作者没有致谢。

本议定书经当地道德委员会批准, 实验符合赫尔辛基宣言 (1964). 
 1. 道德认同和主题说明 <ol> <li> 在开始测量之前, 请所有参与者了解潜在的风险因素和研究的目的。不要给出注意力焦点的信息, 因为这可能会影响结果。确保在研究设置中应用 TMS 的安全指南 30 被遵循. 
	注: 在应用 TMS 时, 有一些医疗风险因素, 包括植入的颅电极和人工耳蜗, 晕厥或癫痫的个人病史, 癫痫, 脑损害, 药物/药物相互作用, 最近的药物提取, 怀孕,或疾病。TMS 不应该被管理在孩子. </li>
	<li> 在该研究中, 包括健康的参与者 (n = 14), 介于18和35岁之间。排除任何骨科和/或神经/精神疾病的对象。确保所有参与者都是右撇子. </li>
</ol> 2。实验设计和设置 <ol> <li> 将组划分为两个。指示小组的一半在如果指示首先, 跟随 EF 指示在第二个实验性会议 (参见部分4.2.2 为口头指示)。以抵消的顺序指示另一半. 
	注: 该实验由总共四实验室会话组成 (请参见 图 1 ), 它必须至少用72小时来分隔。前两次会议包括测量最大力 (Fmax) 和最大持续食指绑架的专题信托基金 (见步骤 4)。第三和第四届会议由 subTMS 和 ppTMS (参见 图 1 ) 测量任务期间 M1 内抑制电路的活动. </li>
</ol> 3。主题准备 <ol> <li> 在整个实验过程中, 将参与者置于可调节和舒适的座椅中。在参与者前面放置一个监视器 1 m. </li>
	<li> 将左臂放在桌子下面舒适而放松的位置上, 搁在左腿上。如果需要, 调整手臂的位置与枕头。将主体的右臂放在旋位置的 custom-built 夹板中 (参见 图 2 ). 
	注意: 在这里, 夹板是由热塑性塑料制成, 适合所有参与者 (详见 16 )。另外, 夹板被设想限制腕关节的自由度 (参见 图 2B )。唯一的运动允许的是绑架和内收的食指的右手掌关节. </li>
	<li> 将手指关节与 custom-made 设备的旋转轴对齐。一旦找到最佳的位置, 手动记录, 并采取前-后部和译侧位置的夹板, 在 2, 3 和4节中使用可比较的位置. </li>
</ol> 4。会话1和 2: 行为测试 <ol> <li> 最大等距收缩 (请参见 图 1A )。
	<ol> <li> 对齐测和掌接头的旋转轴, 并使用螺钉正确修复测 (请参见 图 2 )。将力传感器放置在允许最大自愿收缩的方式上 (请参见 图 2B ). </li>
		<li> 将肌电信号电缆 (FDI 肌肉)、力传感器和测电缆连接到适当的放大器和/或模拟到数字 (A-D) 转换. </li>
		<li> 让参与者执行3个食指的最大等距劫持, 每次收缩之间有30秒的间隔, 并确定 Fmax. 
		注: Fmax 被确定为从力传感器获得的力信号的最高峰值。向参与者解释最大的收缩是由 0 N 到个体最大值的渐进力的增加。重要的是, 指导参与者对静止力传感器进行等距收缩。参赛者应在掌关节上劫持食指, 用力推, 尽量对抗力传感器。一个3秒的时间跨度应给予每收缩, 并应指示参与者保持最大的力量为 2 s 16 , 25 , 26 。在每次收缩之间, 给参与者一个30秒的休息时间. </li>
		<li> 让主体在力传感器上推动杠杆, 而不给出任何关于注意力焦点的指示. 
		注意: 在2节开始时将完成相同的任务, 以确保 Fmax 和夹板中的位置在会话之间没有改变. </li>
		<li> 在最大收缩后, 卸下力传感器, 使食指在横平面上自由移动 (诱拐/内收). </li>
		<li> 使用计算机上的原始数据计算最大等距劫持 (步骤 4.1.3) 中的 Fmax。确定 30% (Fmax * 0.3; 会话1和 2) 和 10% (Fmax * 0.1; 会话3和 4) 的 Fmax. 
		注: 将 Fmax 视为从力传感器获得的力信号中的最高峰值。在接下来的课程中, 不同的收缩强度 (30% 和 10%) 将从实验的这个阶段获得的 Fmax 计算出来. </li>
		<li> 将一瓶水装入 Fmax 从步骤4.1.6 获得的30% 的量。将 Fmax 的重量附加到设备的绳子上 (请参见 图 2A ). 
		注: 水的体积密度为1公斤/升。因而, 如果 30% Fmax 一个参加者代表0.4 公斤, 调整瓶的重量到等值0.4 公斤. </li>
	</ol> </li> <li> 持续收缩到专题信托基金 (见 图 1A )。
	<ol> <li> 指示参与者有关该任务的信息. 
		注意: 参与者必须通过抵消重量 (参见 图 2 ) 将手指放在目标位置, 从而执行对食指的诱拐。任务必须在任务失败之前执行。任务失败被确定为偏离目标位置大于10度的偏差。偏差由测测量并显示在显示器上 (请参见 图 2B ). </li>
		<li> 随机化会话顺序 (请参见步骤 2.1;EF 或条件)。口头指示参与者在适当的条件 (如果或 EF)。
		<ol> <li> 用于 the EF 条件, 指导如下: #34; 集中在测的位置。尽可能长的保持这个位置。当测的位置发生变化时, 屏幕上红线的粗细会发生变化。更正测的位置, 直到红线再次变薄. #34; 指导参加者和 #34; 控制和集中在测和 #34 的位置; 每年三十年代. </li>
			<li> IF 条件, 指示如下: 和 #34; 专注于你手指的位置。尽可能长的保持这个位置。当手指的位置发生变化时, 屏幕上红线的粗细会发生变化。纠正手指的位置, 直到红线再次变薄. #34; 指示参与者和 #34; 合同和集中在他的手指肌肉和 #34; 每年三十年代. </li>
		</ol> </li> <li> 让参与者通过抵消权重 (请参见 图 2 ) 将手指放在目标位置, 执行对食指的诱拐。让他们执行任务直到任务失败. </li>
		<li> 按 "#34; 记录和 #34; 录制软件上的按钮, 开始记录测信号, 然后等待任务失败。一旦任务失败, 按 #34; 停止录制和 #34; 在录制软件上的按钮停止录制并将测信号保存在计算机上。从骨科夹板中取出参加者和 #39;第一个会话现在结束. </li>
		<li> 尊重最小闭会周期 (72 小时), 重复步骤 4.2. 1-4. 2.4。此外, 在2和3会话和会话3和4之间至少允许72小时的中断. </li>
	</ol> </li> </ol> 5。会话3和 4: 大脑刺激 <ol> <li> 表面肌电信号 (肌) 记录. 
	<ol> <li> 如果需要, 在右侧的外国直接投资肌肉上剃去皮肤上的毛发, 然后用研磨凝胶轻轻擦伤皮肤。用含有80% 乙醇和1% 甘油的溶液消毒研磨部位。允许乙醇蒸发. </li>
		<li> 将银/氯化双极性表面电极放在一根腹部肌腱蒙太奇上, 在 FDI 上有1厘米的极距离。将参考电极放置在 digitus 中的方阵上. </li>
		<li> 将肌电信号电缆 (FDI 肌肉) 和测电缆连接到肌电信号放大器和 A D 转换器. </li>
		<li> 使用 Ag/氯化双极性表面电极记录和测量来自外国直接投资肌肉的脑刺激诱发的肌肉活动和电生理反应. 
		注: 为最终分析 (subTMS 诱导的肌电信号的抑制和峰的幅度), 肌电信号的信号 (来自外国直接投资) 必须调整如下: 放大 x1000, 北海带通滤波10-1000 赫兹, 取样4赫。将所有的肌电信号数据存储在计算机上进行离线分析. </li>
	</ol> </li> <li> 重复步骤3.1 和 3.2. </li>
	<li> 经颅磁刺激 <ol> <li> 用双面胶带固定参与者和 #39 前额上的反光标记. 
		注意: 反射标记允许通过使用神经导航系统在 M1 上不断地将 TMS 传送到目标区域 (请参见 图 2 )。神经导航系统的优势在于, 线圈位置可以相对于空间中的颅骨位置进行记录, 并在整个实验过程中随时进行检查. </li>
