Mu rhythm, visual processing and motor control

作者：Sabate Magdalena; Llanos Catalina; Enriquez Enrique; Rodriguez Manuel^*

来源：Clinical Neurophysiology, 2012, 123(3): 550-557.

DOI：10.1016/j.clinph.2011.07.034

• Mu activity
• Sensorimotor cortex
• Idling hypothesis

Objective: The Mu-rhythm has been proposed as both an inhibitor (%26quot;idling hypothesis%26quot;) and as a promoter (%26quot;processing hypothesis%26quot;) 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. %26lt;br%26gt;Methods: 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 alpha-range (Mu-alpha) and beta-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). %26lt;br%26gt;Results: Visual stimuli induced a phase-locked alpha-oscillation which began approximate to 50 ms after the stimulus onset and persisted for about 150-200 ms. This response was much higher when stimuli were used for motion planning than when they were passively observed, and was more marked in the alpha-range than in the beta-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. %26lt;br%26gt;Conclusions: 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. %26lt;br%26gt;Significance: Present data suggest that Mu-activity performs a double action, increasing the information processing of one task (according to the %26quot;processing hypothesis%26quot;) and decreasing the computation of other potentially interfering tasks (according to the %26quot;idling hypothesis%26quot;), with task selection being achieved by choosing their phase-association to the Mu-wave.

• 出版日期2012-3