Experimental evidence that primate trichromacy is well suited for detecting primate social colour signals

Primate trichromatic colour vision has been hypothesized to be well tuned for detecting variation in facial coloration, which could be due to selection on either signal wavelengths or the sensitivities of the photoreceptors themselves. We provide one of the first empirical tests of this idea by asking whether, when compared with other visual systems, the information obtained through primate trichromatic vision confers an improved ability to detect the changes in facial colour that female macaque monkeys exhibit when they are proceptive. We presented pairs of digital images of faces of the same monkey to human observers and asked them to select the proceptive face. We tested images that simulated what would be seen by common catarrhine trichromatic vision, two additional trichromatic conditions and three dichromatic conditions. Performance under conditions of common catarrhine trichromacy, and trichromacy with narrowly separated LM cone pigments (common in female platyrrhines), was bette...已有假说指出，灵长类三色色觉的进化适配恰好可高效探测面部色彩差异，该适配性可能源于对信号波长，抑或是光感受器自身敏感度的正向选择。本研究针对这一假说开展了首批实证检验之一：通过对比其他视觉系统的探测表现，探究灵长类三色色觉所获取的视觉信息，是否能提升对雌性猕猴动情接受期所表现出的面部色彩变化的探测能力。我们向人类受试者展示同一猕猴面部的成对数字图像，并要求其从中选出处于动情接受期的面孔图像。我们测试了分别模拟狭鼻猴类（Catarrhini）常规三色视觉、另外两种三色视觉条件以及三种二色视觉条件下的图像。在常规狭鼻猴类三色视觉，以及带有窄分离长中波视锥色素（LM cone pigments，常见于雌性阔鼻猴类（Platyrrhini））的三色视觉条件下，受试者的表现更优……