Colour cues proved to be more informative for dogs than brightness
Anna A. Kasparson1,Jason Badridze2 andVadim V. Maximov1?
It has long been known that dogs’ eyes are physically equipped to perceive colors, thus, they are not colorblind. But dogs are believed to see only shades of yellow, blue, and gray. That’s because their eyes have only two types of color-sensitive “cone” cells as compared to three in the human eye.
Abstract
The results of early studies on colour vision in dogs led to the conclusion that chromatic cues are unimportant for dogs during their normal activities. Nevertheless, the canine retina possesses two cone types which provide at least the potential for colour vision.
Recently, experiments controlling for the brightness information in visual stimuli demonstrated that dogs have the ability to perform chromatic discrimination. Here, we show that for eight previously untrained dogs colour proved to be more informative than brightness when choosing between visual stimuli differing both in brightness and chromaticity. Although brightness could have been used by the dogs in our experiments (unlike previous studies), it was not. Our results demonstrate that under natural photopic lighting conditions colour information may be predominant even for animals that possess only two spectral types of cone photoreceptors.
http://rspb.royalsocietypublishing.org/
Proceeding of the Royal Society B