Perception trumps knowledge: optical illusion

http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html

25 14 16 years ago

web.mit.edu

TheTarquin3• 16 years ago

What's even more interesting is how much of the image you can remove while still maintaining the illusion. Block out almost all the image except for squares A and B and just a VERY little bit of space around them. The two squares still look different colors.

The brain can mess with perception in pretty significant ways based on very little information.

J_McQuade• 16 years ago

I tried covering up bits with my hand, with bits of paper, and staring at it with varying intensities - I still didn't believe it until I loaded it up in Gimp and checked the colour values.

It seems our perception of colour could be like our perception of temperature - comparative, rather than 'quantitative' in any way. Anyone here know of any studies into this?

evanrmurphy• 16 years ago

I even got suspicious that the right image on the Proof page might have been doctored, but it does pass the Gimp test. :)

TheTarquin3• 16 years ago

An interesting idea. This would put it in the same class as a remarkably large number of emergent "senses" like our sense of distance or of weight, which are both effected by ancillary information.

joeyo• 16 years ago

The brain can mess with perception in pretty significant ways based on very little information.

Indeed. Which isn't too surprising since perception constructed by the brain. :) I think that the fact that you can't "will" yourself to see the colors how they "really are" suggests something the brain is taking some sort of computational shortcut to allow us to process light and shadows efficiently--one that is almost never wrong in the environment that we evolved in--that we can violate the assumptions of in the illusion.

TheTarquin3• 16 years ago

Which isn't too surprising since perception constructed by the brain. :)

Touché. I really should have said something like "the subconscious can mess..." or "the lizard brain can mess...".

dskhatri• 16 years ago

More illusions: http://web.mit.edu/persci/gaz/gaz-teaching/index.html

olegk• 16 years ago

This is sooo old. HN shouldn't have this crap on the front page.

nazgulnarsil• 16 years ago

WAY more dramatic for me: the blue and green spirals are the same color. http://blogs.discovermagazine.com/badastronomy/2009/06/24/th...

JoeAltmaier3• 16 years ago

Not really the same; the blue and green areas are mixed with other colors; its wellknown the eye sees finely mixed colors as different colors. The greyscale illusion uses quite large areas which is remarkable.

jamesbritt• 16 years ago

"the eye sees finely mixed colors as different colors"

These are hardly finely mixed. I'm 1.5 feet form my 24" monitor, looking at the thing, amazed at the illusion. I clearly see distinct stripes of color. I have to block out the bordering color with my fingers to perceive the real color.

bitwize• 16 years ago

Once I was told they were the same color it became one of those "CAN'T UNSEE" things.

Perception trumps knowledge: optical illusion

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