Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.
Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
J Neurophysiol. 2021 Mar 1;125(3):938-956. doi: 10.1152/jn.00530.2020. Epub 2021 Feb 10.
Magnetoencephalography (MEG) is a technique used to measure the magnetic fields generated from neuronal activity in the brain. MEG has a high temporal resolution on the order of milliseconds and provides a more direct measure of brain activity when compared with hemodynamic-based neuroimaging methods such as magnetic resonance imaging and positron emission tomography. The current review focuses on basic features of MEG such as the instrumentation and the physics that are integral to the signals that can be measured, and the principles of source localization techniques, particularly the physics of beamforming and the techniques that are used to localize the signal of interest. In addition, we review several metrics that can be used to assess functional coupling in MEG and describe the advantages and disadvantages of each approach. Lastly, we discuss the current and future applications of MEG.
脑磁图（MEG）是一种用于测量大脑神经元活动产生的磁场的技术。MEG 具有毫秒级的高时间分辨率，与基于血流动力学的神经影像学方法（如磁共振成像和正电子发射断层扫描）相比，提供了更直接的大脑活动测量方法。本综述重点介绍了 MEG 的基本特征，如仪器和物理特性，这些都是可以测量的信号所必需的，以及源定位技术的原理，特别是波束形成的物理原理和用于定位感兴趣信号的技术。此外，我们还回顾了可用于评估 MEG 中功能耦合的几种度量，并描述了每种方法的优缺点。最后，我们讨论了 MEG 的当前和未来应用。
