The Ouchi illusion is an illusion named after its inventor, Japanese artist Hajime Ouchi. It works in a way where the central disk seems to float above the checkered background when moving the eyes around while viewing the figure. Scrolling the image horizontally or vertically provides a much stronger effect. In this version titled “Ouchi Quintuplets” from author Kentra Gilbert, the effect is amplified even stronger! If you’re asking yourself what causes this strange phenomenon, well the illusion is caused by random eye movements, which are independent in the horizontal and vertical directions. However, the two types of patterns in the figure nearly eliminate the effect of the eye movements parallel to each type of pattern. Consequently, the neurons stimulated by the disk convey the signal that the disk jitters due to the horizontal component of the eye movements, while the neurons stimulated by the background convey the signal that movements are due to the independent vertical component. Since the two regions jitter independently, the brain interprets the regions as corresponding to separate independent objects (Olveczky et al. 2003).
