There are many things that affect what we see. Optical illusions aren’t just fascinating; they teach us about how we visually perceive our surroundings. In our color perception series, we shared some of the factors that affect how we see color and the impact it has on manufacturing.
Today we’ll take a closer look at some of the ways our brains, eyes, and the environment can influence what we see… we’ll call it adult Trick or Treat!
Trick or Treat #1: Your Brain
Let’s start with the power of the human mind.
I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid! Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer inwaht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? Yaeh, and I awlyas thought slpeling was ipmorantt.
Could you read this paragraph?
Based on what it already knows, your brain is able to fill in lots of missing details to give you the most complete picture possible. If this is true, just imagine the tricks it can play on you!
Trick or Treat #2: Background Effects
Is this a coil or a circle?
The background checkerboard makes it hard to determine, but this picture is actually a series of circles, not one big spiral.
Here’s another. Parallel or not?
Blocking off each row with a sheet of paper will help you see that these horizontal lines are actually parallel.
Background effects are subtly at play all day long, and we don’t even notice. Contrasting colors and backgrounds have an effect on the way we perceive surrounding colors because we see in the context of the entire visual field.
Scientists believe this is a leftover effect of our primate heritage when humans wandered the savannah in search of food. Just as we see prairie animals doing today, we constantly stood and scanned the horizon for potential danger. After a few generations, this action became innate, and has stuck with us.
Since the human eye scans scenes horizontally, background color and shape strongly affect our perception, making background effects a key source of illusion.
Trick or Treat #3: After Images
If you’re like most people, you probably see both white and black dots… but how many black dots can you count? If your answer is zero, you’re absolutely right. There aren’t any black dots in this image, just white.
For this one, stare at the black +.
If you concentrate hard and don’t move your eyes, eventually all of the pink dots will disappear and be replaced by green.
For starters, our eyes get tired very easily. The cones in our eyes contain red, green and blue color sensitive photo-chemicals. When we stare at an object for longer than a few seconds, these chemicals start to deplete, and the cones begin sending incorrect information to our unsuspecting brains.
If everything looks a little weird after staring at that image, it’s okay. Your eyes will readjust in a few minutes. The best thing to do is close your eyes and let them rest, or look at a light, neutral gray shade until you notice colors starting to look normal again.
Trick or Treat #4: Color Memory
Are the A and B squares the same color?
They ARE the same color!
Why are we tricked? Our brains “learn” how objects should look, and we apply this knowledge to everything we see. In this image, we anticipate a shadow from the cylinder and our eyes actually adjust the colors!
Trick or Treat #5: Visual Phenomena
Dizzy yet? None of these images are actually moving.
Why are we tricked? Sometimes our brains just process incoming sensory information totally wrong. This is called visual phenomena.
So what’s the treat?
The good news is your eyes aren’t intentionally playing tricks on you. Your brain is managing vast amount of information and processing it the best it can. It’s really important to understand how we perceive color and objects in industries where color is crucial. Learn more about the impact of visual perception in manufacturing.
Are you color deficient? Take the online X-Rite Color challenge to find out!
For more fun optical illusions, visit http://www.michaelbach.de/ot/.