Transcranial alternating stimulation in a high gamma frequency range applied over V1 improves contrast perception but does not modulate spatial attention
Transcranial alternating stimulation in a high gamma frequency range applied over V1 improves contrast perception but does not modulate spatial attention
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DOI：
10.1016/j.brs.2011.08.008
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发表时间：
2012-10-01
影响因子：
7.7
通讯作者：
Paulus, Walter
中科院分区：
文献类型：
--
作者：
Laczo, Bence;Antal, Andrea;Paulus, Walter
空间视觉注意增强了其焦点内的信息加工。在一个参与的位置的视觉更快，更准确，更高的空间分辨率，并有一个增强的灵敏度对细微的变化。早期的假设认为，这些过程的神经元机制是基于不同神经元群之间的相互作用，通过皮层振荡在伽马范围内。目前研究的目的是利用一种叫做经颅交流电刺激（tACS）的新技术，从外部调节这些振荡。通过对20名健康受试者的高分辨率对比敏感度和对比辨别，研究了隐蔽空间注意焦点内外的影响。在初级视觉皮层（V1）上施加40、60和80 Hz的tAC刺激，在两种不同的条件下获得受试者的对比辨别阈值：在第一种条件下，我们将黑色光盘作为自动吸引受试者注意的外围线索，而在第二种条件下没有线索。我们发现对比敏感度的空间分布不受刺激的影响。另一方面，对比辨别阈值在60 Hz的tACS中显著降低，而40和80 Hz的刺激没有影响。这些结果表明，注意在受gamma范围tACS刺激影响的V1活动的对比辨别中起重要作用。(C) 2012爱思唯尔公司版权所有。
Spatial visual attention enhances information processing within its focus. Vision at an attended location is faster, more accurate, of higher spatial resolution, and has an enhanced sensitivity for fine changes. Earlier hypotheses suggest that the neuronal mechanisms of these processes are based on the interactions among different neuronal groups by means of cortical oscillations in the gamma range. The aim of the current study was to modulate these oscillations externally, using a new technique called transcranial alternating current stimulation (tACS). We investigated the effect of covert spatial attention within and outside its focus by probing contrast sensitivity and contrast discrimination at high resolution across the visual field of 20 healthy human subjects. While applying 40, 60, and 80 Hz tAC stimulation over the primary visual cortex (V1), subjects' contrast-discrimination thresholds were obtained using two different conditions: in the first condition we presented a black disc as a peripheral cue that automatically attracted the subject's attention, whereas there was no cue in the second condition. We found that the spatial profile of contrast sensitivity was not affected by the stimulation. Contrast-discrimination thresholds on the other hand decreased significantly during 60 Hz tACS, whereas there was no effect of 40 and 80 Hz stimulation. These results suggest that attention plays an important role in contrast discrimination based on V1 activities that are influences by gamma range tACS stimulation. (C) 2012 Elsevier Inc. All rights reserved.