Okay so this is actually very cool. I see them face down and then when I find the one that isn’t face down they do indeed look face up. However what’s really neat is that I can repeat this. If I look back at it again they will be face down and then turn face up when I realize that one is face up. However, it’s not always the same one. Any one of these could be the “face up” one to me that causes the switch.

What if I told you you can switch it back the same way.

Bayesian Predictive Processing accounts of human cognition (in which it’s sometimes quipped that “perception is controlled hallucination”) offer an explanation for this type of optical illusion, also known as the “hollow face illusion”. We have a strong prior belief that plates should be concave (and faces should be convex) because that’s how they’re encountered most of the time in the world, so your brain generates this percept from its own inner beliefs. But then when you’re explicitly instructed to “see” it a different way, you manually override this effect and then you struggle to see them the original way.

Our brain first assumes that the light comes from above that’s why it assumes here that the light comes from top left. Then the plates look like upside down. As soon as it finds indications that the bowls are upright and the light comes from bottom right all the bowls look upright. The most left and most right bowls look kind of warped or not flat on the table assumed that they are upside down. The shadow in the middle also gives away that the bowls are not upside down.

I can’t see these as anything but face up?