Preferential responses to occluded objects in the human visual cortex
Preferential responses to occluded objects in the human visual cortex
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DOI：
10.1167/8.4.16
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发表时间：
2008-01-01
影响因子：
1.8
通讯作者：
Kersten, Daniel
中科院分区：
文献类型：
--
作者：
Hegde, Jay;Fang, Fang;Kersten, Daniel
当一个物体被部分遮挡时，我们是如何看到它的？这个有趣的过程的神经机制尚不清楚，部分原因是迄今为止对视觉物体感知的研究主要使用单个物体的刺激，如面部或常见的无生命物体，每一个都单独呈现。但在自然图像中，视觉对象通常被其他对象遮挡。计算研究表明，一个被遮挡的对象的感知需要的过程，是从一个未被遮挡的对象在平面视图的过程有很大的不同。我们研究了神经基板的闭塞对象的感知功能磁共振成像（fMRI）的人类受试者观看刺激，旨在引起或不引起闭塞对象的感知，但物理上非常相似。我们假设的区域，是选择性的被遮挡的物体，如果它们存在，将在两种条件下的差异活跃。我们发现两个区域，一个在腹侧的对象处理路径，另一个在背侧的对象处理路径，这是显着响应闭塞的对象。更重要的是，这两个区域的响应被遮挡的物体比未被遮挡的物体，这种增强的反应是不是由于低层次的差异，刺激，amodal完成本身，或行为任务。我们的结果识别了视觉皮质中相对于测试的其他刺激优先对遮挡物体做出反应的区域，并表明这些区域可能在遮挡物体的感知中发挥重要作用。
How do we see an object when it is partially obstructed from view? The neural mechanisms of this intriguing process are unclear, in part because studies of visual object perception heretofore have largely used stimuli of individual objects, such as faces or common inanimate objects, each presented alone. But in natural images, visual objects are typically occluded by other objects. Computational studies indicate that the perception of an occluded object requires processes that are substantially different from those for an unoccluded object in plain view. We studied the neural substrates of the perception of occluded objects using functional magnetic resonance imaging (fMRI) of human subjects viewing stimuli that were designed to elicit or not elicit the percept of an occluded object but were physically very similar. We hypothesized the regions that are selective for occluded objects, if they exist, will be differentially active during the two conditions. We found two regions, one in the ventral object processing pathway and another in the dorsal object processing pathway, that were significantly responsive to occluded objects. More importantly, both regions were significantly more responsive to occluded objects than to unoccluded objects, and this enhanced response was not attributable to low-level differences in the stimuli, amodal completion per se, or the behavioral task. Our results identify regions in the visual cortex that are preferentially responsive to occluded objects relative to other stimuli tested and indicate that these regions are likely to play an important role in the perception of occluded objects.