Selective modulation of interhemispheric functional connectivity by HD-tACS shapes perception.
Selective modulation of interhemispheric functional connectivity by HD-tACS shapes perception.
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DOI：
10.1371/journal.pbio.1002031
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发表时间：
2014-12
期刊：
影响因子：
9.8
通讯作者：
Engel AK
中科院分区：
文献类型：
--
作者：
Helfrich RF;Knepper H;Nolte G;Strüber D;Rach S;Herrmann CS;Schneider TR;Engel AK
这项经颅刺激研究表明，大脑两个半球之间同步神经元活动的选择性调节可以影响意识知觉。皮层区域之间的振荡神经元同步被认为构成了一种灵活的机制来协调人类大脑皮层中的信息流。然而，目前尚不清楚同步的神经元活动是否仅仅是一种附带现象，或者它是否与信息的选择性选通有关。在这里，我们结合了40赫兹的双侧高密度经颅交流电刺激(HD-TAC)和同步脑电(EEG)记录，以研究在选择性夹带振荡伽马频段特征时的即时电生理效应。我们发现大脑半球之间的功能连接是以一种可预测的、特定于阶段的方式进行调制的：同相刺激增强同步性，反相刺激削弱功能耦合。在一个模糊的动作任务中发现了这些连接性变化的知觉关联，这有力地支持了长程神经元耦合的功能相关性。此外，我们的结果显示，随着伽马带特征的夹带，振荡的阿尔法功率有所下降。这一发现为顶枕皮质中α和伽马振荡的拮抗作用提供了因果证据，并证实了所观察到的伽马频段调制本质上是生理学的。我们的结果表明，在几个时空尺度上同步的皮层网络活动对于有意识的感知和认知是必不可少的。大脑活动具有深刻的节律性，在非常宽的频率范围内(<；0.1赫兹到>；600赫兹)呈现出看似随机的波动。最近，越来越明显的是，这些大脑节律不仅是大脑工作的一般标志，而且实际上反映了一种高度灵活的信息编码和传输机制。特别是，有人提出，大脑皮层不同区域之间的振荡同步是建立任务相关网络的基础。在这里，我们调查了伽马频段同步(∼40 Hz)是否因果地参与了交替视觉标记的两个大脑半球之间的整合，以形成一致的运动知觉。我们使用了经颅交流电刺激(TACS)，这是一种新的非侵入性脑刺激技术，允许特定频率的皮质区域夹带。在一项TACS-脑电的联合研究中，我们选择性地上调和下调大脑半球间的连贯性，导致表观运动知觉的定向偏差：大脑半球间连通性的增加维持了水平运动知觉，而连通性的降低则强化了垂直运动知觉。因此，我们的数据表明，大脑半球间伽马频段相干性的水平直接影响到瞬时运动感知。根据这些结果，我们得出结论，同步的神经元活动对意识知觉和认知是必不可少的。
This transcranial stimulation study shows that selective modulation of synchronized neuronal activity between the hemispheres of the brain can affect conscious perception. Oscillatory neuronal synchronization between cortical areas has been suggested to constitute a flexible mechanism to coordinate information flow in the human cerebral cortex. However, it remains unclear whether synchronized neuronal activity merely represents an epiphenomenon or whether it is causally involved in the selective gating of information. Here, we combined bilateral high-density transcranial alternating current stimulation (HD-tACS) at 40 Hz with simultaneous electroencephalographic (EEG) recordings to study immediate electrophysiological effects during the selective entrainment of oscillatory gamma-band signatures. We found that interhemispheric functional connectivity was modulated in a predictable, phase-specific way: In-phase stimulation enhanced synchronization, anti-phase stimulation impaired functional coupling. Perceptual correlates of these connectivity changes were found in an ambiguous motion task, which strongly support the functional relevance of long-range neuronal coupling. Additionally, our results revealed a decrease in oscillatory alpha power in response to the entrainment of gamma band signatures. This finding provides causal evidence for the antagonistic role of alpha and gamma oscillations in the parieto-occipital cortex and confirms that the observed gamma band modulations were physiological in nature. Our results demonstrate that synchronized cortical network activity across several spatiotemporal scales is essential for conscious perception and cognition. Brain activity is profoundly rhythmic and exhibits seemingly random fluctuations across a very broad frequency range (<0.1 Hz to >600 Hz). Recently, it has become evident that these brain rhythms are not just a generic sign of the brain-at-work, but actually reflect a highly flexible mechanism for information encoding and transfer. In particular, it has been suggested that oscillatory synchronization between different areas of the cortex underlies the establishment of task-relevant networks. Here, we investigated whether gamma-band synchronization (∼40 Hz) is causally involved in the integration between the two brain hemispheres of alternating visual tokens into a coherent motion percept. We utilized transcranial alternating current stimulation (tACS), a novel non-invasive brain stimulation technique, which allows frequency-specific entrainment of cortical areas. In a combined tACS-electroencephalography study, we selectively up- and down-regulated interhemispheric coherence, resulting in a directed bias in apparent motion perception: Increased interhemispheric connectivity sustained the horizontal motion percept, while decreased connectivity reinforced the vertical percept. Thus, our data suggest that the level of interhemispheric gamma-band coherence directly influenced the instantaneous motion percept. From these results, we conclude that synchronized neuronal activity is essential for conscious perception and cognition.
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影响因子：
16.2
作者：
Bosman CA;Schoffelen JM;Brunet N;Oostenveld R;Bastos AM;Womelsdorf T;Rubehn B;Stieglitz T;De Weerd P;Fries P
通讯作者：
Fries P
DOI：
10.1073/pnas.94.23.12699
发表时间：
1997-11-11
影响因子：
11.1
作者：
Fries, P;Roelfsema, PR;Singer, W
通讯作者：
Singer, W
影响因子：
5.3
作者：
Busch, Niko A.;Dubois, Julien;VanRullen, Rufin
通讯作者：
VanRullen, Rufin
影响因子：
9.2
作者：
Brittain, John-Stuart;Probert-Smith, Penny;Aziz, Tipu Z.;Brown, Peter
通讯作者：
Brown, Peter
DOI：
10.1073/pnas.1315529111
发表时间：
2014-01-14
影响因子：
11.1
作者：
Goni, Joaquin;van den Heuvel, Martijn P.;Sporns, Olaf
通讯作者：
Sporns, Olaf