		<li> 使用一个95毫米的八线圈的焦点, 附加到 TMS 刺激器, 以提供对对侧运动皮层手区域的刺激. 
		注意: 检查刺激器允许配对脉冲刺激模式 (会话 4)。此外, 诱导电流必须是后向前, 必须以反向模式交付。波形应该是单相的. </li>
		<li> 找到线圈相对于颅骨的最佳位置 (热点), 通过执行一个经典的映射程序来激发外国直接投资肌肉中的运动诱发电位。
		<ol> <li> 首先将线圈的大约0.5 厘米放置在顶点和中线的前面, 线圈手柄指向45和 #176; 朝向对侧的前额. 
			注意: 这将确保诱导电流流与中央沟 31 大致垂直. </li>
			<li> 让参与者使用 TMS 刺激, 从强度低于最大刺激器输出的25% 开始 (美索)。然后, 开始增加刺激强度和移动线圈在译侧和 rostro 锋方向发现热点. </li>
		</ol> </li> <li> 一旦找到热点, 则用神经导航系统记录最佳位置。通过调整刺激器输出的强度来确定主动电机阈值 (aMT)。将 aMT 定义为在五连续试验中超过0.1 毫伏的 FDI 中, 峰振幅的最低强度要求, 以此来激发其在三的 21 . </li>
	</ol> </li> <li> 会话 3: SubTMS 诱导的肌电信号抑制 (见 图 1B )。
	<ol> <li> 通过填充水瓶来准备代表 Fmax 10% 的重量 (请参阅步骤 4.1.7). 
		注: 10% 的 Fmax 是根据 Fmax (最好的3试验) 执行的步骤4.1.3。在阈 TMS 协议中, 只有10% 的 Fmax 必须被选择, 因为它以前已经表明, 疲劳对 subTMS 诱发的肌电信号抑制有影响 32 , 33 。出于同样的原因, subTMS 会议必须在单独的会议上进行。这里使用的水量介于0.3 升 (最小 30% Fmax) 和 1.2 l (最大30% 的 Fmax) 之间. </li>
		<li> 指示参与者有关任务; 运动任务包括在目标位置上按住食指, 通过抵消10% 的轻量 (食指的诱拐; 与1和2会话相同的任务, 但重量更小) </li>
		<li> 当参与者在舒适的位置上保持放松时, 找到最佳的强度以吸引 subTMS-肌电信号抑制, 而不给出任何关于焦点的指示。要做到这一点, 先后减少步骤2% 美索从 aMT 先前确定. </li>
		<li> 当他们仍然坐在宽松和舒适的位置, 让参与者执行两个单独的等距食指绑架在 10% Fmax 和记录的肌电信号的外国直接投资。在这个等距食指绑架, 记录 (通过按下和 #34; 记录和 #34; 在录音软件上的按钮) 20 试验与和20试验没有 TMS, 以随机 interstimulus 间隔时间 (伊图) 范围从0.8 到 1.1 s 16 , 25 , 26 , 33 , 34 在100毫秒时间窗口中. 
		注意: 此间隔可确保参与者不必执行太长时间的马达任务, 从而将疲劳效果降到最低。每个系列后, 检查 subTMS 诱发的肌电信号抑制。
		<ol> <li> 通过将所有负振幅转换为肌电信号的正振幅来应用全校正。平均肌电信号使用 time-normalized 平均值 35 . 
			注意: subTMS 肌电图抑制的开始是指与无 tms 试验之间的差异为至少4毫秒的时间窗口为负值的时刻, 从20到50毫秒后的 tms: 肌电信号 Diff = 肌电信号 无 -肌电信号 与.</li>
		</ol> </li> <li> 重复步骤5.4.3 直到找到最佳的激发强度, 由最大的肌电信号抑制表示. 
		注意: 最佳强度在 aMT 16 的大约80% 处找到. </li>
		<li> 给参与者足够的纪律 (请参见步骤 4.2.2) 关于条件 (如果或 EF)。在每个系列 (步骤 4.2.2) 之前重复上述说明. </li>
		<li> 当他们保持坐在宽松和舒适的位置, 让参加者执行四分开的等量食指绑架 (2 次以每个焦点: EF 和如果) 在 10% Fmax 并且记录外国直接投资的肌电信号。
		<ol> <li> 在这张等距索引中指上, 记录 (通过按下和 #34; 记录和 #34; 在录制软件上的按钮) 40 项试验和40项没有 TMS 的试验, 在平衡为了.对每个条件使用相同的强度 (在点5.4.5 中确定). </li>
		</ol> </li> <li> 在每个系列之间, 允许至少5分钟的中断, 以最小化疲劳引起的任何偏差. </li>
	</ol> </li> <li> 会话 4: ppTMS (见 图 1B ). 
	注: 配对脉冲模式是由 0.8 amt 的条件反射式刺激组成的, 其次是 1.2 amt 的阈控制刺激。
	<ol> <li> 重复步骤 5.1-5.4。简言之, 将肌电信号电极置于外国直接投资肌肉上, 将参与者放在可调节和舒适的座椅上, 并将左臂放在桌子下舒适而轻松的位置 ( 即左腿 )。在 M1 上找到 TMS 的热点. </li>
		<li> 设置刺激器上的强度, ISI 在2.5 毫秒 36 , 以及配对和脉冲 TMS 在 0.25 Hz 之间的间隔. </li>
		<li> 为参与者提供有关条件的充分说明 (请参见步骤 4.2.2) ( 即 IF 或 EF)。在每个系列之前重复上述说明. </li>
		<li> 让参与者执行四单独的等距食指绑架 (2 次, 每个焦点: EF 和 IF) 在10% 的 Fmax 和记录的肌电信号的外国直接投资。在等量收缩期间, 记录 20 TMS 刺激为每个情况 ( 即, 如果和 EF) 以平衡的顺序. 
		注: 一组20刺激必须由10条件的议员 (配对脉冲在 0.8-1.2 amt) 和10控制欧洲议员 (脉冲在 1.2 amt) 组成。对每个条件使用相同的强度 (在步骤5.5.2 中确定). </li>
		<li> 在每个系列之间, 允许至少5分钟的中断, 以尽量减少疲劳引起的任何偏差. </li>
	</ol> </li> </ol> 6。数据处理和分析 <ol> <li> SubTMS. 
	<ol> <li> 如上所述 (步骤 5.1.1.3), 纠正和平均的肌电图进行分析. </li>
		<li> 检测 subTMS-肌电信号抑制的起始 (请参见 图 4 ). 
		注意: 它被定义为当所有试验的平均值和无 tms 的平均值之间的差为4毫秒的时候, 从20-50 毫秒到 tms. </li>
		<li> 要检测 subTMS-肌电图抑制的结束, 定义抑制开始后的时刻 (步骤 6.1.2), 当与无 TMS 的所有试验的平均值之间的差额为至少4毫秒时为正数 (参见 图4a).</li>
		<li> 计算 subTMS 诱发的肌电图如下: 
		肌电信号 Diff = 无 和 #8211; 肌电信号 与 。
		<ol> <li> 计算从起始到终止的累计梯形数值积分, 以量化 subTMS 引起的肌电信号抑制量. </li>
		</ol> </li> </ol> </li> <li> ppTMS. 
	<ol> <li> 使用以下公式将 SICI 的大小表示为与控制管理系统有关的百分比: 100 和 #8211; (条件控制系统管理和 #215; 100)。
		<ol> <li> 将结果用作最终分析的百分比值. </li>
		</ol> </li> <li> 计算峰 (在 mV 中, 在 EF 和 IF 条件下) 的幅度, 并比较最后分析中的两个条件. </li>
	</ol> </li> <li> 肌电信号 
	<ol> <li> 由于背景肌电信号对欧洲议会议员 37 的大小有影响, 所以在 TMS 之前, 通过计算100毫秒窗口中的根均值正方形来确定肌电信号的活动. </li>
	</ol>
	</li>
</ol>

