Wednesday, July 8, 2009

Amazing Color Illusion - You Can't Deny It Even When You Know It is False

[Modified 10 July - Thanks Joel! See "PPS:"]
See the GREEN and BLUE swirls? Do you believe they are the EXACT same AQUA color?

I copied the area of GREEN swirl labelled as "1" and the area of BLUE swirl "2" and put expanded versions of each adjacent to each other so you can see they are really the EXACT same AQUA color.

OK, now that you know they are the same, look back at the swirls and you cannot make them not look GREEN and BLUE. Can you?

I think this is proof that, at least for color vision, we humans see things in a relative, contextual way rather than an absolute, isolated manner. A computer scanning the image pixel by pixel would have no trouble seeing the same color in both sets of swirls. However, we humans, even when we know for sure they are the same color, cannot dismiss the optical illusion.

Does this perhaps extend to other mental activities? Does it explain the contradictions in L-Mind and C-Mind thinking? L-Minds often willing to allow an otherwise normal unborn baby to be put to death at the whim of the mother while denying the justice system the legitimacy to use the death penalty on the most awful criminal? The C-Mind sometimes insisting that human life, once conceived, has an absolute right to live, while, at the same time, often supporting wars that kill large numbers of innocents as "collateral damage"?

Ira Glickstein

PS: Thanks to my son-in-law Avi for bringing this illusion to my attention on his Blog.

PPS: [Added 10 July] Thanks to Joel for his Comment with a link to an equally compelling optical illusion. I went to Joel's link and downloaded the image. Then I copied part of the "A" GRAY square and part of the "B" WHITE-looking square and pasted them in the upper left corner so you can see they are exactly the same shade of gray!


joel said...

The optical illusion you passed on is an interesting one illustrating one of the faults in our optical system. Perhaps I shouldn't say "fault," since although there are many such peculiarities of our visual interpretation (in fact books dedicated to such illustrations), they are generally speaking, a consequence of an evolved advantage of some kind. Line segments that are not there or lines that are straight but appear curved are examples of consequences of our interpolation and extrapolation ability. Color illusions are generally the result of the need for contrast against various backgrounds. I find it especially interesting that ancient Greek architects made "parallel" columns that were non-parallel in order to compensate for a "fault" in the human optical system.

When I started studying my concept of inborn L/C-minds, I hoped that I could find a simple non-political discriminator. It would be interesting to find an optical illusion that would do this. The trouble with most of them is that they are universal. Apparently, EVERYONE sees the color illusion you have presented. (On the other hand, ink blot interpretation is too variable.) What I hope for is something like the "chalice illusion" that is binary. You'll remember that in this illusion one sees either the silhouette of a chalice or a pair of profiles facing one another. It would be wonderful if L-minds saw one and C-minds saw the other at least at first glance. That would be proof of a wiring difference unconnected to education. -Joel

joel said...

P.S. An amazing example can be found at

in which two squares on a checker board appear to be different, but are in fact the same shade. This has to do with our ability to interpret two colors as being the same color even though they are lighted differently; for example, part of the foliage of a bush is in shade, but the other part is in shadow. We still interpret the greens to be matching thereby simplifying the problem of segmentation of the image.