Shape

More information: Otten, Pinto, Paffen, Seth & Kanai (in press). The Uniformity Illusion: Central stimuli can determine peripheral perception. Psychological Science

Six examples of the uniformity illusion with shape 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 two examples contain no fixation spot, the latter two are identical to the first two, but they do contain a fixation spot. The last two contain no fixation spot, and start with no central stimuli. Some people find that the illusion works better without a fixation spot, but you can try out which works best for yourself. 
  • Note, depending on your screen size and your distance to your screen, this illusion may even work without making the example full screen.
For more information, see the text below the examples.




More informationThe periphery is identical in all six examples, and consists of diamond, pentagons and hexagons. However, when the central stimuli consist of hexagons, the entire screen seems to be made up of hexagons, whereas if the central stimuli are circles, all stimuli seem to be circles. Interestingly, this illusion seems to still work fine, even when it is not viewed full screen, suggesting that shape information falls of more rapidly towards the periphery, than, for instance, luminance information. The first two example are with hexagons (Ex. 1) or circles as central stimuli (Ex. 2). Examples three and four are the same as the first two, but then with a flickering fixation spot. Examples five and six are the same as the first two, but now the central stimuli appear later. Now it can be seen that without central stimulation the peripheral stimuli seem to be edgy, undefined, shapes. However, once the central stimuli appear, the peripheral stimuli take on a clearer, but more illusory, shape.