Sorry, but color me underwhelmed.
No doubt there is some instructive lesson to be drawn from this, about the neural or cognitive mechanisms of vision, but you do not tell us what it is, and neither does the video. (Something about edge detection, maybe?)
As it stands, it is an unspectacular and (to me, anyway) unsurprising illusion.
Aside from an explanation, one thing that might have made it a little more interesting would be if three pencils had been used to cover all of the shade transitions together. Would the rightmost shade look indistinguishable from the leftmost? If it did, the illusion would be noticeably more impressive. If it did not, it might produce an interesting visual paradox, with each shade apparently identical to the one next to it, but the end ones differing. But the video maker does not seem to have had the imagination to try it.
If it did not, it might produce an interesting visual paradox, with each shade apparently identical to the one next to it, but the end ones differing.
My google fu is bad today, but there's another similar illusion of a sheet of paper with a divider down the middle. It looks like the left side is a light gray and the right side is dark gray. Remove the divider and it either appears to be one solid color or gradual fade from one to the other. I can't remember which exactly.
Nigel, why don't you try it and let us know?
Now, the test colors are shades of blue, and the pencil is yellowish-orange, nearly its visual opposite. (Refer to the color wheel at http://www.tigercolor.com/color-lab/color-theory/images/color-wheel-300… for an example.) If the pencil had been green or purple, would the illusion fail?
Could this be the Cornsweet illusion (which sounds like what Bob is describing as well)? http://en.wikipedia.org/wiki/Cornsweet_illusion
why don't you try it and let us know
It appears to be a MOND autumn in the science glossies, as Science publishes a review on our favourite alternative physics theory and the status of MOND like extensions to general relativity.
He said: "I felt I'd test my hypothesis and I did that by getting my cat certified by a number of the most prominent lay hypnosis organisations in the United States. It was a frighteningly simple process.