A brain-hurting illusion

September 5, 2015 • 7:15 am

Here’s a good way to wake up, though it’s not as efficacious as caffeine. Matthew loves optical illusions, and sent me this one, which was the first thing I saw when I woke up. And indeed, my brain still hurts.

Click the arrow to start:


27 thoughts on “A brain-hurting illusion

  1. Do you see white crosses on a black background, or vice versa, or both – in which case when do they change over?

    1. The “illusion” is that at the start, middle and end point of the animation, it looks like a pattern of white and black crosses. And they don’t change position, it’s just that in the first half, the white crosses stay intact, and in the second half, the black ones do. And the background just is … well … an implication. I guess the weird effect comes from keeping the eye on the white cross, even when it’s black crosses rotating.

  2. Well, that’s forever burned on the back of my retina! At first I didn’t understand it because I was moving my eyes over the whole thing trying to figure it out. If you just sit there and look at the whole picture, you’ll see the crosses alter from black to white & the background change from black to white.

    Stupid brain. Get it together!

    1. Focus on a point. It doesn’t change color. Looking at the forest as a whole, then the backgrounds appear to reverse.

  3. I am now..’experienced’, as Jimi Hendrix would say.
    It is mainly a brain bender kind of animation, but do people here see that the crosses are at times enclosed by faint grey lines forming squares, and faint white lines forming circles? I bet those are optical illusions.

      1. The faint lines might be left from the person who created/drew the piece. It seems to be just flipping the background from white to black and spinning the crosses in opposite direction.

        1. But those ‘pixels’ could be pixels in our minds & not on the screen. If we download it, we can get a frame by frame of the gif and see.

    1. … do people here see that the crosses are at times enclosed by faint grey lines forming squares, and faint white lines forming circles?

      Those squares and circles you’re hallucinating might be “purple haze” flashbacks.

  4. You can get a better handle on what’s happening by following a particular patch. Pick a single square and imagine it’s an actual tile. Watch it simply move in an arc…and then get split in two. and get joined up with another square that’s just been similarly split.

    The illusion is that the rotation is entirely unremarkable, but the splitting isn’t something consistent with the rotation — at least, not if we assume that the pieces doing the rotation are simple and solid.

    I bet somebody particularly clever might be able to make a real-world physical device that mimicked this behavior. It would not be easy. And the field is effectively infinite, so such an implementation would be limited to a short-duration run or you’d need some way of transporting tiles from one edge to the opposite side.

    Very well done, regardless.


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