McDermott Kyle C, Webster Michael A
Department of Psychology, University of Nevada, Reno, Reno, Nevada 89557, USA.
J Opt Soc Am A Opt Image Sci Vis. 2012 Feb 1;29(2):A108-17. doi: 10.1364/JOSAA.29.00A108.
The cone contrasts carrying different dimensions of color vision vary greatly in magnitude, yet the perceived contrast of color and luminance in the world appears similar. We examined how this perceptual balance is adjusted by adaptation to the contrast in images. Observers set the level of L vs. M and S vs. LM contrast in 1/f noise images to match the perceived strength of a fixed level of luminance contrast. The perceptual balance of color in the images was roughly consistent with the range of contrast characteristic of natural images. Relative perceived contrast could be strongly biased by brief prior exposure to images with lower or higher levels of chromatic contrast. Similar adaptation effects were found for luminance contrast in images of natural scenes. For both, observers reliably chose the contrast balance that appeared correct, and these choices were rapidly recalibrated by adaptation. This recalibration of the norm for contrast could reflect both changes in sensitivity and shifts in criterion. Our results are consistent with the possibility that color mechanisms adjust the range of their responses to match the range of signals in the environment, and that contrast adaptation plays an important role in these adjustments.
携带不同维度颜色视觉的视锥细胞对比度在大小上差异很大，但在现实世界中，颜色和亮度的感知对比度看起来却很相似。我们研究了如何通过对图像对比度的适应来调整这种感知平衡。观察者在1/f噪声图像中设置L与M以及S与LM的对比度水平，以匹配固定亮度对比度水平的感知强度。图像中颜色的感知平衡大致与自然图像对比度特征的范围一致。相对感知对比度可能会因之前短暂暴露于具有较低或较高色度对比度的图像而产生强烈偏差。在自然场景图像的亮度对比度方面也发现了类似的适应效果。对于这两者，观察者都能可靠地选择看起来正确的对比度平衡，并且这些选择会通过适应迅速重新校准。这种对比度规范的重新校准可能反映了敏感度的变化和标准的转变。我们的结果与以下可能性一致：颜色机制会调整其响应范围以匹配环境中的信号范围，并且对比度适应在这些调整中起着重要作用。
