人类早期视皮层对边缘所有权的选择性以及注意的调节作用

自然场景中的物体通常是互相遮挡的，识别这些物体的关键在于确定不同图像区域之间的边缘属于哪一个物体。然而，对于人类视皮层如何编码边缘所有权这个问题，我们知之甚少。在本研究中，我们设计了两个简单有效的视觉刺激作为实验材料。在这些刺激中，对情境信息的微小变动就可以导致边缘所有权的彻底改变。利用功能性核磁共振适应的方法，我们发现次级视皮层对边缘所有权显示了稳定可靠的选择性，而且这种选择性依赖于注意过程。本研究提供了第一个以人类被试为研究对象的实验证据，结果表明次级视皮层是对边缘所有权进行加工的关键区，而且该加工依赖于高级皮层区的调节反馈。

Border Ownership Selectivity in Human Early Visual Cortex and Its Modulation by Attention

Natural images are usually cluttered because objects occlude one another. A critical aspect of recognizing these visual objects is to identify the borders between image regions that belong to different objects. However, the neural coding of border ownership in human visual cortex is largely unknown. In this study, we designed two simple, but compelling stimuli in which a slight change of contextual information could induce a dramatic change of border ownership. Using fMRI adaptation, we found that border ownership selectivity in V2 was robust and reliable across subjects, and it was largely dependent on attention. Our study provide the first human evidence that V2 is a critical area for the processing of border ownership and that this processing depends on the modulation from higher-level cortical areas.