Dynamics of alpha control: preparatory suppression of posterior alpha oscillations by frontal modulators revealed with combined EEG and event-related optical signal.
Dynamics of alpha control: preparatory suppression of posterior alpha oscillations by frontal modulators revealed with combined EEG and event-related optical signal.
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DOI：
10.1162/jocn_a_00637
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发表时间：
2014-10
影响因子：
3.2
通讯作者：
Gratton G
中科院分区：
文献类型：
--
作者：
Mathewson KE;Beck DM;Ro T;Maclin EL;Low KA;Fabiani M;Gratton G
我们研究了促进外部刺激的有意识体验的大脑过程的动力学。先前我们提出，α（8-12赫兹）振荡，随着持续和定向注意力的波动，代表了对正在进行的感觉大脑活动的脉冲抑制。在这里，我们测试了视觉皮层抑制性α振荡是由额顶叶注意网络自上而下的信号调节的预测。当受试者执行视觉目标检测任务时，我们使用事件相关光信号（EROS）和同步记录的脑电图（EEG）测量额叶、顶叶和枕叶皮层的相参α振荡调制，EROS是一种提供高时空分辨率的神经元活动测量方法。脑电和EROS测量的靶前α振荡对随后未检测到的目标更大，支持α的抑制作用。使用EROS，我们将这些在头皮测量到的与意识相关的α振荡的脑相关性定位到楔叶和楔前叶。关键是，EROS α抑制与受试者的后验脑电图α功率相关。根据脑电α功率四分位数对EROS数据进行分类以研究α调节因子，结果表明，在抑制后侧α之前，背侧注意网络区域的活动增加，而扣窝-眼窝网络区域的活动减少。相互关联揭示了后验α调制之前这些预备网络内活动的时间动态。EEG和EROS的新组合提供了α振荡的来源和相关因素及其时间关系的定位，支持了我们的建议，即来自注意力网络的自上而下控制调节了后α和视觉刺激的意识。
We investigated the dynamics of brain processes facilitating conscious experience of external stimuli. Previously we proposed that alpha (8-12 Hz) oscillations, which fluctuate with both sustained and directed attention, represent a pulsed inhibition of ongoing sensory brain activity. Here we tested the prediction that inhibitory alpha oscillations in visual cortex are modulated by top-down signals from frontoparietal attention networks. We measured modulations in phase-coherent alpha oscillations from superficial frontal, parietal, and occipital cortices using the event-related optical signal (EROS), a measure of neuronal activity affording high spatiotemporal resolution, along with concurrently-recorded electroencephalogram (EEG), while subjects performed a visual target-detection task. The pre-target alpha oscillations measured with EEG and EROS from posterior areas were larger for subsequently undetected targets, supporting alpha's inhibitory role. Using EROS, we localized brain correlates of these awareness-related alpha oscillations measured at the scalp to the cuneus and precuneus. Crucially, EROS alpha suppression correlated with posterior EEG alpha power across subjects. Sorting the EROS data based on EEG alpha power quartiles to investigate alpha modulators revealed that suppression of posterior alpha was preceded by increased activity in regions of the dorsal attention network, and decreased activity in regions of the cingulo-opercular network. Cross-correlations revealed the temporal dynamics of activity within these preparatory networks prior to posterior alpha modulation. The novel combination of EEG and EROS afforded localization of the sources and correlates of alpha oscillations and their temporal relationships, supporting our proposal that top-down control from attention networks modulates both posterior alpha and awareness of visual stimuli.
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影响因子：
3.7
作者：
Ben-Simon E;Podlipsky I;Arieli A;Zhdanov A;Hendler T
通讯作者：
Hendler T
影响因子：
5.7
作者：
Gratton, G;Fabiani, M;Gratton, E
通讯作者：
Gratton, E
影响因子：
5.7
作者：
Hanslmayr, Simon;Aslan, Alp;Baeuml, Karl-Heinz
通讯作者：
Baeuml, Karl-Heinz
影响因子：
5.7
作者：
Gratton, G;Sarno, A;Fabiani, M
通讯作者：
Fabiani, M
影响因子：
3.7
作者：
GRATTON, G;CORBALLIS, PM
通讯作者：
CORBALLIS, PM