Once again, the internet steps out to challenge our senses, presenting an image that at first glance seems nothing out of the ordinary: a handful of strawberries on a small cake, placed on a plate. Everything looks fine, and the red of the strawberries makes them very attractive… but there's the catch. The image contains not a single red pixel. Where does a color that doesn't exist come from?
Games with mirrors, dots that sometimes appear and sometimes don't, evil dresses that cause chaos on the web… the team formed by eyes and brain is critical for human beings, yet it has accustomed us to unusual situations by observing things that aren't there, or that are actually completely different. We have already explored the reasons in a previous article: the brain has a certain preference for speed over accuracy, and it relies heavily on past experiences, memories, and expectations. That said… we offer you a cake with strawberries:
Why Do They Look Red?
Now, are they really strawberries? The physical characteristics are there, from their texture to their core. Yet, there is something wrong with them: they are not red. Yes, your brain reports from the information received that the strawberries look red, but its conclusion is incorrect. All you have to do to check it is download a copy of the image, open it in your favorite image editor and zoom in to the maximum. All you will find are several shades of green, gray and cyan. Even the faint yellow we see on the cake is not actually yellow. What is happening?
The Science of Color Constancy
The phenomenon is known as color constancy, and in relaxed terms, it is the color correction that our brain applies to things we see under different lighting conditions. It is not the same to see a strawberry in daylight than under fluorescent light, but we still see it red in both cases. In a way, what light sources do is contaminate the color, and our brain must compensate. The image was created by professor Akiyoshi Kitaoka from Ritsumeikan University, and his Twitter account is full of optical illusions. As expected, several people came out to dispute the "absence of red" in the image, but our journey ends here...
