Coupling between visual alpha oscillations and default mode activity.
Coupling between visual alpha oscillations and default mode activity.
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视觉α振荡与默认模式活动之间的耦合。
DOI：
10.1016/j.neuroimage.2012.11.058
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发表时间：
2013-03
期刊：
影响因子：
5.7
通讯作者：
Ding, Mingzhou
中科院分区：
文献类型：
--
作者：
Mo, Jue;Liu, Yuelu;Huang, Haiqing;Ding, Mingzhou
虽然，平均而言，阿尔法振荡（8至12赫兹）的幅度在任务相关的皮层在外部导向的注意力下降，其波动有显着的后果，与增加的阿尔法水平与视觉处理水平下降和较差的行为表现。功能性MRI信号表现出类似的波动。默认模式网络（DMN）在需要外部定向注意的认知任务中平均被停用。然而，DMN的暂时不充分失活通常伴随着刺激处理效率的降低，导致注意力丧失。这些观察似乎表明，视觉α功率和DMN活性可能呈正相关。在静息状态下，这种相关性在多大程度上得以保留尚不清楚。我们通过记录健康人参与者在两种静息状态下的同步EEG功能磁共振成像来解决这个问题：闭眼和睁眼。短时视觉α功率被提取为时间序列，然后与经典血流动力学反应函数（HRF）卷积，并与血氧水平依赖（BOLD）信号相关。结果发现，视觉α功率与DMN BOLD活性呈正相关，只有当眼睛是开放的;没有这种相关性存在时，眼睛是关闭的。从功能上讲，这可以解释为：（1）在睁眼条件下，强DMN活动与降低的视觉皮层兴奋性相关，这有助于阻止外部视觉输入干扰由DMN介导的内省心理处理，而弱DMN活动与增加的视觉皮层兴奋性相关，这有助于促进刺激处理，以及（2）在闭上眼睛的情况下，缺乏外部视觉输入使得这种选通机构不必要。
Although, on average, the magnitude of alpha oscillations (8 to 12 Hz) is decreased in task-relevant cortices during externally oriented attention, its fluctuations have significant consequences, with increased level of alpha associated with decreased level of visual processing and poorer behavioral performance. Functional MRI signals exhibit similar fluctuations. The default mode network (DMN) is on average deactivated in cognitive tasks requiring externally oriented attention. Momentarily insufficient deactivation of DMN, however, is often accompanied by decreased efficiency in stimulus processing, leading to attentional lapses. These observations appear to suggest that visual alpha power and DMN activity may be positively correlated. To what extent such correlation is preserved in the resting state is unclear. We addressed this problem by recording simultaneous EEG-fMRI from healthy human participants under two resting-state conditions: eyes-closed and eyes-open. Short-time visual alpha power was extracted as time series, which were then convolved with a canonical hemodynamic response function (HRF), and correlated with blood-oxygen-level-dependent (BOLD) signals. It was found that visual alpha power was positively correlated with DMN BOLD activity only when the eyes were open; no such correlation existed when the eyes were closed. Functionally, this could be interpreted as indicating that (1) under the eyes-open condition, strong DMN activity is associated with reduced visual cortical excitability, which serves to block external visual input from interfering with introspective mental processing mediated by DMN, while weak DMN activity is associated with increased visual cortical excitability, which helps to facilitate stimulus processing, and (2) under the eyes-closed condition, the lack of external visual input renders such a gating mechanism unnecessary.
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DOI：
10.1073/pnas.0504136102
发表时间：
2005-07-05
影响因子：
11.1
作者：
Fox, MD;Snyder, AZ;Raichle, ME
通讯作者：
Raichle, ME
影响因子：
2.9
作者：
Kuhnert, Marie-Therese;Geier, Christian;Lehnertz, Klaus
通讯作者：
Lehnertz, Klaus
影响因子：
2.5
作者：
Feige, B;Scheffler, K;Seifritz, E
通讯作者：
Seifritz, E
影响因子：
--
作者：
Berger, H
通讯作者：
Berger, H
影响因子：
5.7
作者：
Laufs, H;Kleinschmidt, A;Krakow, K
通讯作者：
Krakow, K