Functional dissociation of ongoing oscillatory brain states.
Functional dissociation of ongoing oscillatory brain states.
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DOI：
10.1371/journal.pone.0038090
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Rose M
中科院分区：
文献类型：
--
作者：
Salari N;Büchel C;Rose M
假设在输入刺激之前的神经组件的状态调制随后呈现的刺激的处理。这种状态的性质可以根据正在进行的振荡活动的频率而不同。特定频率范围的振荡大脑活动，如阿尔法(8-12赫兹)和伽马(30赫兹以上)频段的振荡，被假设在认知过程中发挥功能作用。因此，对这种刺激前活动的选择性调节可以阐明这些刺激前波动的功能作用。为此，我们采用了一种新的非侵入性脑机接口(BCI)策略，有选择地增加枕叶皮质的阿尔法或伽马波段活动，并在特定的大脑状态下自适应地呈现视觉刺激。在训练期间，振荡的大脑活动被在线估计并反馈给参与者，以实现对阿尔法或伽马波段振荡的有意调制。结果显示，志愿者有选择地增加阿尔法和伽马频率振荡，在频率范围和定位方面具有很高的特异性。在测试中，阿尔法或伽马波段的活动被在线分类，在定义的活动水平上，嵌入噪音的视觉对象被立即呈现出来，并必须由志愿者检测到。实验一考察了两种水平的刺激前伽马带活动对视觉加工的影响。在伽马频段活动增加的阶段，检测到的视觉对象明显更多。在实验II中，将这种效果与阿尔法波段活动水平的增加进行了比较。只有伽马频段活动增强，才能观察到视觉处理的改善。这两个实验都证明了刺激前伽马频段振荡对知觉加工的特定功能作用。我们认为，脑机接口方法允许选择性地调节振荡活动和直接评估行为后果，以测试不同振荡状态的大脑功能分离。
The state of a neural assembly preceding an incoming stimulus is assumed to modulate the processing of subsequently presented stimuli. The nature of this state can differ with respect to the frequency of ongoing oscillatory activity. Oscillatory brain activity of specific frequency range such as alpha (8–12 Hz) and gamma (above 30 Hz) band oscillations are hypothesized to play a functional role in cognitive processing. Therefore, a selective modulation of this prestimulus activity could clarify the functional role of these prestimulus fluctuations. For this purpose, we adopted a novel non-invasive brain-computer-interface (BCI) strategy to selectively increase alpha or gamma band activity in the occipital cortex combined with an adaptive presentation of visual stimuli within specific brain states. During training, oscillatory brain activity was estimated online and fed back to the participants to enable a deliberate modulation of alpha or gamma band oscillations. Results revealed that volunteers selectively increased alpha and gamma frequency oscillations with a high level of specificity regarding frequency range and localization. At testing, alpha or gamma band activity was classified online and at defined levels of activity, visual objects embedded in noise were presented instantly and had to be detected by the volunteer. In experiment I, the effect of two levels of prestimulus gamma band activity on visual processing was examined. During phases of increased gamma band activity significantly more visual objects were detected. In experiment II, the effect was compared against increased levels of alpha band activity. An improvement of visual processing was only observed for enhanced gamma band activity. Both experiments demonstrate the specific functional role of prestimulus gamma band oscillations for perceptual processing. We propose that the BCI method permits the selective modulation of oscillatory activity and the direct assessment of behavioral consequences to test for functional dissociations of different oscillatory brain states.
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影响因子：
5.3
作者：
Hesselmann, Guido;Kell, Christian A.;Kleinschmidt, Andreas
通讯作者：
Kleinschmidt, Andreas
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：
3
作者：
Hanslmayr, S;Sauseng, P;Klimesch, W
通讯作者：
Klimesch, W
DOI：
10.1073/pnas.1014528108
发表时间：
2011-06-28
影响因子：
11.1
作者：
Addante, Richard J.;Watrous, Andrew J.;Ranganath, Charan
通讯作者：
Ranganath, Charan
影响因子：
5.3
作者：
Becker, Robert;Reinacher, Matthias;Ritter, Petra
通讯作者：
Ritter, Petra