Content - Spiral After-Image

Spiral After-Image

Press the start button and then stare fixedly at close range at the red dot in the middle of the pattern.

After 20 seconds, a picture will suddenly appear in place of the pattern. You will be astonished at the way this stationary picture seems to move!

Try it again, but this time look at something else as soon as the pattern disappears.




What's going on?

We know from experience that an approaching object seems to get bigger and bigger, and that details are more and more recognisable.

In our brain, there are nerves that react to approaching objects and others that react to departing objects. If we look at a object that is standing still, the stimulus for both group of nerves are in balance. If you look for a while at the rotating spirals, one of the groups is constantly stimulated and fatigues.

After a short while of staring at the disc, a number of effects soon happen: a feeling of expansion and a feeling of contracting. The resonance of both movements leads us to breath in or out.

If you look at the ceiling or at a face, the fatigued group of nerves does not react anymore and you are convinced that the ceiling or the face is contracting and expanding.