Six examples of the Uniformity illusion with colour as an example.
- Open the video fullscreen.
- Keep your eyes fixated on the centre of the screen for a good amount of time (tens of seconds to minutes).
- The first three examples contain no fixation spot, the latter three are identical to the first three, but they do contain a fixation spot. Some people find that the illusion works better without a fixation spot, but you can try out which works best for yourself.
For more information, see the text below the examples.
More info: In all cases the colour in the periphery is identical. In the first example the central patch is more reddish, leading, after a while, to the perception of an entire red image. In the second image the central plane is more blue, leading to the image entirely being filled with blue. In the first two examples the boundary between central patch and peripheral patch is "soft", meaning that there is a small area where the colour slowly changes from the one into the other. In the third example there is a "hard" boundary, now there is no smooth transition of colours. In the latter case the illusion seems to work less well. We think that this occurs because now the prior of surface uniformity is less plausible to the brain.
Note that the illusion takes time to occur, and after occurrence may wane in and out of existence for different parts of the visual field.