Help: Optical Illusion Insight

[Michael C]

So, is it possible that I am simultaneously seeing the actual purple dot plus the green burn-in which combines to be gray? In that case, I would be seeing a full circle of pseudo-green dots, which matches what I see when I look away, plus a full circle of purple dots (minus the removed dot), which matches what is actually there, and a single pseudo-green dot at the place where the purple dot was removed, which matches how the animation appears to me.

1) Is that what is happening?

That makes sense to me. To simplify matters, I tried stopping the animation and staring at one still frame. After a while, the purple dots almost completely disappeared. If I shifted my gaze slightly, I could see a ring of green dots and a ring of purple dots. By moving the direction of my stare back to the centre cross, I could make the two sets of dots coincide again: once again I could just see a set of very faint purple dots.

Also, if I stare directly at a single purple dot, I see the other purple dots disappear, but the dot I’m staring at remains. So I see the one purple dot, with a green dot that travels around the circle and replaces the purple dot when it gets to that position.

2) Why doesn’t the purple dot disappear like the rest?

I don't know. It doesn't work exactly like that for me: If I stare at a single purple dot it does get fainter. I do get the impression that it doesn't get quite as faint as the other dots, but the difference seems very slight. Is there a difference in colour perception between central and peripheral vision?

 

[robinson]

Like some of the other illusions mentioned, as well as some not mentioned, it shows us how much of what we see is created by our receptors, as well as the brain/mind that tries to make sense of it all.

 

[robinson]

Interesting.


It isn't just color receptors at play. I did a color swap and couldn't reproduce the effect. Yet gray scale creates a slight variation, at least to my sleep deprived brain right now.

 

[robinson]

Which doesn't explain why my animated gif failed to work. Hmm.... need more coffee.

 

[robinson]

How odd.