Lateralized Suppression of Alpha-Band EEG Activity As a Mechanism of Target Processing
Lateralized Suppression of Alpha-Band EEG Activity As a Mechanism of Target Processing
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DOI：
10.1523/jneurosci.0183-18.2018
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发表时间：
2019-01-30
影响因子：
5.3
通讯作者：
Luck, Steven J.
中科院分区：
文献类型：
--
作者：
Bacigalupo, Felix;Luck, Steven J.
自最早的EEG研究以来，α波段（8 - 12 Hz）EEG活动已与视觉注意力相关。最近使用空间线索范式的研究表明，阿尔法被抑制在半球对侧的一个待关注的位置，这表明阿尔法作为一种机制的准备注意。在这里，我们证明了alpha也在主动目标处理中发挥作用。在两个视觉搜索实验中记录了一组健康男性和女性受试者的EEG活动。除了α活动，我们还评估了N2pc事件相关电位成分，这是一种与视觉目标上的注意力集中密切相关的偏侧瞬态EEG反应。我们发现，视觉搜索目标触发了N2pc成分和对α波段活动的抑制，这在目标对侧的半球上最大（我们称之为"目标引发的侧化α抑制"或TELAS）。在实验1中，N2pc和TELAS都观察到的目标，在较低的视野，但不存在的上野目标。然而，这两个偏侧化效应有不同的时间进程，他们不同的拥挤在实验2中的操作。这些结果表明，偏侧α-带活动参与主动目标处理，并不仅仅是一个准备机制，也TELAS和N2PC反映了相关的，但可分离的视觉空间注意的神经机制。
Alpha-band (8 - 12 Hz) EEG activity has been linked to visual attention since the earliest EEG studies. More recent studies using spatial cuing paradigms have shown that alpha is suppressed over the hemisphere contralateral to a to-be-attended location, suggesting that alpha serves as a mechanism of preparatory attention. Here, we demonstrate that alpha also plays a role in active target processing. EEG activity was recorded from a group of healthy male and female human subjects in two visual search experiments. In addition to alpha activity, we also assessed the N2pc event-related potential component, a lateralized transient EEG response that has been tightly linked with the focusing of attention on visual targets. We found that the visual search targets triggered both an N2pc component and a suppression of alpha-band activity that was greatest over the hemisphere contralateral to the target (which we call "target-elicited lateralized alpha suppression" or TELAS). In Experiment 1, both N2pc and TELAS were observed for targets presented in the lower visual field but were absent for upper-field targets. However, these two lateralized effects had different time courses and they responded differently to manipulations of crowding in Experiment 2. These results indicate that lateralized alpha-band activity is involved in active target processing and is not solely a preparatory mechanism and also that TELAS and N2pc reflect a related but separable neural mechanism of visuospatial attention.