Section on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA.
Annu Rev Neurosci. 2012;35:91-109. doi: 10.1146/annurev-neuro-062111-150356.
The primary visual cortex (V1) is the principal telencephalic recipient of visual input in humans and monkeys. It is unique among cortical areas in that its destruction results in chronic blindness. However, certain patients with V1 damage, though lacking visual awareness, exhibit visually guided behavior: blindsight. This phenomenon, together with evidence from electrophysiological, neuroimaging, and psychophysical experiments, has led to speculation that V1 activity has a special or direct role in generating conscious perception. To explore this issue, this article reviews experiments that have used two powerful paradigms--stimulus-induced perceptual suppression and chronic V1 ablation--each of which disrupts the ability to perceive salient visual stimuli. Focus is placed on recent neurophysiological, behavioral, and functional imaging studies from the nonhuman primate that shed light on V1's role in conscious awareness. In addition, anatomical pathways that relay visual information to the cortex during normal vision and in blindsight are reviewed. Although the critical role of V1 in primate vision follows naturally from its position as a bottleneck of visual signals, little evidence supports its direct contribution to visual awareness.
初级视皮层（V1）是人类和猴子接受视觉输入的主要端脑区域。它在皮质区域中是独一无二的，因为它的破坏会导致慢性失明。然而，某些 V1 损伤的患者尽管缺乏视觉意识，但表现出视觉引导的行为：盲视。这种现象，以及来自电生理学、神经影像学和心理物理学实验的证据，导致人们推测 V1 活动在产生意识知觉方面具有特殊或直接的作用。为了探讨这个问题，本文综述了使用两种强大范式——刺激诱导的知觉抑制和慢性 V1 消融——的实验，这两种范式都破坏了感知显著视觉刺激的能力。重点放在最近的非人类灵长类动物的神经生理学、行为和功能成像研究上，这些研究揭示了 V1 在意识知觉中的作用。此外，还回顾了在正常视觉和盲视期间将视觉信息传递到皮层的解剖通路。尽管 V1 在灵长类动物视觉中的关键作用是其自然的，因为它是视觉信号的瓶颈，但几乎没有证据支持它对视觉意识的直接贡献。
