Centre for Cognitive Neuroscience, University of Turku, Finland.
Neurosci Biobehav Rev. 2010 May;34(6):922-34. doi: 10.1016/j.neubiorev.2009.12.002. Epub 2009 Dec 11.
Electrophysiological recordings during visual tasks can shed light on the temporal dynamics of the subjective experience of seeing, visual awareness. This paper reviews studies on electrophysiological correlates of visual awareness operationalized as the difference between event-related potentials (ERPs) in response to stimuli that enter awareness and stimuli that do not. There are three candidates for such a correlate: enhancement of P1 around 100 ms, enhancement of early posterior negativity around 200 ms (visual awareness negativity, VAN), and enhancement of late positivity (LP) in the P3 time window around 400 ms. Review of studies using different manipulations of awareness suggests that VAN is the correlate of visual awareness that most consistently emerges across different manipulations of visual awareness. VAN emerges also relatively independent of manipulations of nonspatial attention, but seems to be dependent on spatial attention. The results suggest that visual awareness emerges about 200 ms after the onset of visual stimulation as a consequence of the activation of posterior occipito-temporal and parietal networks.
在视觉任务期间进行的电生理记录可以揭示主观视觉体验的时间动态，即视觉意识。本文综述了将与视觉意识相关联的电生理相关物操作化为对进入意识的刺激和未进入意识的刺激的事件相关电位 (ERP) 之间差异的研究。有三个候选物可以作为这种相关物：100ms 左右的 P1 增强、200ms 左右的早期后负性 (VAN) 增强以及 400ms 左右 P3 时间窗中的晚期正性 (LP) 增强。对使用不同意识操作的研究进行综述表明，VAN 是最一致地出现在不同意识操作中的视觉意识的相关物。VAN 也相对独立于非空间注意的操作而出现，但似乎依赖于空间注意。结果表明，视觉意识在视觉刺激开始后约 200 毫秒出现，这是后顶叶和顶叶网络激活的结果。
