Rotman Research Institute, Baycrest Centre, Toronto, Ontario M6A 2E1, Canada.
J Neurosci. 2012 Feb 1;32(5):1791-802. doi: 10.1523/JNEUROSCI.4107-11.2012.
Moving in synchrony with an auditory rhythm requires predictive action based on neurodynamic representation of temporal information. Although it is known that a regular auditory rhythm can facilitate rhythmic movement, the neural mechanisms underlying this phenomenon remain poorly understood. In this experiment using human magnetoencephalography, 12 young healthy adults listened passively to an isochronous auditory rhythm without producing rhythmic movement. We hypothesized that the dynamics of neuromagnetic beta-band oscillations (~20 Hz)-which are known to reflect changes in an active status of sensorimotor functions-would show modulations in both power and phase-coherence related to the rate of the auditory rhythm across both auditory and motor systems. Despite the absence of an intention to move, modulation of beta amplitude as well as changes in cortico-cortical coherence followed the tempo of sound stimulation in auditory cortices and motor-related areas including the sensorimotor cortex, inferior-frontal gyrus, supplementary motor area, and the cerebellum. The time course of beta decrease after stimulus onset was consistent regardless of the rate or regularity of the stimulus, but the time course of the following beta rebound depended on the stimulus rate only in the regular stimulus conditions such that the beta amplitude reached its maximum just before the occurrence of the next sound. Our results suggest that the time course of beta modulation provides a mechanism for maintaining predictive timing, that beta oscillations reflect functional coordination between auditory and motor systems, and that coherence in beta oscillations dynamically configure the sensorimotor networks for auditory-motor coupling.
与听觉节奏同步运动需要基于时间信息的神经动力学表示进行预测性动作。虽然已知有规律的听觉节奏可以促进节奏运动，但这种现象的神经机制仍知之甚少。在这项使用人类脑磁图的实验中，12 名年轻健康的成年人被动地听等时听觉节奏，而不产生节奏运动。我们假设，神经磁β波段振荡的动力学（约 20 Hz）——已知反映感觉运动功能活跃状态的变化——将在听觉和运动系统中都表现出与听觉节奏速率相关的功率和相位相干性的调制。尽管没有移动的意图，但在听觉皮层和运动相关区域（包括感觉运动皮层、下额前回、辅助运动区和小脑）中，β 振幅的调制以及皮质间相干性的变化都跟随声音刺激的节奏。β 振幅在刺激后下降的时间过程与刺激的速率或规律性无关，但β 反弹的时间过程仅在规则刺激条件下取决于刺激速率，即β 振幅在下次声音出现之前达到最大值。我们的结果表明，β 调制的时间过程为维持预测性时间提供了一种机制，β 振荡反映了听觉和运动系统之间的功能协调，β 振荡的相干性动态地为听觉-运动耦合配置感觉运动网络。
