为意识视觉服务的神经底物的研究是认知神经科学尚未解决的问题之一。到目前为止,意识文学努力解开哪些大脑区域以及以什么顺序参与了视觉意识的产生,但是意识问题仍然不清楚。利用两个不同但互补的数据源(即,快速光学成像和脑电图),我们试图解开负责有意识视觉体验出现的神经动力学。我们的结果表明,有意识的视觉特征是纹状体外视觉区域的激活显着增加,特别是在枕骨外侧复合体(LOC),而且,更有趣的是,这种活动发生在ERP组件的时间窗口中,通常被认为代表视觉意识的电生理特征,即,视觉意识的否定。此外,格兰杰因果关系分析,为了进一步调查被调查区域发生的活动流,揭示了与意识感知有关的神经过程主要起源于LOC,随后传播到视觉和运动区域。总的来说,本研究的结果似乎主张LOC在意识视觉中的早期贡献,因此表明它可以代表视觉感知的可靠神经关联。相反,条纹视觉区域,仅在刺激处理的后期阶段显示与意识相关的活动,可能是意识出现后神经事件级联的一部分。
The study of the neural substrates that serve conscious vision is one of the unsolved questions of cognitive neuroscience. So far, consciousness literature has endeavoured to disentangle which brain areas and in what order are involved in giving rise to visual awareness, but the problem of consciousness still remains unsolved. Availing of two different but complementary sources of data (i.e., Fast Optical Imaging and EEG), we sought to unravel the neural dynamics responsible for the emergence of a conscious visual experience. Our results revealed that conscious vision is characterized by a significant increase of activation in extra-striate visual areas, specifically in the Lateral Occipital Complex (LOC), and that, more interestingly, such activity occurred in the temporal window of the ERP component commonly thought to represent the electrophysiological signature of visual awareness, i.e., the Visual Awareness Negativity (VAN). Furthermore, Granger causality analysis, performed to further investigate the flow of activity occurring in the investigated areas, unveiled that neural processes relating to conscious perception mainly originated in LOC and subsequently spread towards visual and motor areas. In general, the results of the present study seem to advocate for an early contribution of LOC in conscious vision, thus suggesting that it could represent a reliable neural correlate of visual awareness. Conversely, striate visual areas, showing awareness-related activity only in later stages of stimulus processing, could be part of the cascade of neural events following awareness emergence.