Guess how many times this square changes color when moving back and forth

Psychologist Akiyoshi Kitaoka from Kyoto, Japan, posted a clip of optical illusions on Twitter, showing that moving objects can trick the human brain into their color.

This illusion consists of a small square running back and forth within a rectangle that is half pink and half blue, with mixed colors in the middle. To the viewer’s eye, the square is gray when moving in pink space, then appears to turn pink when in blue.

However, Kitaoka explains that even though the viewer sees the color change, in reality the color of the square remains the same as it moves from one area to another. The real color of the square is pink.

This is because the movement of the square and the colors it moves through trick our brains. The human brain makes assumptions about the color of a moving object based on the objects around it.

This phenomenon is known as the “chameleon effect”, it was explained in 2016 by two researchers Sang-Wook Hong and Min-Suk Kang in the journal Nature.

In their study titled “Color Motion Change,” Hong and Kang explain this optical illusion is caused by a principle called color perception – a color change from perception that occurs “when an object of color moving around a stationary object of the same color”.

The normalization process induced by subject movement may mediate changes in color perception, the authors write.

Therefore, human perception of color is not absolute. This can lead to controversial optical illusions, where people see different colors in an image – such as the “dress” that became a popular color theme in 2015. Image viewers will be divided into two trends, one is to see black and blue, the other is white and yellow.

This clip was first posted in 2018 but is gaining popularity on Twitter, leaving many viewers in awe.

Reference: Petapixel