作者没有什么可透露的。

该协议显示了两种可能的方法来研究 M1 内抑制电路的活动使用 TMS。更确切地说, 这两个协议已被用于研究的注意焦点对抑制电路的活动的 M1 内的影响。
所提出的方法的一个限制是, 它并不总是可能导致 subTMS 的肌电图抑制, 而没有在它之前的便利。例如, 在这项研究中, 四受试者必须从最后的分析中移除, 因为它们没有显示出任何一致的 subTMS 诱发的肌电信号抑制。尽管如此, 这种非侵入性的脑刺激方法是公认的测量和量化的活动皮质抑制电路在 M132,34。这项研究的另一个局限是不能排除 subTMS 和 ppTMS 所概述的注意力集中在 M1 上游的大脑区域之间的差异。尽管这两种方法都假设测试皮质 GABA 抑制神经元23,27的响应性, 但 subTMS 的肌电信号抑制量与 SICI 量之间没有相关性.16;需要进一步调查。
另外, 在 TMS 协议期间使用轻的抵抗 (10% Fmax) 是重要的, 在分开的会议 (≥ 72-h 断裂) 进行 subTMS 实验, 并且随机化条件。其主要原因是疲劳会影响 subTMS 的肌电信号抑制的大小32和 SICI54的水平, 这意味着注意的主要影响可能是由疲劳引起的。在一项累人的任务中, 一些周围的, 皮层下的和皮质的机制也可以发挥关键作用的性能。此外, 它是重要的使用一个神经导航系统, 因为 TMS 线圈必须放置在同一地点, 在每次试验。此外, 这个系统允许实验者检查线圈的位置, 在任何时候在整个实验。
本研究的主要发现是, M1 内的皮质抑制可以根据在运动中所采用的注意焦点在同一主题下立即受到影响。由于抑制过程似乎与一般的马达执行质量密切相关, 我们的结果可能会在神经水平上解释 EF 与 IF 的提高效率。可以推测, 在 EF 中增加的抑制水平避免不必要的互动, 并导致更集中的激活, 导致更有效的马达执行。这样, 我们的结果可能成为 "约束行动假说" 的基本机制之一。此外, 该协议是第一个显示如何应用 subTMS 和 ppTMS 对相同的参与者使用重复措施的设计。此外, 尽管有大量研究表明, 采用 EF 相比, 如果在许多设置中促进了运动的性能和学习1, 在不同注意通过语言指令所规定的情况采用16,28,55。

