University of Amsterdam, Department of Psychology,Weesperplein 4, Amsterdam, The
Psychol Sci. 2013 Jan 1;24(1):63-71. doi: 10.1177/0956797612449175. Epub 2012 Dec 10.
A striking example of the constructive nature of visual perception is how the human visual system completes contours of occluded objects. To date, it is unclear whether perceptual completion emerges during early stages of visual processing or whether higher-level mechanisms are necessary. To answer this question, we used transcranial magnetic stimulation to disrupt signaling in V1/V2 and in the lateral occipital (LO) area at different moments in time while participants performed a discrimination task involving a Kanizsa-type illusory figure. Results show that both V1/V2 and higher-level visual area LO are critically involved in perceptual completion. However, these areas seem to be involved in an inverse hierarchical fashion, in which the critical time window for V1/V2 follows that for LO. These results are in line with the growing evidence that feedback to V1/V2 contributes to perceptual completion.
一个引人注目的视觉感知的建设性本质的例子是人类视觉系统如何完成被遮挡物体的轮廓。迄今为止，尚不清楚感知完成是在视觉处理的早期阶段出现，还是需要更高层次的机制。为了回答这个问题，我们使用经颅磁刺激在参与者执行涉及 Kanizsa 错觉图形的辨别任务时，在不同时间点破坏 V1/V2 和外侧枕叶（LO）区域的信号。结果表明，V1/V2 和更高层次的视觉区域 LO 都在感知完成中起关键作用。然而，这些区域似乎以相反的层次方式参与，其中 V1/V2 的关键时间窗口紧随 LO。这些结果与越来越多的证据一致，即反馈到 V1/V2 有助于感知完成。
