Avila University





Explanation of the rotating circles

The strong (and beautiful) rotation of the “wheels” occurs in relation to eye movements. On steady fixation the effect vanishes.

What to observe

  • Even when fixating steadily, illusory motion occurs on appearance/ disappearance
  • Illusion does not depend on colour
  • Rotation direction depends on the polarity of the luminance steps
  • Strength of illusion depends strongly on background luminance. Gregory & Heard (1983) were the first to describe that asymmetric luminance steps cause illusory movement.

 

 
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