现在人们普遍认为, 采用 EF 与 IF 或中性关注焦点相比, 可以在许多设置1中促进马达性能和学习。例如, 它已经显示, 采用 EF 带来的好处的准确性2,3, 平衡4,5,6, 强制生产7,8, 跳跃性能7,9,10,11, 移动速度12, 耗氧量13,14, 以及疲劳任务15,16。
另一方面, 由于脑激活是所有运动的基础, 对运动的神经控制的几个方面进行了调查。例如, 在 M1 中调节皮质抑制的水平和能力已经被证明对运动功能有很强的影响, 如间协调17、体位控制18和灵巧性19。此外, 较年轻的成年人, 如年长者或儿童 (早产20) 的运动控制能力较差的人群, 通常表现出不太明显的抑制控制。因此, 虽然抑制过程的作用还没有得到很好的理解, 但抑制过程似乎对一般的电机执行质量很重要。
有可能研究皮质抑制线路是使用无创的经颅磁刺激 (TMS)。最常用的刺激协议应用配对脉冲 TMS (ppTMS) 诱导 SICI。该协议使用低于马达阈值的调节刺激, 以降低阈控制刺激响应的振幅, interstimulus 间隔为1-5 毫秒21,22,23,24. 然后, 报告作为控制刺激的百分比, 运动诱发电位 (欧洲议员) 的振幅可以在不同的条件下进行比较, 提供有关皮质抑制活动和 M1 内调制的信息。
另一种用于评估 intractortical 抑制电路活动的刺激协议适用于单个脉冲, 所有的刺激都在电机阈值以下的强度下传递 (即, subTMS)。此协议在正在进行的肌电信号活动中诱导抑制18,25,26。这种 so-called subTMS 诱导的肌电抑制可以比较的数量和持续时间。虽然此协议不是常用的, 但与标准的 SICI 协议相比, 它具有某些优点。这个协议不干扰马达施行, 因为它不导致阈刺激。两种方法都测试皮质γ-丁酸 (GABA) 抑制神经元的响应性,23,27。
尽管使用 EF 相比, 如果在马达性能1上有众所周知的好处, 但基本的神经过程仍然很不清楚。在前 fMRI 研究28中, 实验表明, 当受试者执行手指序列并采用 EF 与 IF 相比, 血氧水平依赖性 (粗体) 激活在 M1、原发性躯体感觉和岛状皮质中增强。由于兴奋性和抑制性活动不能被区分的 fMRI29, 另一项最近的研究,16规定, 增强活动的 M1 与 EF 可能, 事实上, 是由于增强活动的皮质抑制电路。更确切地说, 这项研究表明, 抑制 gaba 神经元的兴奋性可以立即调整的类型, 注意焦点采取在同一人。
本协议的主要目的是展示两种可能的方法来比较认知操作 (即注意指令的焦点) 对皮质抑制电路在 M1 中的活动的直接影响。SubTMS 和 ppTMS 都使用。此外, 通过对最大等长轴的持续收缩的研究, 探讨了注意焦点对运动行为影响的一种可能的方法。

<table><tbody><tr><td>MC3A-100</td><td>Advanced Mechanical Technologies Inc., Watertown, MA, USA</td><td>-</td><td>Force transducer</td></tr><tr><td>BlueSensor P</td><td>Ambu A/S, Bellerup, Denmark</td><td>-</td><td>Ag/AgCl surface electrodes for EMG</td></tr><tr><td>Polaris Spectra</td><td>Northern Digital, Waterloo, ON, Canada</td><td>-</td><td>neuronavigation system, active or passive markers tracker</td></tr><tr><td>Localite TMS Navigator Version 2.0.5</td><td>LOCALITE GmbH, Sankt Augustin, Germany</td><td>-</td><td>navigation system for transcranial magnetic stimulation (TMS)</td></tr><tr><td>MagVenture MagPro X100</td><td>MagVenture A/S, Farum, Denmark</td><td>9016E0711</td><td>Transcranial magnetic stimulator</td></tr><tr><td>MagVenture D-B80</td><td>MagVenture A/S, Farum, Denmark</td><td>9016E0431</td><td>TMS coil (figure of eight)</td></tr><tr><td>Goniometer</td><td>N/A</td><td>-</td><td>Custom-made goniometer</td></tr><tr><td>Othopedic splint</td><td>N/A</td><td>-</td><td>Custom-made splint</td></tr><tr><td>Recording software</td><td>LabView based</td><td>-</td><td>Custom-made script</td></tr></tbody></table>

intracortical inhibition within the primary motor cortex can be modulated by changing the focus of attention

