School of Engineering, University of Tokyo, Tokyo, Japan.
Science. 2011 Nov 11;334(6057):829-31. doi: 10.1126/science.1203161.
Although recent psychophysical studies indicate that visual awareness and top-down attention are two distinct processes, it is not clear how they are neurally dissociated in the visual system. Using a two-by-two factorial functional magnetic resonance imaging design with binocular suppression, we found that the visibility or invisibility of a visual target led to only nonsignificant blood oxygenation level-dependent (BOLD) effects in the human primary visual cortex (V1). Directing attention toward and away from the target had much larger and robust effects across all study participants. The difference in the lower-level limit of BOLD activation between attention and awareness illustrates dissociated neural correlates of the two processes. Our results agree with previously reported V1 BOLD effects on attention, while they invite a reconsideration of the functional role of V1 in visual awareness.
尽管最近的心理物理学研究表明，视觉意识和自上而下的注意力是两个不同的过程，但它们在视觉系统中如何在神经上分离尚不清楚。使用具有双眼抑制的二乘二析因功能磁共振成像设计，我们发现，视觉目标的可见性或不可见性仅导致人类初级视觉皮层（V1）中血氧水平依赖（BOLD）效应无显著性差异。将注意力引导至目标和远离目标的方向会在所有研究参与者中产生更大且更稳健的影响。注意与意识之间的 BOLD 激活的较低水平限制之间的差异说明了这两个过程的神经相关性不同。我们的结果与之前关于注意力的 V1 BOLD 效应报告一致，同时也促使我们重新考虑 V1 在视觉意识中的功能作用。
