Department of Speech-Language Pathology, University of Toronto, Ontario, Canada.
Rehabilitation Sciences Institute, University of Toronto, Ontario, Canada.
J Speech Lang Hear Res. 2021 Jun 18;64(6S):2248-2260. doi: 10.1044/2021_JSLHR-20-00275. Epub 2021 Apr 23.
Purpose The planning and execution of motor behaviors require coordination of neurons that are established through synchronization of neural activity. Movements are typically preceded by event-related desynchronization (ERD) in the beta range (15-30 Hz) primarily localized in the motor cortex, while movement onset is associated with event-related synchronization (ERS). It is hypothesized that ERD is important for movement preparation and execution, and ERS serves to inhibit movement and update the motor plan. The primary objective of this study was to determine to what extent movement-related oscillatory brain patterns (ERD and ERS) during verbal and nonverbal tasks may be affected differentially by variations in task complexity. Method Seventeen right-handed adult participants (nine women, eight men; = 25.8 years, = 5.13) completed a sequential button press and verbal task. The final analyses included data for 15 participants for the nonverbal task and 13 for the verbal task. Both tasks consisted of two complexity levels: simple and complex sequences. Magnetoencephalography was used to record modulations in beta band brain oscillations during task performance. Results Both the verbal and button press tasks were characterized by significant premovement ERD and postmovement ERS. However, only simple sequences showed a distinct transient synchronization during the premovement phase of the task. Differences between the two tasks were reflected in both latency and peak amplitude of ERD and ERS, as well as in lateralization of oscillations. Conclusions Both verbal and nonverbal movements showed a significant desynchronization of beta oscillations during the movement preparation and holding phase and a resynchronization upon movement termination. Importantly, the premovement phase for simple but not complex tasks was characterized by a transient partial synchronization. In addition, the data revealed significant differences between the two tasks in terms of lateralization of oscillatory modulations. Our findings suggest that, while data from the general motor control research can inform our understanding of speech motor control, significant differences exist between the two motor systems that caution against overgeneralization of underlying neural control processes.
运动行为的计划和执行需要通过神经元的同步来协调，而神经元的同步则是通过神经活动的同步建立的。运动通常以前额叶皮质中主要定位的 beta 频段（15-30Hz）的事件相关去同步（ERD）为先导，而运动起始则与事件相关同步（ERS）相关。据推测，ERD 对于运动准备和执行很重要，ERS 则用于抑制运动并更新运动计划。本研究的主要目的是确定在言语和非言语任务中，与运动相关的振荡脑模式（ERD 和 ERS）在多大程度上可能因任务复杂性的变化而受到不同程度的影响。
17 名右利手成年参与者（9 名女性，8 名男性；平均年龄 25.8 岁，标准差 5.13）完成了连续按钮按压和言语任务。最终分析包括 15 名参与者的非言语任务数据和 13 名参与者的言语任务数据。两个任务都包括两个复杂程度水平：简单和复杂序列。使用脑磁图记录任务执行过程中 beta 波段脑振荡的调制。
言语和按钮按压任务都表现出明显的运动前 ERD 和运动后 ERS。然而，只有简单序列在任务的运动前阶段显示出明显的短暂同步。两个任务之间的差异反映在 ERD 和 ERS 的潜伏期和峰值幅度以及振荡的偏侧化上。
言语和非言语运动都表现出在运动准备和保持阶段 beta 振荡的显著去同步和运动终止后的再同步。重要的是，简单任务而非复杂任务的运动前阶段的特征是短暂的部分同步。此外，数据显示两个任务在振荡调制的偏侧化方面存在显著差异。我们的发现表明，虽然来自一般运动控制研究的数据可以为我们理解言语运动控制提供信息，但两个运动系统之间存在显著差异，这提醒我们不要对潜在的神经控制过程进行过度概括。
