Motion perception appears to be nothing out of the ordinary and when you see it, you will have no problem in saying that’s just a simple motion with lines going from top to bottom. However, that’s where things start getting tricky and your mighty brain turns out to be wrong about the direction in which the lines are moving. Do you want to put your brain to the test? 

If you want to challenge your brain to the ultimate test, look at the optical illusion above. Right off the bat, you will say that the lines are moving down, starting from the top right side and ending on the bottom left side. Has your brain been able to guess the motion of the lines correctly? 

Nope, your brain failed the challenge. The big revelation is that the lines are moving in an upward direction, starting from the bottom right side and ending on the top left side. Peculiar, yes, for the logic behind it, let’s find out, but first you should understand the basics of motion perception before the big reveal.

The Two Orders of Motion Perception 
Motion perception is a widely studied topic by psychologists and neurologists who found motion perception as a difficult subject to shed light on in terms of neural processing. Thus, making motion perception an even more interesting topic to explore and further delve in. After establishing countless studies and researching in-depth on motion perception, researchers were able to provide people with two clues, the first-order and second-order of motion perception.  

Defining First-order of Motion Perception 
Researchers credited Beta movement as being the first order of motion perception. They described beta movement as an object that appears to move, but in reality, is a sequence of motionless images. Sometimes referred to as apparent movement, you can see beta movement in the making of movies and TV shows. If you speed up the image, you can see the object of the same color as its background moving amongst each stimulus, which the scientists labeled pure motion or the first-order.

Defining Second-order of Motion Perception 
The second-order of motion perception differs from the first-order in the sense that it doesn’t focus on the brightness of the moving object, instead focuses on the contrast, flicker, and contrast. Researchers concluded that this is because your brain might have two separate pathways. Now, that you know about the two orders of motion perception, you’re ready for the big reveal.

Your Brain is Suffering from an Aperture Problem 
Neurons are a vital part of your visual field and their presence leads you to see objects differently than they appear. As a result, the direction the lines are moving creates an unclear and ambiguous problem because your visual system is unable to register it. Therefore, your neurons will only respond to what crosses their receptive field regardless of the direction and movement of the line, thus creating the aperture problem.

Motion Perception gives you a new insight on how your brain perceives moving lines and on how it’s unable able to register its true movement due to a simple aperture problem.  

© opticalspy 2014 

Hermann Ebbinghaus, a German psychologist, gave the scientific world a wonderful illusion, giving them a gateway to finding out how a human mind functions. The brilliant psychologist left a legacy behind, but before leaving, bestowed upon the world the Ebbinghaus Illusion. However, it wasn’t until 1901, when Edward B. Titchener, a British psychologist, popularized the illusion in his writings.

When Titchener discovered this magnificent illusion, he was taken aback at the tricks an illusion could play on the human mind. When word of this illusion spread around in the circles of scientists, they immediately saw it as an opportunity to delve deeper into the human mind to study the pathways of the brain, action and perception. Moreover, the discovery divided the scientific community as the debate regarding the brain having two separate pathways raged on.

The Scientific Storm Surrounding the Ebbinghaus Illusion 
When the illusion first came into being, scientists were in awe of the way the illusion managed to manipulate the brain. In order to understand how the illusion worked, they dedicated their time and effort into studying the workings of the illusion. This is when two separate point of views emerged, some scientists believed that the Ebbinghaus Illusion proved that the brain, indeed, had two separate pathways, one for perception and the other for action.

However, other scientists debated against that theory, refusing to acknowledge that the brain contained two individual pathways. Due to the difference in opinion, the theory to this day remains just a theory, yet to be proven. Putting the debate aside, the Ebbinghaus Illusion plays a vital role in the research of cognitive psychology. What was so special about the illusion that shook the world of scientists? The illusion was unlike any other they had seen before, it was truly unique, mystifying in how it manipulated the mind.

J.P. Guilford, an American psychologist, discovered the Barberpole Illusion outside a barbershop in 1929. He found it strange that stripes on the barber pole rotated on a vertical axis, but appeared to be moving in an upward direction. With the psychologist baffled and amazed, he wanted to explain the phenomenon.

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. 

© opticalspy 2014 

Have you ever seen a picture that depicts two entirely different images? Most probably, you have, but never bothered to learn the name of the phenomena that’s behind it, until now. The phenomenon that’s been intriguing generations of people is called multistable perception.

What is Multistable Perception? 
Multistable perception makes you doubt the image you see in the picture. It compels you to see the other image that your mind fails to perceive. So, you twist your head, squint your eyes, or move closer to the picture, until the other picture appears to you.

Now, you’re able to see a young woman and an old woman at the same time (“My Wife and Mother-in-Law”). There are many more pictures similar to that to leave you amazed and wondering how is this possible? Keep in mind that the world of illusions consists of endless possibilities with multistable illusion being one of the most prominent ones.

Multistable perception affects many functions besides the visual system, which include auditory, olfactory, and tactile. In order to produce a multistable illusion, the artist draws an ambiguous image, which the visual system is unable to recognize it in its entirety, thus giving birth to a perceptual phenomena.