He went on to say the perceived movement of the stripes was due to eye movements. With no concrete evidence to back up his theory, he admitted that this was just his own explanation of how the phenomenon was possible. In 1935, another renowned name in psychology, Hans Wallach stepped in to explain the phenomenon.
Explanation of Hans Wallach
Hans Wallach, a German-American psychologist, became interested in the Barberpole Illusion in 1935 and began to study the illusion closely, experimenting with it. He published his findings in an article, which was in German.
He wrote about how the illusion was created and the factors responsible for creating that illusion in the first place. His analysis explained that the terminal points along the diagonal lines of the pole interacted with the implied openings created by the edges of the barber’s pole.
For instance, diagonally striped barber’s pole is revolved around its vertical axis; the stripes will also appear to be moving in the same direction as its vertical axis. This is what makes the Barberpole Illusion so different from all the other illusions out there. If you still don’t get this illusion, maybe an example will help you better grasp what this illusion is all about.
Put Your Thinking Hat On
In the Barber Shop Illusion the lines are moving in an vertical fashion, right? When you see the illusion, you perceive that the lines in the barber pole must be moving vertically as well. Thus, to the human eye, the lines appear to be moving upwards as the pole moves around.
Another thing that influences this perception is that the illusion provides the brain with unclear information regarding the direction the lines are moving. Therefore, if the lines were moving horizontally in the barber’s pole, you would perceive it as such. It’s the same case if the lines were moving vertically. The reason for such a huge deception is that your visual system is only able to assess part of the information.
How the Barberpole Illusion Influences the Visual System?
Since, your visual system can only process part of the information that it sees, it’s not able to accurately define what is happening in this illusion. This is due to something called the aperture problem. Aperature problem occurs when no additional information is present as such is the case with this illusion. When you look at the illusion, you will see that the lines are moving down, right, and then vertical to the position of the barber pole. However, one can also perceive the lines to be going down or right.
Can you ever determine the true direction of the movement of the line? Unless you see the ends of the barber’s pole, you won’t be able to determine the true direction of the movement.