Cebolla Ana-Maria, Palmero-Soler Ernesto, Leroy Axelle, Cheron Guy
Laboratory of Neurophysiology and Movement Biomechanics, Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium.
Laboratory of Electrophysiology, Université de Mons, Mons, Belgium.
Front Psychol. 2017 Dec 12;8:2133. doi: 10.3389/fpsyg.2017.02133. eCollection 2017.
In order to characterize the neural generators of the brain oscillations related to motor imagery (MI), we investigated the cortical, subcortical, and cerebellar localizations of their respective electroencephalogram (EEG) spectral power and phase locking modulations. The MI task consisted in throwing a ball with the dominant upper limb while in a standing posture, within an ecological virtual reality (VR) environment (tennis court). The MI was triggered by the visual cues common to the control condition, during which the participant remained mentally passive. As previously developed, our paradigm considers the confounding problem that the reference condition allows two complementary analyses: one which uses the baseline before the occurrence of the visual cues in the MI and control resting conditions respectively; and the other which compares the analog periods between the MI and the control resting-state conditions. We demonstrate that MI activates specific, complex brain networks for the power and phase modulations of the EEG oscillations. An early (225 ms) delta phase-locking related to MI was generated in the thalamus and cerebellum and was followed (480 ms) by phase-locking in theta and alpha oscillations, generated in specific cortical areas and the cerebellum. Phase-locking preceded the power modulations (mainly alpha-beta ERD), whose cortical generators were situated in the frontal BA45, BA11, BA10, central BA6, lateral BA13, and posterior cortex BA2. Cerebellar-thalamic involvement through phase-locking is discussed as an underlying mechanism for recruiting at later stages the cortical areas involved in a cognitive role during MI.
为了表征与运动想象(MI)相关的脑振荡的神经发生器,我们研究了其各自脑电图(EEG)频谱功率和锁相调制在皮质、皮质下和小脑的定位。MI任务包括在生态虚拟现实(VR)环境(网球场)中站立姿势下用优势上肢投球。MI由与对照条件共有的视觉线索触发,在此期间参与者保持精神被动。如先前开发的那样,我们的范式考虑了参考条件允许两种互补分析的混杂问题:一种是分别使用MI和对照静息条件下视觉线索出现之前的基线;另一种是比较MI和对照静息状态条件之间的类似时间段。我们证明,MI激活了用于EEG振荡功率和相位调制的特定复杂脑网络。与MI相关的早期(225毫秒)δ波锁相在丘脑和小脑中产生,随后(480毫秒)在特定皮质区域和小脑中产生θ波和α波振荡的锁相。锁相先于功率调制(主要是α-β事件相关去同步化),其皮质发生器位于额叶BA45、BA11、BA10、中央BA6、外侧BA13和后皮质BA2。通过锁相的小脑-丘脑参与被讨论为在后期招募MI期间参与认知作用的皮质区域的潜在机制。