Combining S-cone and luminance signals adversely affects discrimination of objects within backgrounds.
Combining S-cone and luminance signals adversely affects discrimination of objects within backgrounds.
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DOI：
10.1038/srep20504
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发表时间：
2016-02-09
影响因子：
4.6
通讯作者：
Martinovic J
中科院分区：
文献类型：
--
作者：
Jennings BJ;Tsattalios K;Chakravarthi R;Martinovic J
视觉系统处理嵌入在亮度和颜色都不同的复杂场景中的物体。在这样的场景中，颜色有助于从背景中分割对象，但它是否也影响已经由亮度信号定义的对象轮廓的感知组织，或者这些过程不受颜色存在的影响？我们研究了亮度和色度信号是否能持续处理嵌入在背景中的对象，通过改变对比度沿着的亮度尺寸和沿着两个锥对立的颜色方向。在第一个实验中的阈值对象/非对象歧视的Gaborised形状的存在和不存在的背景杂波。分量Gabor的对比度沿沿着单个颜色/亮度维度调制或同时沿沿着多个维度共调制。背景杂波仅提高了S-（L + M）和L + M组合信号的鉴别阈值。第二个实验通过证明该效应依赖于相对高的S-（L + M）对比度的存在来复制和扩展这一发现。这些结果表明，S-（L + M）信号损害空间视觉时，结合亮度。由于S-（L + M）信号的特征在于相对大的感受野，这可能是由于轮廓定义信息被求和的积分场的大小的增加。
The visual system processes objects embedded in complex scenes that vary in both luminance and colour. In such scenes, colour contributes to the segmentation of objects from backgrounds, but does it also affect perceptual organisation of object contours which are already defined by luminance signals, or are these processes unaffected by colour’s presence? We investigated if luminance and chromatic signals comparably sustain processing of objects embedded in backgrounds, by varying contrast along the luminance dimension and along the two cone-opponent colour directions. In the first experiment thresholds for object/non-object discrimination of Gaborised shapes were obtained in the presence and absence of background clutter. Contrast of the component Gabors was modulated along single colour/luminance dimensions or co-modulated along multiple dimensions simultaneously. Background clutter elevated discrimination thresholds only for combined S-(L + M) and L + M signals. The second experiment replicated and extended this finding by demonstrating that the effect was dependent on the presence of relatively high S-(L + M) contrast. These results indicate that S-(L + M) signals impair spatial vision when combined with luminance. Since S-(L + M) signals are characterised by relatively large receptive fields, this is likely to be due to an increase in the size of the integration field over which contour-defining information is summed.