Lateralization of event-related beta desynchronization in the EEG during pre-cued reaction time tasks
Lateralization of event-related beta desynchronization in the EEG during pre-cued reaction time tasks
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DOI：
10.1016/j.clinph.2005.03.017
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发表时间：
2005-08-01
影响因子：
4.7
通讯作者：
Brown, P
中科院分区：
文献类型：
--
作者：
Doyle, LMF;Yarrow, K;Brown, P
目的：研究β (13-30 Hz)频率范围内皮质脑电频谱成分的事件相关去同步（ERD）是否可能在一定程度上反映运动选择过程。具体而言，我们寻找了β ERD的对侧主导成分的证据，该成分仅限于在任何必要的移动提示之前可能进行运动选择的试验，并伴有行为优势。方法：我们测量了12名健康志愿者的反应时间，并评估了他们在执行预先提示选择反应时间任务时β ERD的偏侧性，在这些任务中，警告S1提示要么完全预测随后的强制性S2信号的偏侧性，要么不提供偏侧性信息。我们计算了“侧化ERD指数”（LERDI），这是时域侧化准备电位的平行度量。结果：100% S1-S2一致性的试验比50% S1-S2一致性的试验产生的反应时间明显短，其中侧面信息是不可靠的。β - LERDI显示，与50%条件相比，100%条件下运动后的ERD和事件相关同步（ERS）在警告-go间隔内的侧化明显更大。即使受试者被指示做出与提示相反的侧向运动，手的- ERD偏侧化仍然存在。结论：运动前S1-S2期的β带发生侧侧脑电图变化，但仅当信息警告提示允许早期运动选择时，反应时间缩短。此外，100% S1-S2一致性的对侧ERS增强表明，这种现象至少部分独立于传入反馈，因为在100%和50%的条件下也进行了相同的运动。意义：在外部产生运动之前，β功率的侧化抑制与运动选择有关。(c) 2005年国际临床神经生理学联合会。爱思唯尔爱尔兰有限公司出版。版权所有。
Objective: Here, we investigate whether the event-related desynchronization (ERD) of spectral components of the cortical EEG in the beta (13-30 Hz) frequency range may, in part, index motor selection processes. Specifically, we sought evidence for a contralaterally dominant component of the beta ERD that is limited to trials in which motor selection is possible prior to any imperative cue to move, with attendant behavioural advantage.Methods: We measured reaction time and assessed the lateralization of beta ERD in 12 healthy volunteers as they performed pre-cued choice reaction time tasks, in which warning S1 cues were either fully predictive about the laterality of a subsequent imperative S2 signal or provided no laterality information. We calculated 'lateralized ERD index' (LERDI), a parallel measure to the lateralized readiness potential in the time domain.Results: Trials with 100% S1-S2 congruency produced significantly shorter reaction times than trials with 50% S1-S2 congruency, where laterality information was unreliable. Beta LERDI indicated significantly greater lateralisation of the ERD in the warning-go interval and of event-related synchronization (ERS) following movement in the 100% condition than in the 50% condition. The lateralization of the beta ERD with respect to hand persisted, even when subjects were instructed to make movements of opposite laterality to those prompted.Conclusions: Lateralized EEG changes occur in the beta band in the S1-S2 interval prior to movement, but only when informative warning cues allow early motor selection, as suggested by the shortening of reaction time. Furthermore, the enhanced contralateral ERS with 100% S1-S2 congruency suggests that this phenomenon is at least partly independent of afferent feedback, as the same movement was made in the 100 and 50% conditions.Significance: Lateralized suppression of beta power prior to externally generated movements is associated with motor selection. (c) 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.