它是公认的一个外在焦点 (EF) 与内部焦点 (如果) 比较注意改善马达学习和表现。研究表明, 在准确性, 平衡, 力量生产, 跳跃性能, 运动速度, 耗氧量, 和疲劳的任务的好处。虽然使用 EF 策略的行为结果是很好的探索, 但底层的神经机制仍然未知。最近的一项 TMS 研究比较了在 EF 和 IF 之间的主要运动皮层 (M1) 的活动。更确切地说, 该研究表明, 在采用 EF 时, 皮质抑制电路的活性得到提高。
在行为层面上, 本协议在第一次背侧骨间 (FDI) 最大收缩时, 测试注意焦点对任务失败时间的影响。另外, 本文还介绍了两种 TMS 协议来评估注意条件对 M1 内皮层抑制回路活动的影响。因此, 本文介绍了如何使用脉冲 tms 在强度低于电机阈值 (subTMS) 和配对脉冲 tms, 诱导近皮质抑制 (SICI) 时, 适用于 M1。由于这些方法被认为反映了 gaba 抑制神经元的反应性, 而不受脊髓反射线路的影响, 它们非常适合于测量 M1 内皮质抑制回路的活动。
结果表明, 通过外部引导注意力可以提高运动性能, 因为参与者能够延长任务失败的时间。此外, 结果还伴随着一个更大的 subTMS 诱导肌电图抑制和 SICI 时, 采用 EF 与 IF。由于 M1 的皮质抑制水平以前被证明对影响运动性能, 增强的抑制与 EF 可能有助于更好的运动效率观察到的行为任务, 表明由一个长期的专题信托基金与孚.

注意焦点对运动性能的影响:
在目前的研究中, 行为测试被用来证明运动任务的可行性, 并确定在应用 EF 时反应积极的对象。根据先前的研究 (参见1以进行审查), 我们的结果显示, 当参与者通过 EF 与 IF (参见图 3) 进行比较时, 使用了一个长期的专题信托基金。因此, 在等距食指的绑架过程中, 运动的效率可以通过 EF 来提高。McNevin 和同事38假设了 "限制性动作假说" 来解释不同注意力焦点对运动性能和运动学习的影响。作者在他们的假说假设: 使用 EF 改善马达表现通过促进更加自动化在运动控制。相比之下, 采用一个 IF 是应该约束的马达系统, 作为一种更有意识的电机控制的使用。尽管如此, 尽管在一般的1中使用 EF 与 IF 在马达性能上的优势相比, 基本的神经过程仍未得到很好的调查。因此, 核心问题仍然是: 确定与 EF 相比, 增强的运动效率是如何从运动皮层的角度来控制的。
皮质抑制和运动能力:
大脑皮层活动是由兴奋性和抑制机制之间的相互作用的大脑运动区24。此外, 这些过程的调制对于马达控制39是必不可少的。例如, 儿童40、41、42和老年人个人43显示皮质 inhibition-in 的水平与健康、年轻的对象形成对比, 从而降低了协调能力。一般而言, 在考虑不同人群时, 皮质抑制过程和运动性能是紧密相关的。另外, 不仅跨年龄组或不同的人口, 而且在年龄组之内, 马达作用似乎由脊髓抑制的过程强烈改变, 例如间协调17或灵巧性19。因此, M1 内的皮质抑制程度似乎影响了一般电机控制的特点。
注意焦点对皮质抑制的测量及影响:
在以前的 fMRI 研究中, Zentgraf 和同事28开始调查与注意力焦点相关的神经关联 (即, EF 与 IF)。结果显示, 在不同的脑区--M1、岛屿和主要的体感皮层--当受试者在 EF 条件下执行键盘手指序列而非 IF 条件时, 会有更大的活化作用。除了在 EF 和如果任务中研究不同科目的限制, 使直接比较不可能, fMRI 技术不能区分兴奋和抑制神经活动29, 因为它使用固有血液组织对比44。因此, 在 M1 中发现的更高的脑激活在这之前的功能磁共振成像研究中显示28可能是由于兴奋或抑制活动的增加。因此, fMRI 仅提供了对整个神经活动29的估计。相比之下, 在功能磁共振成像的补充, TMS 可以提供有关的性质, 增强活动, 无论是由兴奋或抑制活动的结果。其原因是, tms 应用于 M1 的强度低于主动马达阈值抑制运动皮质输出, 因为皮质抑制 gaba 神经元有一个较低的阈值 tms 比兴奋性神经元27,45,46,47,48. 另外, 它表明, TMS 在马达门限之下不导致下降截击并且, 因此, 不激活脊椎结构23,27。在这项研究中, 我们使用两个 TMS 协议来测量 M1 内的皮质抑制。第一个使用了脉冲 subTMS 协议, 这在持续的肌电信号活动中引起抑制。有人提出, 抑制正在进行的活动的快速传导脊髓细胞的结果, subTMS 诱导肌电信号抑制49。
因此, 皮质抑制电路的兴奋性与 subTMS 诱导的肌电信号抑制量之间存在着关系。换句话说, M1 内皮质抑制的增加会导致更多的肌电信号抑制18。尽管 subTMS 协议没有被广泛使用, 但它与使用 suprathresold 刺激的协议相比, 继承了许多优点: 首先, 由于刺激不增加, 而是从下降的脊髓凌空移除活动, 效果可以清楚地被归因于主要马达皮层, 因为他们不受脊椎线路的影响23,27。其次, 随着阈强度的使用, 没有肌肉抽搐诱发刺激, 这可能会扰乱电机的性能。使用这一技术, 我们证明了 subTMS 的肌电图抑制立即增强, 当使用 EF 与 IF (参见图 4的结果和分析)。具体来说, 我们的结果表明, 当采用不同的注意焦点时, M1 内的皮质抑制回路的活动会立即被调制。
另一个更广泛的可能性, 测量 gaba 马达神经元的活动是应用一个 ppTMS 的范例, 在对对侧 M1 短的 interstimulus 间隔。配对脉冲刺激引起的 SICI 振幅下降, 这是所谓的, 并反映了抑制 gaba 神经元的活动21,45,50。
在采用 EF 时, 参与者显示了更多的 SICI (请参见图 5以了解结果和分析).这与 subTMS 的结果是一致的, 并建议 gaba 神经元, 构成皮质抑制电路51, 根据注意焦点的类型在 M1 内进行不同的调制。这将是与以前的研究表明, M1 是敏感的差异注意情况52。此外, 作为一个积极的相关性之间的脑血流量在运动皮层和数量的 SICI 已经揭示了正电子发射断层扫描研究53, 我们的结果可能进一步支持增强皮层活动在 M1由 Zentgraf 和同事28发现的。最后, 由于运动任务和背景肌电图在刺激之前是相似的在两个情况下, 它被推断规定方向注意的口头指示确实有主要调制影响对皮质的活动向外国直接投资投射的抑制神经元。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/55771/55771fig1.jpg"> 
图1。四协议的时间过程.a. 前两届会议 (S1 和 S2) 的目的是将最大持续绑架右食指的时间与外部 (EF) 和关注的内部焦点 (如果) 的30% 相比较。在 EF 会话期间, 主题被要求集中在测角度 (即,运动效果), 而在 IF 会话期间, 他们被要求专注于他们的食指和肌肉 (即,身体运动)。b. 第三和第四届会议 (S3 和 S4) 旨在比较皮质抑制电路在 M1 之间的皮层活动。这可以通过比较阈 tms (subTMS) 诱导肌电图抑制的数量和持续时间, 并通过对双脉冲 tms (SICI) 诱导的近皮质抑制 (ppTMS) 的数量进行比较来实现。此图是从库恩et al16改编的。<a href="//ecsource.jove.com/files/ftp_upload/55771/55771fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/55771/55771fig2.jpg"> 
图2。实验装置.1。TMS 卷被安置在对侧 M1 在手表示法。2. 参与者的额头和 tms 线圈安装有反射标记, 以控制 tms 线圈相对于头骨的位置。3. 矫形夹板限制腕关节运动, 只允许食指运动。4. 肌电电极被放置在对外国直接投资的肌腱腹部蒙太奇。5. 测计算食指掌关节的角度。6. 代表 30% (S1 和 S2) 或 Fmax 的 10% (S3 和 S4) 的重量系在绳子上。b. 掌关节的运动显示在一个电脑屏幕上, 放置在主题前面1米。当角度为90°时, 计算机屏幕上显示的红线是最薄的。一旦参与者的手指向左或向右移动, 红线就会在相应的方向上变粗。电机任务的目的是保持红线尽可能薄。为了测量 Fmax (S1 和 S2), 力传感器被放置 (1), 使参与者可以推反对它 (即,等距收缩), 保持一个恒定的角度90°。<a href="//ecsource.jove.com/files/ftp_upload/55771/55771fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/55771/55771fig3.jpg"> 
图3。持续收缩的任务失败时间 (专题信托基金).当参与者 (n = 14) 采用外部 (EF) 而不是关注的内部焦点 (如果) 时, 该专题信托基金就延长了 (大约为 18%). * p和 #60; 0.05。误差线代表 SEM。此图是从库恩et al16改编的。<a href="//ecsource.jove.com/files/ftp_upload/55771/55771fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/55771/55771fig4.jpg"> 
图4。SubTMS 诱导的肌电信号抑制.a. 在 Fmax 10% 的右第一背骨间 (FDI) 的持续收缩过程中, 获得平均肌电图活动的曲线, 从试验中减去 subTMS 的整流肌电信号 (全整流), 而不刺激.垂直线代表 (1) subTMS 引起的肌电信号的抑制和 (2) subTMS 诱导的肌电抑制的结束。b. 代表性数据 (n = 10) subTMS 引起的肌电信号抑制量。这些数据是通过计算从起始到抑制端的累积梯形数值积分 (即,在每条曲线下的负区域从1到 2) 得到的。当外部焦点 (EF) 而不是内部焦点 (如果) 被采用时, subTMS 诱导的肌电图抑制量得到提高。c. 具有代表性的数据 (n = 10) 的 subTMS 诱导的肌电信号抑制持续时间从1到2。在抑制的持续时间内没有发现明显的差异, 但它的长度与 EF 相同。因此, 合理的假设, 影响大小太小, 导致我们的样本量相对较小的差异很大。** p和 #60; 0.01。误差线代表 SEM。此图是从库恩et al16改编的。<a href="//ecsource.jove.com/files/ftp_upload/55771/55771fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/55771/55771fig5.jpg"> 
图5。短间隔皮质抑制 (SICI).a. 在外国直接投资中, 采用以下公式表示 SICI 的百分比: 100-(条件型机电管/控制系统 x 100)。当参与者采用 EF 与 IF 相比, SICI 增强。这反映了皮质抑制电路的更大激活。b. 由于控制系统的振幅对条件型机电管的尺寸有影响, 应将两个条件 (即EF vs IF) 的控制欧洲议会议员在 1.2 aMT 峰振幅进行比较。** p和 #60; 0.01。误差线代表 SEM。此图是从库恩et al16改编的。<a href="//ecsource.jove.com/files/ftp_upload/55771/55771fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>/p >

