Prestimulus oscillatory activity in the α band predicts visual discrimination ability
Prestimulus oscillatory activity in the α band predicts visual discrimination ability
复制标题
DOI：
10.1523/jneurosci.1853-07.2008
复制
发表时间：
2008-02-20
影响因子：
5.3
通讯作者：
Jensen, Ole
中科院分区：
文献类型：
--
作者：
Van Dijk, Hanneke;Schoffelen, Jan-Mathijs;Jensen, Ole
虽然人的脑电图和脑磁图（MEG）的静息和基线状态由α波段（类似于10 Hz）的振荡主导，但这些振荡的功能作用仍不清楚。在这项研究中，我们使用脑磁图来研究如何自发振荡在人类提出的视觉刺激调节视觉感知。受试者必须报告两个叠加的光盘之间的灰度级是否存在细微差异。然后，我们比较了正确（命中）与错误（错过）识别刺激的刺激前大脑活动。我们发现，视觉辨别能力随着刺激前α功率的增加而下降。鉴于反应时间并不随刺激前α功率而系统性变化，警惕性的变化不太可能解释辨别能力的变化。使用空间滤波器进行源重建使我们能够识别导致这种效应的大脑区域。调节视知觉的主要来源位于顶枕沟周围。我们认为，顶枕区的α功率反映了较高水平的地区，这有助于调节视觉流的增益施加的功能抑制。
Although the resting and baseline states of the human electroencephalogram and magnetoencephalogram (MEG) are dominated by oscillations in the alpha band (similar to 10 Hz), the functional role of these oscillations remains unclear. In this study we used MEG to investigate how spontaneous oscillations in humans presented before visual stimuli modulate visual perception. Subjects had to report if there was a subtle difference in gray levels between two superimposed presented discs. We then compared the prestimulus brain activity for correctly ( hits) versus incorrectly ( misses) identified stimuli. We found that visual discrimination ability decreased with an increase in prestimulus alpha power. Given that reaction times did not vary systematically with prestimulus alpha power changes in vigilance are not likely to explain the change in discrimination ability. Source reconstruction using spatial filters allowed us to identify the brain areas accounting for this effect. The dominant sources modulating visual perception were localized around the parieto-occipital sulcus. We suggest that the parieto-occipital alpha power reflects functional inhibition imposed by higher level areas, which serves to modulate the gain of the visual stream.