A simple account of cyclopean edge responses in macaque V2
A simple account of cyclopean edge responses in macaque V2
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DOI：
10.1523/jneurosci.5308-05.2006
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发表时间：
2006-07-19
影响因子：
5.3
通讯作者：
Cumming, Bruce G.
中科院分区：
文献类型：
--
作者：
Bredfeldt, Christine E.;Cumming, Bruce G.
最近的研究表明，V2 中的神经元选择性地响应仅由视差定义的图形边缘（独眼边缘）。这些响应是方向选择性的，通常更喜欢独眼轮廓和亮度轮廓的相似方向，这表明它们可能支持轮廓的线索不变表示。在这里，我们研究了纯局部视觉信息（在感受野附近）的处理在多大程度上可以解释这些结果，使用可能包含独眼边缘（由单个边缘分为两个区域的随机点的圆形斑块）的最贫乏的刺激。许多 V2 细胞对独眼边缘的反应比对均匀差异的反应更好，并且其中大多数细胞至少对独眼边缘的方向具有广泛的选择性。有两个特征反对线索不变的轮廓表示：（1）独眼边缘响应经常被分量差异的微小变化所废除； (2)尽管V2细胞经常对独眼边缘的两个标志（由边缘的哪一侧在前面定义）做出反应，但它们是在不同的边缘位置做出反应的。这些特性与简单的前馈方案一致，其中 V2 神经元接收来自具有不同视差选择性的多个 V1 亚基的输入。我们还发现了独眼边缘的首选方向和对比刺激之间的相关性，表明这种前馈布线不是随机的。这些特征表明，V2 对独眼边缘的反应可能有助于支持视觉通路中更高的线索不变轮廓表示。
It has been shown recently that neurons in V2 respond selectively to the edges of figures defined only by disparity (cyclopean edges). These responses are orientation selective, often preferring similar orientations for cyclopean and luminance contours, suggesting that they may support a cue-invariant representation of contours. Here, we investigate the extent to which processing of purely local visual information (in the vicinity of the receptive field) might explain such results, using the most impoverished stimulus possible containing a cyclopean edge (a circular patch of random dots divided into two regions by a single edge). Many V2 cells responded better to the cyclopean edge than to uniform disparities, and most of these were at least broadly selective for the orientation of the cyclopean edge. Two characteristics argue against a cue-invariant contour representation: (1) the cyclopean edge response was frequently abolished by small changes to the component disparities; and (2) although V2 cells frequently responded to both signs of a cyclopean edge (defined by which side of the edge is in front), they did so at different edge locations. These characteristics are consistent with a simple feedforward scheme in which V2 neurons receive inputs from several V1 subunits with different disparity selectivity. We also found a correlation between the preferred orientations for cyclopean edges and contrast stimuli, suggesting that this feedforward wiring is not random. These characteristics suggest that V2 responses to cyclopean edges may be useful in supporting a cue-invariant contour representation higher in the visual pathway.