical development, periventricular nodular heterotopia (PNH). Stimulation in patients with epilepsy resulted in abnormal TMS-evoked EEG activity relative to stimulation of the same sites in matched healthy control patients, with an abnormal increase in the late component of the TMS-evoked potential, consistent with cortical hyperexcitability. This abnormality was specific to regions with abnormal resting-state functional connectivity. Electrical source analysis in a subject with previously recorded seizures demonstrated that the origin of the abnormal TMS-evoked activity co-localized with the seizure-onset zone, suggesting the presence of an epileptogenic circuit. These results demonstrate how rs-fcMRI, TMS and EEG can be utilized together to identify and understand the physiological significance of abnormal brain connectivity in human diseases.

Resting-state functional-connectivity MRI has identified abnormalities in patients with a wide range of neuropsychiatric disorders, including epilepsy due to malformations of cortical development. Transcranial Magnetic Stimulation in combination with EEG can demonstrate that patients with epilepsy have cortical hyperexcitability in regions with abnormal connectivity.

评价中的连接有关的大脑兴奋患者癫痫多式联运Imaging-和激励为基础的方法

Resting-state functional connectivity MRI (rs-fcMRI) is a technique that identifies connectivity between different brain regions based on correlations ...

医学

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.

Transcranial Alternating Current Stimulation (tACS) allows the modulation of cortical excitability in a frequency-specific fashion. Here we show a unique approach which combines online tACS with single pulse Transcranial Magnetic Stimulation (TMS) in order to "probe" cortical excitability by means of Motor Evoked Potentials.

经颅磁刺激在线联合方法对经颅交流电刺激对原发性运动皮层的影响

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific ...

Combined Transcranial Magnetic Stimulation and Electroencephalography of the Dorsolateral Prefrontal Cortex

Transcranial magnetic stimulation (TMS) is a non-invasive method that produces neural excitation in the cortex by means of brief, time-varying magnetic field pulses. The initiation of cortical activation or its modulation depends on the background activation of the neurons of the cortical region activated, the characteristics of the coil, its position and its orientation with respect to the head. TMS combined with simultaneous electrocephalography (EEG) and neuronavigation (nTMS-EEG) allows for the assessment of cortico-cortical excitability and connectivity in almost all cortical areas in a reproducible manner. This advance makes nTMS-EEG a powerful tool that can accurately assess brain dynamics and neurophysiology in test-retest paradigms that are required for clinical trials. Limitations of this method include artifacts that cover the initial brain reactivity to stimulation. Thus, the process of removing artifacts may also extract valuable information. Moreover, the optimal parameters for dorsolateral prefrontal (DLPFC) stimulation are not fully known and current protocols utilize variations from the motor cortex (M1) stimulation paradigms. However, evolving nTMS-EEG designs hope to address these issues. The protocol presented here introduces some standard practices for assessing neurophysiological functioning from stimulation to the DLPFC that can be applied in patients with treatment resistant psychiatric disorders that receive treatment such as transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), magnetic seizure therapy (MST) or electroconvulsive therapy (ECT).

The protocol presented here is for TMS-EEG studies utilizing intracortical excitability test-retest design paradigms. The intent of the protocol is to produce reliable and reproducible cortical excitability measures for assessing neurophysiological functioning related to therapeutic interventions in the treatment of neuropsychiatric diseases such as major depression.

侧前额叶皮质联合经颅磁刺激与脑电图的研究

Transcranial magnetic stimulation (TMS) is a non-invasive method that produces neural excitation in the cortex by means of brief, time-varying magnetic ...

Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation

Understanding interactions between brain areas is important for the study of goal-directed behavior. Functional neuroimaging of brain connectivity has provided important insights into fundamental processes of the brain like cognition, learning, and motor control. However, this approach cannot provide causal evidence for the involvement of brain areas of interest. Transcranial magnetic stimulation (TMS) is a powerful, noninvasive tool for studying the human brain that can overcome this limitation by transiently modifying brain activity. Here, we highlight recent advances using a paired-pulse, dual-site TMS method with two coils that causally probes cortico-cortical interactions in the human motor system during different task contexts. Additionally, we describe a dual-site TMS protocol based on cortical paired associative stimulation (cPAS) that transiently enhances synaptic efficiency in two interconnected brain areas by applying repeated pairs of cortical stimuli with two coils. These methods can provide a better understanding of the mechanisms underlying cognitive-motor function as well as a new perspective on manipulating specific neural pathways in a targeted fashion to modulate brain circuits and improve behavior. This approach may prove to be an effective tool to develop more sophisticated models of brain-behavior relations and improve diagnosis and treatment of many neurological and psychiatric disorders.

This article describes new approaches to measure and strengthen functionally specific neural pathways with transcranial magnetic stimulation. These advanced noninvasive brain stimulation methodologies can provide new opportunities for the understanding of brain-behavior relations and development of new therapies to treat brain disorders.

利用颅内磁刺激测量和操纵人体运动系统中功能特定的神经通路

Understanding interactions between brain areas is important for the study of goal-directed behavior. Functional neuroimaging of brain connectivity has ...

Employing Transcranial Magnetic Stimulation in a Resource Limited Environment to Establish Brain-Behavior Relationships

Neuroimaging is typically perceived as a resource demanding discipline. While this is the case in certain circumstances, institutions with limited resources have historically contributed significantly to the field of neuroscience, including neuroimaging. In the study of self-deception, we have successfully employed single-pulse TMS to determine the brain correlates of abilities including overclaiming and self-enhancement. Even without the use of neuro-navigation, methods provided here lead to successful outcomes. For example, it was discovered that decreases in self-deceptive responding lead to a decrease in affect. These methods provide data that are reliable and valid, and such methods provide research opportunities otherwise unavailable.&#160;Through the use of these methods, the overall knowledge base in the field of neuroscience is expanded, providing research opportunities to students such as those at our institution&#160;(Montclair State University is a Hispanic-Serving Institute) who are often denied such research experiences.

Transcranial Magnetic Stimulation (TMS) and low-frequency TMS (lfTMS) have&#160;been demonstrated to be major contributors to brain literature. Here we highlight the methods for investigating the cortical correlates of self-deception using TMS.