Rehabilitation Service, Department of Pharmacology and Physical Medicine, Faculty of Medicine, University of La Laguna, Tenerife, Canary Islands, Spain.
Clin Neurophysiol. 2012 Mar;123(3):550-7. doi: 10.1016/j.clinph.2011.07.034. Epub 2011 Aug 12.
The Mu-rhythm has been proposed as both an inhibitor ("idling hypothesis") and as a promoter ("processing hypothesis") of information processing in the primary sensory-motor cortex (SM-C). We tested these possibilities by analyzing the phase-locked and non-phase-locked Mu response during the execution of a visual-motor task.
EEG was recorded in 13 subjects during the visual presentation of an arrow which indicated the direction of the finger motion to be executed after the presentation of a second stimulus. The EEG activity in the α-range (Mu-α) and β-range was evaluated by a method which segregated the phase-locked and the non-phase-locked response. The event-related Mu-response observed during this task was compared with that computed when the subjects saw the same arrow-stimuli but did not perform any task (passive test).
Visual stimuli induced a phase-locked α-oscillation which began ≈50ms after the stimulus onset and persisted for about 150-200ms. This response was much higher when stimuli were used for motion planning than when they were passively observed, and was more marked in the α-range than in the β-range. The phase-locked response was followed by a persistent decrease of the non-phase-locked Mu-activity similar to that previously reported with the event-related desynchronization/synchronization method.
The Mu-wave is not a single phenomenon. It was segregated here into two components, one with an early and short-lasting phase locked-response to visual stimuli, which increased during the task execution, and the other without phase-locked responses which persistently decreased during the task execution.
Present data suggest that Mu-activity performs a double action, increasing the information processing of one task (according to the "processing hypothesis") and decreasing the computation of other potentially interfering tasks (according to the "idling hypothesis"), with task selection being achieved by choosing their phase-association to the Mu-wave.
Mu 节律被提出既是信息处理的抑制剂（“空闲假说”），又是促进剂（“处理假说”），在初级感觉运动皮层（SM-C）中。我们通过分析执行视觉运动任务期间的锁相和非锁相 Mu 响应来检验这些可能性。
在视觉呈现箭头指示要执行的手指运动方向之后，在 13 个受试者中记录 EEG。通过一种分离锁相和非锁相响应的方法评估 α 范围（Mu-α）和 β 范围的 EEG 活动。在执行此任务期间观察到的事件相关 Mu 响应与受试者看到相同箭头刺激但不执行任何任务（被动测试）时计算的响应进行比较。
视觉刺激诱导约 50ms 后开始并持续约 150-200ms 的锁相α 振荡。当刺激用于运动规划时，该响应比被动观察时高得多，并且在α范围比β范围更明显。锁相响应之后是持续的非锁相 Mu 活动的持续减少，类似于先前使用事件相关去同步/同步方法报告的情况。
Mu 波不是单一现象。在这里，它被分为两个组成部分，一个是对视觉刺激具有早期和短暂持续的锁相响应，该响应在任务执行过程中增加，另一个是没有锁相响应的 Mu 波持续减少，这表明 Mu 活动在执行任务时会进行双重作用，增加了一项任务的信息处理（根据“处理假说”），减少了其他潜在干扰任务的计算（根据“空闲假说”），通过选择它们与 Mu 波的相位关联来实现任务选择。
目前的数据表明，Mu 活动执行双重作用，增加一项任务的信息处理（根据“处理假说”），减少其他潜在干扰任务的计算（根据“空闲假说”），通过选择它们与 Mu 波的相位关联来实现任务选择。
