The role of gamma and alpha oscillations for blocking out distraction.
The role of gamma and alpha oscillations for blocking out distraction.
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DOI：
10.4161/cib.22702
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发表时间：
2013-01-01
影响因子：
--
通讯作者：
Jensen O
中科院分区：
文献类型：
--
作者：
Bonnefond M;Jensen O
虽然阿尔法活动(10赫兹)是迄今为止人脑产生的最强信号，但几十年来，它一直被认为是反映休息或空闲的信号。然而，最近的研究清楚地表明，阿尔法活动在认知加工中起着关键作用。伽马振荡(>；30赫兹)及其对认知的作用也一直是深入研究的主题。虽然伽马活动被认为反映了功能处理，但阿尔法振荡现在被认为反映了功能抑制，以抑制分散注意力的信息的处理。在我们最近的脑磁图研究中，我们发现后方α振荡的功率和相位都是自上而下的调制，以防止工作记忆中并入可预测的干扰因素。我们在这里进一步讨论这些结果。此外，我们还表明，干扰的处理与要记住的项目的处理是明显不同的。前者诱发较弱的伽马能量，而诱发较高的α活动。诱发的阿尔法活动越高，分心抑制的效率就越高，这也取决于分心前的阿尔法功率和相位调整。总之，这些结果强调了α活性的保护作用及其显著的灵活性。这种抑制分心信息的能力在我们复杂的环境中至关重要，注意力障碍患者遇到的困难就证明了这一点。
Although alpha activity (10 Hz) is by far the strongest signal produced by the human brain, it has for decades been considered to reflect rest or idling. However, recent studies have clearly demonstrated that alpha activity plays a pivotal role for cognitive processing. Gamma oscillations (> 30 Hz) and their role for cognition have also been the subject of intensive research. While gamma activity is thought to reflect functional processing, alpha oscillations are now thought to reflect functional inhibition in order to suppress the processing of distracting information. In our recent magnetoencephalography study we found that both power and phase of posterior alpha oscillations are top-down modulated in order to prevent the incorporation of predictable distracters in working memory. We further discuss these results here. We additionally show that the processing of the distracters is clearly distinguishable from the processing of the items to be remembered. The former induced a weaker gamma power and evoked a higher alpha activity. The higher the evoked alpha activity, the better the efficiency of distracter suppression which also depends on the pre-distracter alpha power and phase adjustment. Altogether, these results emphasize the protecting role of alpha activity and its remarkable flexibility. This ability to inhibit distracter information is crucial in our complex environment, as illustrated by the difficulties encountered by patients suffering from attentional disorders.