The Coding of Color, Motion, and Their Conjunction in the Human Visual Cortex
The Coding of Color, Motion, and Their Conjunction in the Human Visual Cortex
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DOI：
10.1016/j.cub.2008.12.050
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发表时间：
2009-02-10
期刊：
影响因子：
9.2
通讯作者：
Bartels, Andreas
中科院分区：
文献类型：
--
作者：
Seymour, Kiley;Clifford, Colin W. G.;Bartels, Andreas
背景资料：颜色和运动是视觉大脑中分离处理的最好例子，这就引出了颜色-运动连接词是如何表现的问题。这个问题也被称为“绑定问题”。结果：人类志愿者观看的视觉显示器包含围绕中心旋转的彩色点。这些点可以是红色或绿色，顺时针或逆时针旋转，导致四种可能的刺激显示。这种刺激的叠加对提供了两个额外的显示，每个显示包含两种颜色和两个运动方向，但在它们的特征连接不同。我们应用多变量分类体素激活模式，而受试者看到这样的显示。我们的分析证实了方向运动信息在整个视觉皮层的存在，并提供了色调编码的证据，在所有的早期视觉领域，除了V5/MT+。在每个皮层区域内，颜色和运动的信息似乎被编码在不同的体素集合中。此外，我们的研究结果表明，在初级视觉cortex和beyond.Conclusions的特征连接的明确表示：结果表明，连接可以从空间激活模式已经在V1解码，表明在视觉处理的早期阶段的连接的明确编码。我们的研究结果提出了一种可能性，即被认为是结合问题的主要例子的解决方案早在V1就涉及神经机制。
Background: Color and motion serve as the prime examples of segregated processing in the visual brain, giving rise to the question how color-motion conjunctions are represented. This problem is also known as the "binding problem."Results: Human volunteers viewed visual displays containing colored dots rotating around the center. The dots could be red or green and rotate clockwise or counterclockwise, leading to four possible stimulus displays. Superimposed pairs of such stimuli provided two additional displays, each containing both colors and both directions of motion but differing in their feature conjunctions. We applied multivariate classifiers to voxel-activation patterns obtained while subjects viewed such displays. Our analyses confirm the presence of directional-motion information across visual cortex and provide evidence of hue coding in all early visual areas except V5/MT+. Within each cortical area, information on color and motion appeared to be coded in distinct sets of voxels. Furthermore, our results demonstrate the explicit representation of feature conjunctions in the primary visual cortex and beyond.Conclusions: The results show that conjunctions can be decoded from spatial activation patterns already in V1, indicating an explicit coding of conjunctions at early stages of visual processing. Our findings raise the possibility that the solution of what has been taken as the prime example of the binding problem engages neural mechanisms as early as V1.