Dependence of the retinal Ganglion cell's responses on local textures of natural scenes
Dependence of the retinal Ganglion cell's responses on local textures of natural scenes
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DOI：
10.1167/11.6.11
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发表时间：
2011-01-01
影响因子：
1.8
通讯作者：
Grzywacz, Norberto M.
中科院分区：
文献类型：
--
作者：
Cao, Xiwu;Merwine, David K.;Grzywacz, Norberto M.
自然图像对视网膜神经节细胞 (RGC) 反应有贡献的一个重要特性是感受野 (RF) 中心平均强度（对比度）的时间调制。然而，这些反应表现出很大的可变性。这种变化可能部分源于对 RF 中心自然图像的空间强度变化的响应，即它们的局部强度分布或局部视觉纹理。我们测试了从该假设得出的五个预测：首先，响应往往会随着自然图像局部视觉纹理的方差而增加。其次，自然图像中强度的倾斜分布导致其在相同平均强度的灰色背景上的起始和偏移响应不对称。第三，用自然图像的负片重复这个实验可以反转不对称性。第四，对图像执行强度直方图均衡化消除了不对称性。第五，RGC 的反应随着人造格子的空间对比度而增加。该假设通过了所有五项测试，这表明对自然图像的反应随着其视觉纹理的变化而增加。为了解释这种纹理敏感性，我们提出了一个模型，其中兔子的大多数 RGC 的 RF 具有多个非线性亚基。
An important property of natural images contributing to a retinal ganglion cell's (RGC) responses is the temporal modulation of mean intensity (contrast) in the receptive field (RF) center. However, these responses exhibit a significant amount of variability. This variability could arise in part from responses to the spatial intensity variation of the natural images in the RF center, i.e., their local intensity distribution or their local visual texture. We tested five predictions derived from this hypothesis: First, responses tend to increase with the variance of the local visual texture of natural images. Second, the skewed distribution of intensities in natural images leads to asymmetric responses to their onset and offset to and from a gray background of the same mean intensity. Third, repeating this experiment with the negative of natural images inverts the asymmetry. Fourth, performing an intensity histogram equalization of the images eliminates the asymmetry. Fifth, RGCs' responses increase with the spatial contrast of artificial plaids. The hypothesis passed all five tests, which indicate that responses to natural images increase with the variance of their visual texture. To account for this texture sensitivity, we propose a model in which the RFs of most RGCs of the rabbit have multiple nonlinear subunits.