Department of Biomedical Engineering and Computational Science, Aalto University School of Science Espoo, Finland ; BioMag Laboratory, HUSLAB, Helsinki University Central Hospital Helsinki, Finland.
Front Hum Neurosci. 2013 Apr 25;7:155. doi: 10.3389/fnhum.2013.00155. eCollection 2013.
To improve our understanding of the combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) method in general, it is important to study how the dynamics of the TMS-modulated brain activity differs from the dynamics of spontaneous activity. In this paper, we introduce two quantitative measures based on EEG data, called mean state shift (MSS) and state variance (SV), for evaluating the TMS-evoked changes in the brain-state dynamics. MSS quantifies the immediate TMS-elicited change in the brain state, whereas SV shows whether the rate at which the brain state changes is modulated by TMS. We report a statistically significant increase for a period of 100-200 ms after the TMS pulse in both MSS and SV at the group level. This indicates that the TMS-modulated brain state differs from the spontaneous one. Moreover, the TMS-modulated activity is more vigorous than the natural activity.
为了提高我们对经颅磁刺激（TMS）和脑电图（EEG）联合方法的理解，研究 TMS 调制的脑活动动力学与自发活动动力学的差异非常重要。在本文中，我们引入了两个基于 EEG 数据的定量指标，称为平均状态偏移（MSS）和状态方差（SV），用于评估 TMS 诱发的脑状态动力学变化。MSS 量化了 TMS 引发的脑状态的即时变化，而 SV 则显示了脑状态变化的速度是否受到 TMS 的调制。我们报告了在 TMS 脉冲后 100-200 毫秒的时间段内，MSS 和 SV 在组水平上均有显著增加。这表明 TMS 调制的脑状态与自发状态不同。此外，TMS 调制的活动比自然活动更为活跃。