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Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention

本文采用两种不同的经颅磁刺激 (TMS) 协议, 介绍了在采用不同的注意焦点时, 如何测量和比较初级运动皮层皮质抑制。

通过改变注意力的焦点, 可以调节皮质在初级运动皮层内的抑制

It is well recognized that an external focus (EF) compared with an internal focus (IF) of attention improves motor learning and performance. Studies have ...

intracortical-inhibition-within-primary-motor-cortex-can-be-modulated

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JoVE Journal

Behavior

9.9K 次观看.  University of Fribourg. 本文采用两种不同的经颅磁刺激 (TMS) 协议, 介绍了在采用不同的注意焦点时, 如何测量和比较初级运动皮层皮质抑制。

视频: Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention

Corticospinal Excitability Modulation During Action Observation

This study used the transcranial magnetic stimulation/motor evoked potential (TMS/MEP) technique to pinpoint when the automatic tendency to mirror someone else's action becomes anticipatory simulation of a complementary act. TMS was delivered to the left primary motor cortex corresponding to the hand to induce the highest level of MEP activity from the abductor digiti minimi (ADM; the muscle serving little finger abduction) as well as the first dorsal interosseus (FDI; the muscle serving index finger flexion/extension) muscles. A neuronavigation system was used to maintain the position of the TMS coil, and electromyographic (EMG) activity was recorded from the right ADM and FDI muscles. Producing original data with regard to motor resonance, the combined TMS/MEP technique has taken research on the perception-action coupling mechanism a step further. Specifically, it has answered the questions of how and when observing another person's actions produces motor facilitation in an onlooker's corresponding muscles and in what way corticospinal excitability is modulated in social contexts.

