Horridge Adrian
Biological Sciences, Australian National University, Canberra, ACT, Australia.
Eye Brain. 2014 Oct 31;6:9-17. doi: 10.2147/EB.S70522. eCollection 2014.
Bee eyes have photoreceptors for ultraviolet, green, and blue wavelengths that are excited by reflected white but not by black. With ultraviolet reflections excluded by the apparatus, bees can learn to distinguish between black, gray, and white, but theories of color vision are clearly of no help in explaining how they succeed. Human vision sidesteps the issue by constructing black and white in the brain. Bees have quite different and accessible mechanisms. As revealed by extensive tests of trained bees, bees learned two strong signals displayed on either target. The first input was the position and a measure of the green receptor modulation at the vertical edges of a black area, which included a measure of the angular width between the edges of black. They also learned the average position and total amount of blue reflected from white areas. These two inputs were sufficient to help decide which of two targets held the reward of sugar solution, but the bees cared nothing for the black or white as colors, or the direction of contrast at black/white edges. These findings provide a small step toward understanding, modeling, and implementing in silicon the anti-intuitive visual system of the honeybee, in feeding behavior.
蜜蜂的眼睛拥有对紫外线、绿色和蓝色波长敏感的光感受器，这些光感受器会被反射的白色光激发，而不会被黑色光激发。由于实验装置排除了紫外线反射，蜜蜂能够学会区分黑色、灰色和白色，但色觉理论显然无法解释它们是如何做到的。人类视觉通过在大脑中构建黑白图像来避开这个问题。蜜蜂有截然不同且易于理解的机制。通过对训练过的蜜蜂进行大量测试发现，蜜蜂学会了两个显示在任一目标上的强烈信号。第一个输入是黑色区域垂直边缘处绿色感受器调制的位置和测量值，其中包括黑色边缘之间角宽度的测量值。它们还学会了白色区域反射的蓝色光的平均位置和总量。这两个输入足以帮助判断两个目标中哪个含有糖水奖励，但蜜蜂对黑色或白色本身的颜色，或黑白边缘的对比度方向并不在意。这些发现朝着理解、建模并在硅片中实现蜜蜂在觅食行为中那违背直觉的视觉系统迈出了一小步。
