Get ready for a vanishing act, thanks to the efficiency of your brain.
The image below went viral this week after it was posted on Reddit with the promise that it would disappear after readers stared at it for a while.
Indeed, the pretty pastel colors soon start fading away, leaving only a white background. Go ahead and try it: stare right at the center of the image, focusing on one spot with a fixed gaze.
So what’s happening here?
It’s called the Troxler Effect, named after Ignaz Paul Vital Troxler, a Swiss physician who discovered the phenomenon more than 200 years ago. He noticed that when he made himself stare at a central point of an image, objects in his peripheral vision started to disappear within seconds.
The effect is particularly noticeable with low-contrast images, according to The Illusions Index, a database of illusion explanations maintained by the Centre for the Study of Perceptual Experience at the University of Glasgow.
So the soft pastel colors in the viral image disappear particularly fast. Your brain replaces — or fills in — the image depending on what background it’s on.
It happens as your body tries to make sense of the world. Normally, your eyes move all the time, even when you’re not aware of it, refreshing your field of vision and providing your brain with constant new stimuli to process.
But when you make yourself fix your gaze — suppressing those involuntary eye movements as much as possible — you experience "neural adaptation:" any constant light stimulus causes neurons to become desensitized, or get used to it, reducing the strength of their signal to the brain, The Illusions Index explains.
Your brain essentially stops paying attention to something that’s static — an efficient way to ignore input it considers unimportant. It's "information it has deemed, in a sense, too boring to process," according to Live Science.
“If we were to fixate perfectly, the entire world would fade from view,” researchers wrote about the phenomenon in Nature Reviews Neuroscience. Fortunately, those small involuntary eye movements keep everything exciting for your brain and in place in your field of vision. In this case, the moment you stop staring, the pretty pastel colors return.