Single-pulse transcranial magnetic stimulation over the primary motor cortex, neuronavigation, and registration of electromyographic activity of hand muscles were used in this study to explore corticospinal excitability while participants were observing action sequences.

行动观察期间皮质脊体兴奋调节

This study used the transcranial magnetic stimulation/motor evoked potential (TMS/MEP) technique to pinpoint when the automatic tendency to mirror someone ...

科研

行为学

Measurement of Neurophysiological Signals of Ignoring and Attending Processes in Attention Control

Attention control is the ability to selectively attend to some sensory signals while ignoring others. This ability is thought to involve two processes: enhancement of sensory signals that are to be attended and the attenuation of sensory signals that are to be ignored. The overall strength of attentional modulation is often measured by comparing the amplitude of a sensory neural response to an external input when attended versus when ignored. This method is robust for detecting attentional modulation, but precludes the ability to assess the separate dynamics of attending and ignoring processes. Here, we describe methodology to measure independently the neurophysiological signals of attending and ignoring using the intermodal attention task (IMAT). This task, when combined with electroencephalography, isolates neurophysiological sensory responses in auditory and visual modalities, when either attending or ignoring, with respect to a passive control. As a result, independent dynamics of attending and of a ignoring can be assessed in either modality. Our results using this task indicate that the timing and cortical sources of attending and ignoring effects differ, as do their contributions to the attention modulation effect, pointing to unique neural trajectories and demonstrating sample utility of measuring them separately.

Attention control comprises enhancement of target signals and attenuation of distractor signals. We describe an approach to measure separately but concurrently, the neurophysiology of attending and ignoring in sustained intermodal attention, utilizing a passive control condition during which neither process is continuously engaged.

忽略并出席在注意控制过程的神经生理信号的测量

Attention control is the ability to selectively attend to some sensory signals while ignoring others. This ability is thought to involve two processes: ...

Force and Position Control in Humans - The Role of Augmented Feedback

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is constantly integrated into the central nervous system and these sensory inputs need to be weighted in order meet the task specific goals. Additional feedback presented as augmented feedback was shown to have an impact on motor control and motor learning. A number of studies investigated whether force or position feedback has an influence on motor control and neural activation. However, as in the previous studies the presentation of the force and position feedback was always identical, a recent study assessed whether not only the content but also the interpretation of the feedback has an influence on the time to fatigue of a sustained submaximal contraction and the (inhibitory) activity of the primary motor cortex using subthreshold transcranial magnetic stimulation. This paper describes one possible way to investigate the influence of the interpretation of feedback on motor behaviour by investigating the time to fatigue of submaximal sustained contractions together with the neuromuscular adaptations that can be investigated using surface EMG. Furthermore, the current protocol also describes how motor cortical (inhibitory) activity can be investigated using subthreshold TMS, a method known to act solely on the cortical level. The results show that when participants interpret the feedback as position feedback, they display a significantly shorter time to fatigue of a submaximal sustained contraction. Furthermore, subjects also displayed an increased inhibitory activity of the primary cortex when they believed to receive position feedback compared when they believed to receive force feedback. Accordingly, the results show that interpretation of feedback results in differences on a behavioural level (time to fatigue) that is also reflected in interpretation-specific differences in the amount of inhibitory M1 activity.

Controlling an identical movement with position or force feedback results in different neural activation and motor behavior. This protocol describes how to investigate behavioral changes by looking at neuromuscular fatigue and how to evaluate motor cortical (inhibitory) activity using subthreshold TMS with respect to the interpretation of augmented feedback.

力和位置控制人类 - 增强反馈的作用

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is ...

Non-invasive Assessment of Changes in Corticomotoneuronal Transmission in Humans

The corticospinal pathway is the major pathway connecting the brain with the muscles and is therefore highly relevant for movement control and motor learning. There exists a number of noninvasive electrophysiological methods investigating the excitability and plasticity of this pathway. However, most methods are based on quantification of compound potentials and neglect that the corticospinal pathway consists of many different connections that are more or less direct. Here, we present a method that allows testing excitability of different fractions of the corticospinal transmission. This so called H-reflex conditioning technique allows one to assess excitability of the fastest (monosynaptic) and also polysynaptic corticospinal pathways. Furthermore, by using two different stimulation sites, the motor cortex and the cervicomedullary junction, it allows not only differentiation between cortical and spinal effects but also assessment of transmission at the corticomotoneural synapse. In this manuscript, we describe how this method can be used to assess corticomotoneural transmission after low-frequency repetitive transcranial magnetic stimulation, a method that was previously shown to reduce excitability of cortical cells. Here we demonstrate that not only cortical cells are affected by this repetitive stimulation but also transmission at the corticomotoneuronal synapse at the spinal level. This finding is important for the understanding of basic mechanisms and sites of neuroplasticity. Besides investigation of basic mechanisms, the H-reflex conditioning technique may be applied to test changes in corticospinal transmission following behavioral (e.g., training) or therapeutic interventions, pathology or aging and therefore allows a better understanding of neural processes that underlie movement control and motor learning.

The aim of the present study was to assess changes in transmission at the corticomotoneuronal synapses in humans after repetitive transcranial magnetic stimulation. For this purpose, an electrophysiological method is introduced that allows assessment of pathway specific corticospinal transmission, i.e. differentiation of fast, direct corticospinal pathways from polysynaptic connections.

非侵入性评估人类皮质神经元传播的变化

The corticospinal pathway is the major pathway connecting the brain with the muscles and is therefore highly relevant for movement control and motor ...

神经科学

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 ...

