EEG alpha activity reflects motor preparation rather than the mode of action selection
EEG alpha activity reflects motor preparation rather than the mode of action selection
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DOI：
10.3389/fnint.2012.00059
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发表时间：
2012-01-01
影响因子：
3.5
通讯作者：
Ibanez, Vicente
中科院分区：
文献类型：
--
作者：
Deiber, Marie-Pierre;Sallard, Etienne;Ibanez, Vicente
α -波段活动（8-13 Hz）不仅受到感觉刺激和运动的抑制，还受到注意、工作记忆和心理任务的调节，并可能对高级运动控制功能敏感。本研究的目的是检查在准备简单的左手或右手手指动作时的α振荡活动，对比外部和内部的动作选择模式。采用以Si为预备、S2为祈使提示的前置范式考察了三种制备条件：Si指示的充分、侧向性；自由，侧向性自由选择，无，侧向性由S2指示。在S1 - S2区间的α频率范围内进行时频（IF）分析，并计算α运动相关振幅不对称性（MRAA）。在完全和自由状态下显著的MRAA表明有效的外部和内部运动反应准备。在没有特定运动准备（None）的情况下，后路α事件相关失同步（ERD）占主导地位，反映了注意资源的主要参与。在充分运动准备和自由运动准备中，后α ERD伴随着中顶叶α事件相关同步（ERS），表明同时抑制了与任务无关的视觉活动。在充分运动准备和自由运动准备中，根据MRAA振幅分析α功率揭示了两种功能激活模式：(1)运动α模式，以中顶叶α - ERS为主，大的MRAA对应于侧化的运动激活/视觉抑制；(2)注意α模式，以右侧后α ERD为主，小的MRAA反映视觉空间注意。目前的结果表明，α振荡模式不解决选择模式的行动，而是区分单独的功能策略的运动准备。
Alpha-band activity (8-13 Hz) is not only suppressed by sensory stimulation and movements, but also modulated by attention, working memory and mental tasks, and could be sensitive to higher motor control functions. The aim of the present study was to examine alpha oscillatory activity during the preparation of simple left or right finger movements, contrasting the external and internal mode of action selection. Three preparation conditions were examined using a precueing paradigm with Si as the preparatory and S2 as the imperative cue: Full, laterality instructed by Si; Free, laterality freely selected and None, laterality instructed by S2. Time-frequency (IF) analysis was performed in the alpha frequency range during the S1 S2 interval, and alpha motor-related amplitude asymmetries (MRAA) were also calculated. The significant MRAA during the Full and Free conditions indicated effective external and internal motor response preparation. In the absence of specific motor preparation (None), a posterior alpha event-related desynchronization (ERD) dominated, reflecting the main engagement of attentional resources. In Full and Free motor preparation, posterior alpha ERD was accompanied by a midparietal alpha event-related synchronization (ERS), suggesting a concomitant inhibition of task-irrelevant visual activity. In both Full and Free motor preparation, analysis of alpha power according to MRAA amplitude revealed two types of functional activation patterns: (1) a motor alpha pattern, with predominantly midparietal alpha ERS and large MRAA corresponding to lateralized motor activation/visual inhibition and (2) an attentional alpha pattern, with dominating right posterior alpha ERD and small MRAA reflecting visuospatial attention. The present results suggest that alpha oscillatory patterns do not resolve the selection mode of action, but rather distinguish separate functional strategies of motor preparation.