β-Bursts Reveal the Trial-to-Trial Dynamics of Movement Initiation and Cancellation
β-Bursts Reveal the Trial-to-Trial Dynamics of Movement Initiation and Cancellation
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DOI：
10.1523/jneurosci.1887-19.2019
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发表时间：
2020-01-08
影响因子：
5.3
通讯作者：
Wessel, Jan R.
中科院分区：
文献类型：
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作者：
Wessel, Jan R.
基础研究人员和临床医生都对运动控制的神经生理学基础非常感兴趣。运动过程伴随着贝塔频段(15-29赫兹)的显著场电位变化：在试验平均值中，运动启动伴随着感觉运动区的贝塔频段去同步，而运动取消伴随着额区(前)的贝塔功率增加。然而，平均化错误地反映了贝塔信号的真实性质。未平均的β波段活动的特点是持续时间短、爆发式事件，而不是稳定的调制。因此，基于平均值的量化可能会错过重要的大脑-行为关系。为了研究男性和女性(N=234)的β-爆发与运动的关系，我们研究了在停止信号任务中头皮记录的β-带活动，该任务同时操作了运动的启动和取消。这两个过程都通过系统的β-爆发率的时空变化来索引。在运动开始前，双侧感觉运动部位的β-爆发率较高。这些爆发率预测了反应时间(这种关系在试验平均数据中是不存在的)，这表明感觉运动β-爆发意味着运动系统受到抑制，必须克服这种系统才能启动运动。事实上，在动作开始的过程中，感觉运动爆发率稳步下降，在动作执行前呈偏侧化。相反，成功的运动取消标志着额叶中央部位的β-爆发期增加。在这种β-爆发率之后，双侧感觉运动β-爆发率的潜伏期短时间增加，这表明当运动必须迅速取消时，运动抑制可以通过额区迅速重新激活。总而言之，这些发现表明，β-爆发是运动系统的一个基本标志，感觉运动和额叶区域都使用，参与对行为的逐次尝试控制。
The neurophysiological basis of motor control is of substantial interest to basic researchers and clinicians alike. Motor processes are accompanied by prominent field potential changes in the beta-frequency band (15-29 Hz): in trial-averages, movement initiation is accompanied by beta-band desynchronization over sensorimotor areas, whereas movement cancellation is accompanied by beta -power increases over , (pre)frontal areas. However, averaging misrepresents the true nature of the beta-signal. Unaveraged beta-band activity is characterized by short-lasting, burst-like events, rather than by steady modulations. Therefore, averaging-based quantifications may miss important brain-behavior relationships. To investigate how beta-bursts relate to movement in male and female humans (N = 234), we investigated scalp-recorded beta-band activity during the stop-signal task, which operationalizes both movement initiation and cancellation. Both processes were indexed by systematic spatiotemporal changes in beta-burst rates. Before movement initiation, beta-bursting was prominent at bilateral sensorimotor sites. These burst-rates predicted reaction time (a relationship that was absent in trial-average data), suggesting that sensorimotor beta-bursting signifies an inhibited motor system, which has to be overcome to initiate movements. Indeed, during movement initiation, sensorimotor burst-rates steadily decreased, lateralizing just before movement execution. In contrast, successful movement cancellation was signified by increased phasic beta-bursting over fronto-central sites. Such beta-bursts were followed by short latency increases of bilateral sensorimotor beta-burst rates, suggesting that motor inhibition can be rapidly re-instantiated by frontal areas when movements have to be rapidly cancelled. Together, these findings suggest that beta-bursting is a fundamental signature of the motor system, used by both sensorimotor and frontal areas involved in the trial-by-trial control of behavior.