Toma Keiichiro, Mima Tatsuya, Matsuoka Takahiro, Gerloff Christian, Ohnishi Tatsuhito, Koshy Benjamin, Andres Frank, Hallett Mark
Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-1428, USA.
J Neurophysiol. 2002 Dec;88(6):3377-85. doi: 10.1152/jn.00281.2002.
We investigated changes in the activation and functional coupling of bilateral primary sensorimotor (SM1) and supplementary motor (SMA) areas with different movement rates in eight normal volunteers. An auditory-cued repetitive right-thumb movement was performed at rates of 0.5, 0.75, 1, 2, 3, and 4 Hz. As a control condition, subjects listened to pacing tones with no movements. Electroencephalogram (EEG) was recorded from 28 scalp electrodes and electromyogram was obtained from the hand muscles. The event-related changes in EEG band-power (ERpow: activation of each area) and correlation (ERcor: functional coupling between each pair of cortical areas) were computed every 32 ms. Modulations of ERpow and ERcor were inspected in alpha (8-12 Hz) and beta (16-20 Hz) bands. Motor cortical activation and coupling was greater for faster movements. With increasing movement rate, the timing relationship between movement and tone switched from synchronization (for 0.5-1 Hz) to syncopation (for 3-4 Hz). The results suggested that for slow repetitive movements (0.5-1 Hz), each individual movement is separately controlled, and EEG activation and coupling of the motor cortical areas were immediately followed by transient deactivation and decoupling, having clear temporal modulation locked to each movement. In contrast, for fast repetitive movements (3-4 Hz), it appears that the rhythm is controlled and the motor cortices showed sustained EEG activation and continuous coupling.
我们研究了8名正常志愿者在不同运动速率下双侧初级感觉运动区（SM1）和辅助运动区（SMA）的激活及功能耦合变化。以0.5、0.75、1、2、3和4赫兹的速率进行听觉提示的重复性右拇指运动。作为对照条件，受试者在不做运动的情况下听节拍音。从28个头皮电极记录脑电图（EEG），并从手部肌肉获取肌电图。每32毫秒计算一次脑电图频段功率（ERpow：每个区域的激活）和相关性（ERcor：每对皮质区域之间的功能耦合）的事件相关变化。在α（8 - 12赫兹）和β（16 - 20赫兹）频段检查ERpow和ERcor的调制情况。运动皮层的激活和耦合在更快的运动时更强。随着运动速率增加，运动与节拍音之间的时间关系从同步（0.5 - 1赫兹）转变为切分音（3 - 4赫兹）。结果表明，对于缓慢的重复性运动（0.5 - 1赫兹），每个单独的运动是分别控制的，运动皮层区域的脑电图激活和耦合之后紧接着是短暂的失活和解耦，具有与每个运动锁定的清晰时间调制。相比之下，对于快速的重复性运动（3 - 4赫兹），似乎节律是被控制的，运动皮层显示出持续的脑电图激活和持续的耦合。
