In this optical illusion, the outline of a dog is difficult to spot at first sight

One of the challenges that put our brains to the test is undoubtedly represented by optical illusions.

In fact, we often do not realize how the mental processes that underlie our visual perception can be "deceived", giving us back an absolutely false vision of reality.

Many of you may remember the visual experiment of the gorilla where a group of friends is playing in a room passing a ball from hand to hand and changing their positions, while the spectator is asked to always follow the position of the ball.

At the end of the experiment, it is revealed that none of the spectators had realized that a man dressed as a gorilla had passed right through the middle of the scene, before their very eyes!

This is because, by focusing on the ball, their brain had "excluded" all the other details of the scene, although certainly not negligible.

Here we propose another visual game, less elaborate but just as interesting.

 Looking at the image of this man, can you see ... a dog?

The illustration is very famous and has driven thousands of people crazy. Apparently, only 1% of the observers have managed to respond quickly. 

In the image, we see a man with a thick beard and closed eyes. Our brain immediately perceives the human figure, and somehow excludes any other possibility of interpretation. 

To be able to "interpret" something else, we must make a visual and cerebral effort and we must try to separate what we actually see from the processing that our brain brings back to us. Take a few minutes to try, and then look at the solution below.

Here is the solution ... did you arrive at this conclusion?