Barberpole illusion

From Psychology Wiki

Community portal · Tasks to do · News · Help

Clinical · Educational · Ind&Org · Other fields · Professional · Transpersonal · World

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language
Personality | Philosophy | Research Methods | Social | Statistics

Cognitive Psychology: Attention · Learning · Memory · Motivation · Perception · Thinking

This barber pole contains a rotating cylindar driven by an electric motor. Rather than being percieved as rotating, the viewer will have the illusion of ascending or descending stripes (depending upon the direction of spin)

The barberpole illusion is a visual illusion that reveals biases in the processing of visual motion in the human brain. When a diagonally-striped pole is rotated around its longer axis, so that the stripes are moving in the direction of the pole's shorter axis, it nonetheless appears the stripes are moving in the direction of its longer axis. Motion perception is biased in the direction of the longer axis. If the pole is reduced to a circle, the bias is removed and the true motion of the contour is obvious.

The barberpole illusion. The stripes here appear to move downward along the pole's longer axis. However, the actual motion is a a rightward motion.

The motion is identical in both figures.

[edit] References