Distinct Roles for Alpha- and Beta-Band Oscillations during Mental Simulation of Goal-Directed Actions
Distinct Roles for Alpha- and Beta-Band Oscillations during Mental Simulation of Goal-Directed Actions
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DOI：
10.1523/jneurosci.2039-14.2014
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发表时间：
2014-10-29
影响因子：
5.3
通讯作者：
Toni, Ivan
中科院分区：
文献类型：
--
作者：
Brinkman, Loek;Stolk, Arjen;Toni, Ivan
阿尔法(8-12赫兹)和贝塔(15-25赫兹)频段内的节律性神经活动在实际和想象的运动中受到调制。这些节律的变化为选择相关的神经元群体提供了一种机制，尽管这些节律的相对贡献尚不清楚。在这里，我们使用脑磁图来研究振荡功率的变化，而健康的人类参与者想象着抓住一个以不同角度定向的圆柱体。这一范式使我们能够在没有与运动执行和感觉重新传入相关的信号的情况下，研究运动模拟中涉及的神经信号。运动选择需求是通过利用这样一个事实来操纵的，即一些物体定向唤起一致的抓取动作，而另一些物体定向同时兼容上手和下手抓取。通过调节任务需求，我们展示了α-波段和β-波段节奏的功能性分离。随着运动选择需求的增加，在用于成像的同侧感觉运动皮质中，α波段振荡功率增加，而在对侧感觉运动皮质中，β波段振荡功率同时减少。当运动想象试验与对照条件进行比较时，同样的模式出现了，为这两个节律的功能分离提供了一致的证据。这些观察结果要求重新评估感觉运动节律的作用。我们认为，阿尔法波段的神经振荡通过分离与任务无关的皮质区域来调节计算资源的分配。相反，β频段中神经振荡的减少与运动参数计算中涉及的神经元群体的去抑制直接相关。
Rhythmic neural activity within the alpha (8-12 Hz) and beta (15-25 Hz) frequency bands is modulated during actual and imagined movements. Changes in these rhythms provide a mechanism to select relevant neuronal populations, although the relative contributions of these rhythms remain unclear. Here we use MEG to investigate changes in oscillatory power while healthy human participants imagined grasping a cylinder oriented at different angles. This paradigm allowed us to study the neural signals involved in the simulation of a movement in the absence of signals related to motor execution and sensory reafference. Movement selection demands were manipulated by exploiting the fact that some object orientations evoke consistent grasping movements, whereas others are compatible with both overhand and underhand grasping. By modulating task demands, we show a functional dissociation of the alpha- and beta-band rhythms. As movement selection demands increased, alpha-band oscillatory power increased in the sensorimotor cortex ipsilateral to the arm used for imagery, whereas beta-band power concurrently decreased in the contralateral sensorimotor cortex. The same pattern emerged when motor imagery trials were compared with a control condition, providing converging evidence for the functional dissociation of the two rhythms. These observations call for a re-evaluation of the role of sensorimotor rhythms. We propose that neural oscillations in the alpha-band mediate the allocation of computational resources by disengaging task-irrelevant cortical regions. In contrast, the reduction of neural oscillations in the beta-band is directly related to the disinhibition of neuronal populations involved in the computations of movement parameters.