Ricci Serena, Tatti Elisa, Mehraram Ramtin, Panday Priya, Ghilardi M Felice
IEEE Int Conf Rehabil Robot. 2019 Jun;2019:1254-1259. doi: 10.1109/ICORR.2019.8779373.
Movement is associated with power changes over sensory-motor areas in different frequency ranges, including beta (15-30 Hz). In fact, beta power starts decreasing before the movement onset (event-related desynchronization, ERD) and rebounds after its end (event-related synchronization, ERS). There is increasing evidence that beta modulation depth (measured as ERD-ERS difference) increases with practice in a planar reaching task, suggesting that this measure may reflect plasticity processes. In the present work, we analyzed beta ERD, ERS and modulation depth in healthy subjects to determine their changes over three regions of interest (ROIs): right and left sensorimotor and frontal areas, during a reaching task with the right arm. We found that ERD, ERS and modulation depth increased with practice with lower values over the right sensory-motor area. Timing of peak ERD and ERS were similar across ROIs, with ERS peak occurring earlier in later sets. Finally, we found that beta ERS of the frontal ROI involved higher beta range (23-29 Hz) than the sensory-motor ROIs (15-18 Hz). Altogether these results suggest that practice in a reaching task is associated with modification of beta power and timing. Additionally, beta ERS may have different functional meaning in the three ROIs, as suggested by the involvement of upper and lower beta bands in the frontal and sensorimotor ROIs, respectively.
运动与不同频率范围内感觉运动区域的功率变化相关，包括β波（15 - 30赫兹）。事实上，β波功率在运动开始前就开始下降（事件相关去同步化，ERD），并在运动结束后反弹（事件相关同步化，ERS）。越来越多的证据表明，在平面伸手任务中，随着练习的增加，β波调制深度（以ERD - ERS差异衡量）会增加，这表明该指标可能反映了可塑性过程。在本研究中，我们分析了健康受试者的β波ERD、ERS和调制深度，以确定它们在三个感兴趣区域（ROI）中的变化：右侧和左侧感觉运动区以及额叶区，在右臂进行伸手任务期间。我们发现，随着练习的增加，ERD、ERS和调制深度增加，右侧感觉运动区的值较低。不同ROI的ERD和ERS峰值时间相似，后期组的ERS峰值出现得更早。最后，我们发现额叶ROI的β波ERS涉及的β波范围（23 - 29赫兹）比感觉运动ROI（15 - 18赫兹）更高。总之，这些结果表明伸手任务中的练习与β波功率和时间的改变有关。此外，如额叶和感觉运动ROI分别涉及较高和较低β波段所示，β波ERS在三个ROI中可能具有不同的功能意义。
