CoActions Lab, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
CoActions Lab, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
Neuroimage. 2020 Jun;213:116746. doi: 10.1016/j.neuroimage.2020.116746. Epub 2020 Mar 18.
The motor system displays strong changes in neural activity during action preparation. In the past decades, several techniques, including transcranial magnetic stimulation (TMS), electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), have allowed us to gain insights into the functional role of such preparatory activity in humans. More recently, new TMS tools have been proposed to study the mechanistic principles underlying the changes in corticospinal excitability during action preparation. The aim of the present review is to provide a comprehensive description of these advanced methods and to discuss the new knowledge they give access to, relative to other existing approaches. We start with a brief synthesis of the work that has been achieved so far using classic TMS protocols during action preparation, such as the so-called single-pulse and paired-pulse techniques. We then highlight three new approaches that recently arose in the field of action preparation, including (1) the exploitation of TMS current direction, known as directional TMS, which enables investigating different subsets of neurons in the primary motor cortex, (2) the use of paired-pulse TMS to study the suppressive influence of the cerebellum on corticospinal excitability and (3) the development of a double-coil TMS approach, which facilitates the study of bilateral changes in corticospinal excitability. The aim of the present article is twofold: we seek to provide a comprehensive description of these advanced TMS tools and to discuss their bearings for the field of action preparation with respect to more traditional TMS approaches, as well as to neuroimaging techniques such as EEG or fMRI. Finally, we point out perspectives for fundamental and clinical research that arise from the combination of these methods, widening the horizon of possibilities for the investigation of the human motor system, both in health and disease.
运动系统在动作准备过程中显示出强烈的神经活动变化。在过去的几十年中，包括经颅磁刺激（TMS）、脑电图（EEG）和功能磁共振成像（fMRI）在内的几种技术使我们能够深入了解这种预备活动在人类中的功能作用。最近，提出了新的 TMS 工具来研究在动作准备过程中皮质脊髓兴奋性变化的机制原理。本综述的目的是全面描述这些先进方法，并讨论与其他现有方法相比，它们提供的新知识。我们首先简要总结了迄今为止在动作准备过程中使用经典 TMS 方案所取得的工作，例如所谓的单脉冲和双脉冲技术。然后，我们强调了动作准备领域中最近出现的三种新方法，包括（1）利用 TMS 电流方向，称为定向 TMS，这使我们能够研究初级运动皮层中不同的神经元子集，（2）使用双脉冲 TMS 研究小脑对皮质脊髓兴奋性的抑制影响，以及（3）开发双线圈 TMS 方法，这有助于研究皮质脊髓兴奋性的双侧变化。本文的目的有两个：我们旨在全面描述这些先进的 TMS 工具，并讨论它们相对于传统 TMS 方法以及 EEG 或 fMRI 等神经影像学技术在动作准备领域的意义。最后，我们指出了这些方法结合所带来的基础和临床研究的前景，拓宽了研究人类运动系统的可能性，无论是在健康还是疾病方面。
