Prediction of response speed by anticipatory high-frequency (gamma band) oscillations in the human brain
Prediction of response speed by anticipatory high-frequency (gamma band) oscillations in the human brain
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DOI：
10.1002/hbm.20056
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发表时间：
2005-01-01
影响因子：
4.8
通讯作者：
de Peralta, RG
中科院分区：
文献类型：
--
作者：
Andino, SLG;Michel, CM;de Peralta, RG
当受试者参与并事先知道如何做出反应时，对刺激的反应会更快。最近有人提出，出现这种情况是因为持续的神经元活动是在刺激之前的预期状态期间在空间和时间上结构化的。这种机制被认为介导自上而下的处理，促进与随后的感觉运动处理有关的分布式神经元群的早期分组和选择。为了验证这个模型，必须证明这种早期持续神经活动的某些特征与随后的感知决策或行为事件相关。我们在一项电生理学研究中研究了这一假设，12 名受试者执行了简单的视觉运动反应时间任务。对于每个受试者的每个单独试验，使用称为“ELECTRA”的线性分布逆解来估计每个脑体素的局部场电位（LFP）。通过对估计的 LFP 应用时频分解，计算警告提示和视觉刺激之间的时间段内不同频段的振荡能量。然后计算每次扫描的振荡能量和反应时间之间的非参数相关系数。刺激开始前额顶叶网络中的伽马带振荡活动与大量受试者的反应时间显着相关。这些结果为神经振荡作为调节运动动作速度的自上而下的注意力控制机制的作用提供了直接证据。 (C) 2004 Wiley-Liss, Inc.
Response to a stimulus is faster when a subject is attending and knows beforehand how to respond. It has been suggested recently that this occurs because ongoing neuronal activity is spatially and temporally structured during states of expectancy preceding a stimulus. This mechanism is believed to mediate top-down processing, facilitating the early grouping and selection of distributed neuronal ensembles implicated in ensuing sensory-motor processing. To validate this model, it must be shown that some features of this early ongoing neural activity are correlated with subsequent perceptual decisions or behavioral events. We investigated this hypothesis in an electrophysiologic study in 12 subjects carrying out a simple visuomotor reaction-time task. Local field potentials (LFP) at each brain voxel were estimated using a linear distributed inverse solution termed "ELECTRA" for each single trial of each subject. The energy of oscillations for different frequency bands was computed for the period between the warning cue and visual stimuli by applying a time-frequency decomposition to the estimated LFP. A nonparametric correlation coefficient was then calculated between energy of oscillations and reaction times for each single sweep. Gamma band oscillatory activity in a frontoparietal network before stimulus onset significantly correlated with reaction time for a significant amount of subjects. These results provide direct evidence for the role of neural oscillations as a top-down attentional control mechanism that mediates the speed of motor actions. (C) 2004 Wiley-Liss, Inc.