TimB - 25 October 2012 10:18 PM
Write4U - 25 October 2012 09:51 PM
Occam. - 25 October 2012 03:25 PM
Geez, even a pragmatist in optical illusions. I kept staring at it, but couldn’t make the non-existent green dot appear. 
Occam
Was the picture moving? It is a moving gif. There is one empty space, which for me first turns a light violet ghost, and then to green dot circling slowly eating all the red dots like a little pacman, until there is only the circling green dot.
I think that the violet dots disappear, consecutively, one at a time and then reappear in a clockwise direction, giving the appearance of motion.
yes, of course. The point is that the empty space advances, but is perceived by the brain as a green dot moving. We fill in the space but with a different color! Is it an opposite or complimentary color or is the background color (in the empty space) that triggers a green response?
We can understand the dot shape, but green? Then as others have noticed, it seems that the entire brain process runs into trouble by producing all kinds of illusionary memes from just this very simple natural problem. I can make it a grey background with just a green dot circling. Complete erasure of the red dots….amazing.
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