Online Transcranial Magnetic Stimulation Protocol for Measuring Cortical Physiology Associated with Response Inhibition

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) characterization of primary motor cortex (M1) excitability and inhibition. Motor response inhibition prevents unwanted actions and is abnormal in several neuropsychiatric conditions. TMS is a non-invasive technology that can quantify M1 excitability and inhibition using single- and paired-pulse protocols and can be precisely timed to study cortical physiology with high temporal resolution. We modified the original Slater-Hammel (S-H) stop signal task to create a &#34;racecar&#34; version with TMS pulses time-locked to intra-trial events. This task is self-paced, with each trial initiating after a button push to move the racecar towards the 800 ms target. GO trials require a finger-lift to stop the racecar just before this target. Interspersed randomly are STOP trials (25%) during which the dynamically adjusted stop signal prompts subjects to prevent finger-lift. For GO trials, TMS pulses were delivered at 650 ms after trial onset; whereas, for STOP trials, the TMS pulses occurred 150 ms after the stop signal. The timings of the TMS pulses were decided based on electroencephalography (EEG) studies showing event-related changes in these time ranges during stop signal tasks. This task was studied in 3 blocks at two study sites (n=38) and we recorded behavioral performance and event-related motor-evoked potentials (MEP). Regression modelling was used to analyze MEP amplitudes using age as a covariate with multiple independent variables (sex, study site, block, TMS pulse condition [single- vs. paired-pulse], trial condition [GO, successful STOP, failed STOP]). The analysis showed that TMS pulse condition (p&#60;0.0001) and its interaction with trial condition (p=0.009) were significant. Future applications for this online S-H/TMS paradigm include the addition of simultaneous EEG acquisition to measure TMS-evoked EEG potentials. A potential limitation is that in children, the TMS pulse sound could&#160;affect behavioral task performance.

We describe an experimental procedure to quantify excitability and inhibition of primary motor cortex during a motor response inhibition task by using Transcranial Magnetic Stimulation throughout the course of a Stop Signal Task.

在线经颅磁刺激测量与反应抑制相关的皮质生理

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) ...

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 ...

Conventional and Threshold-Tracking Transcranial Magnetic Stimulation Tests for Single-handed Operation

Most single-pulse transcranial magnetic stimulation (TMS) parameters (e.g., motor threshold, stimulus-response function, cortical silent period) are used to examine corticospinal excitability. Paired-pulse TMS paradigms (e.g., short- and long-interval intracortical inhibition (SICI/LICI), short-interval intracortical facilitation (SICF), and short- and long-latency afferent inhibition (SAI/LAI)) provide information about intracortical inhibitory and facilitatory networks. This has long been done by the conventional TMS method of measuring changes in the size of the motor-evoked potentials (MEPs) in response to stimuli of constant intensity. An alternative threshold-tracking approach has recently been introduced whereby the stimulus intensity for a target amplitude is tracked. The diagnostic utility of threshold-tracking SICI in amyotrophic lateral sclerosis (ALS) has been shown in previous studies. However, threshold-tracking TMS has only been used in a few centers, in part due to the lack of readily available software but also perhaps due to uncertainty over its relationship to conventional single- and paired-pulse TMS measurements.
A menu-driven suite of semi-automatic programs has been developed to facilitate the broader use of threshold-tracking TMS techniques and to enable direct comparisons with conventional amplitude measurements. These have been designed to control three types of magnetic stimulators and allow recording by a single operator of the common single- and paired-pulse TMS protocols.
This paper shows how to record a number of single- and paired-pulse TMS protocols on healthy subjects and analyze the recordings. These TMS protocols are fast and easy to perform and can provide useful biomarkers in different neurological disorders, particularly neurodegenerative diseases such as ALS.

We present a suite of standardized single- and paired-pulse transcranial magnetic stimulation (TMS) recording protocols, with options for conventional amplitude measurements and threshold-tracking. This program can control three different types of magnetic stimulators and is designed to enable all tests to be performed conveniently by a single operator.

单手操作的常规和阈值跟踪经颅磁刺激测试

Most single-pulse transcranial magnetic stimulation (TMS) parameters (e.g., motor threshold, stimulus-response function, cortical silent period) are used ...

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.

评估目标导向到达行为期间的皮质脊髓兴奋性

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

联合周围神经刺激和可控脉搏参数 TMS

Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter Transcranial Magnetic Stimulation to Probe Sensorimotor Control and Learning

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable tool to probe the procedural and declarative influence over sensorimotor integration during skilled motor actions. This manuscript describes the methodology and contributions of short-latency afferent inhibition (SAI) for understanding sensorimotor integration. SAI quantifies the effect of a convergent afferent volley on the corticospinal motor output evoked by transcranial magnetic stimulation (TMS). The afferent volley is triggered by the electrical stimulation of a peripheral nerve. The TMS stimulus is delivered to a location over the primary motor cortex that elicits a reliable motor-evoked response in a muscle served by that afferent nerve. The extent of inhibition in the motor-evoked response reflects the magnitude of the afferent volley converging on the motor cortex and involves central GABAergic and cholinergic contributions. The cholinergic involvement in SAI makes SAI a possible marker of declarative-procedural interactions in sensorimotor performance and learning. More recently, studies have begun manipulating the TMS current direction in SAI to tease apart the functional significance of distinct sensorimotor circuits in the primary motor cortex for skilled motor actions. The ability to control additional pulse parameters (e.g., the pulse width) with state-of-the-art controllable pulse parameter TMS (cTMS) has enhanced the selectivity of the sensorimotor circuits probed by the TMS stimulus and provided an opportunity to create more refined models of sensorimotor control and learning. Therefore, the current manuscript focuses on SAI assessment using cTMS. However, the principles outlined here also apply to SAI assessed using conventional fixed pulse width TMS stimulators and other forms of afferent inhibition, such as long-latency afferent inhibition (LAI).

作者聚焦： 结合周围神经刺激和可控脉搏参数经颅磁刺激以探测感觉运动控制和学习  

Short-latency afferent inhibition (SAI) is a transcranial magnetic stimulation protocol to probe sensorimotor integration. This article describes how SAI can be used to study the convergent sensorimotor loops in the motor cortex during sensorimotor behavior.

结合周围神经刺激和可控脉搏参数经颅磁刺激探测感觉运动控制和学习

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable ...