Spinning dancer

The illusion, created in 2003 by Japanese web designer Nobuyuki Kayahara,[1][2] involves the apparent direction of motion of the figure.

[3] These results can be explained by a psychological study providing evidence for a viewing-from-above bias that influences observers' perceptions of the silhouette.

If observers report perceiving Kayahara's original silhouette as spinning clockwise more often than counterclockwise, there are two chief possibilities.

To tease these two possibilities apart, the researchers created their own versions of Kayahara's silhouette illusion by recreating the dancer and varying the camera elevations.

In popular psychology, the illusion has been incorrectly[6] identified as a personality test that supposedly reveals which hemisphere of the brain is dominant in the observer.

Under this wrong interpretation, it has been popularly called the "right brain–left brain test",[7] and was widely circulated on the Internet during late 2007 to early 2008.

[8] There are other optical illusions that depend on the same or a similar kind of visual ambiguity known as multistable, in that case bistable, perception.

One way of changing the direction perceived is to use averted vision and mentally look for an arm going behind instead of in front, then carefully move the eyes back.

Some may perceive a change in direction more easily by narrowing visual focus to a specific region of the image, such as the spinning foot or the shadow below the dancer and gradually looking upwards.

Slightly altered versions of the animation have been created with an additional visual cue to assist viewers who have difficulty seeing one rotation direction or the other.