Research Institute MOVE, VU University Amsterdam, Amsterdam, the Netherlands.
Cereb Cortex. 2010 Nov;20(11):2605-13. doi: 10.1093/cercor/bhq008. Epub 2010 Feb 22.
Bimanual coordination requires the functional integration of the activity in various cortical, subcortical, spinal, and peripheral neural structures. We challenged this functional integration by destabilizing bimanual 5:8 tapping through an increase in movement tempo, while measuring brain and muscle activity using magnetoencephalography and electromyography. Movement instabilities were characterized by a drop in frequency locking. Time-frequency analysis revealed movement-related beta amplitude modulation in bilateral motor areas as well as movement-related corticospinal entrainment. Both of these synchronization patterns depended on movement tempo suggesting that the timescale needed for the upregulation and downregulation of beta synchrony in rhythmic tapping poses constraints on motor performance. Bilateral phase locking over movement cycles appeared to be mediated by beta-frequency oscillations and constrained by its phase dynamics. The timescale of beta synchrony thus seems to play a key role in achieving timed phase synchrony in the motor cortex and along the neural axis. Once event-related desynchronization-synchronization cycles cannot be build up properly, inhibition may become inadequate, resulting in a reduction of the stability of performance, which may eventually become unstable.
双手协调需要各种皮质、皮质下、脊髓和外周神经结构的活动进行功能整合。我们通过增加运动节奏来破坏双手 5:8 轻敲的这种功能整合，同时使用脑磁图和肌电图测量大脑和肌肉的活动。运动不稳定性的特征是频率锁定下降。时频分析显示双侧运动区的运动相关β波振幅调制以及运动相关皮质脊髓同步。这两种同步模式都依赖于运动节奏，这表明在节奏轻敲中上调和下调β同步所需的时间尺度对运动表现构成了限制。运动周期中的双边相位锁定似乎是由β频率振荡介导的，并受到其相位动力学的限制。因此，β同步的时间尺度似乎在实现运动皮层和沿神经轴的定时相位同步方面起着关键作用。一旦事件相关去同步-同步循环不能正常建立，抑制可能会不足，导致运动表现稳定性降低，最终可能变得不稳定。
