Colored Illusions

Colored Illusions

 

For this lesson I have chosen a Ted Talk video on perception and optical illusions. Dr. Beau Lotto has a PhD in Neuroscience and works at the Institute of Ophthalmology. He talks about color perception while using games and puzzles to test our ability to distinguish between reality and perception. He focuses on how our brain works, but more on how our projections and interactions with the world can perceive our reality, not to mention he has a really cool name, which caught my attention.

 

He opens his talk with a game of colored dots, asking the audience to choose which color dot from two different boards are really the same in color? He has them choose between orange, green or gray. The interesting part of the game is that with the boards side by side the colored dots all look like they are matching on either side, but when he pulls the colors orange and green off of the left board and sits them next to the similar color on the right board it is clear that the colors on the left board are much darker then on the right. The gray dot was the only one that was indeed the same color on both boards. This experiment uses the bottom-up process and clearly shows how the receptors in the eye detected the light in similar fashion while sending signals that these colors were reflecting as one and the same. In other words, the information taken from the environment signaled to the eye that the colors were equal in frequency creating the illusion of similarity, but in reality was a mislead.

 

Dr. Lotto explains that sensory information, the light that falls on the eye is meaningless and it is what we do with the information that structures our reality. He claims we see by learning to see, explaining that the brain evolves by finding patterns and relationships of information and using those relationship patterns with a behavioral meaning while interacting with the world.  He shows this very clearly by using letter strings to spell out sentences. An example he used is “Ca yu rea t is?” This experiment is using the top-down process by taking structured sentences from our past and applying them to connect the dots when pieces of the puzzle are missing.

 

The conclusion to his many experiments and games showed clearly how our brains can redefine normality by using color and past patterns. The hue upon which you set your sight on can determine what you are perceiving at that one moment in time and yet the truth can be far from what you perceive if the hue is changed and a different light is cast upon your vision. This trick of the eye uses movement, angles and relationships to influence how our brain deciphers information. The two applications of bottom-up and top-down can alter how the physiology of the brain processes its environment and therefore allows someone to experience a unique perspective unto themselves.

 

References:

Filmed JUL 2009 • Posted OCT 2009 • TEDGlobal2009

http://www.ted.com/talks/beau_lotto_optical_illusions_show_how_we_see.html

One thought on “Colored Illusions

  1. Dynette Lynn Nadeau

    If you liked Dr. Lotto’s colored dot game, you will love these:
    http://www.youtube.com/watch?v=lXcpWx5OSYo (Brain Games, 2014).
    This episode of Brain Games opens with a very cool illusion. The demonstration tricks your brain into seeing beautiful, vivid color in a tropical scene. The trick is you are really looking at a black and white image with no color at all! In your example, the misperception was caused by top down processing in which the brain uses previous knowledge to fill in the blanks. In this example, it is the actual physiology of the eye’s color receptors that transmit the wrong color signals to our brain. Before seeing the black and white image we’re shown some colors. Our receptors get tired of seeing those colors and basically decide to project the exact opposite colors to our brain. (Go to 2:21 in the video for a full explanation.) Interestingly, a variety of misperceptions can occur in spite of the information entering our sensory receptors being accurate.
    The sparkler illusion discussed by Goldstein in our Cognitive Psychology text provides yet another example of a misperception of the brain. Most of us enjoyed “drawing” circles and squiggles in the night sky with sparklers on the Fourth of July when we were children. Nowadays, children use glow sticks to enjoy the same effect but in a safer way. Did you ever get burned by a still hot sparkler? Ouch! As it turns out, the trail of light that children believe they are creating isn’t really there at all. ”The lighted trail is a creation of your mind, which retains a perception of the sparkler’s light for a fraction of a second” (Goldstein, 2008, p120). As you may recall, this phenomena is referred to as persistence of vision. So once again, our brains are perceiving something that is not really there. In this case, the brain places a past sensory perception into the present.
    The misperceptions above are temporary visual illusions. But what if these illusions persisted? How would that change your sense of reality? A glimpse into the world of neurological disorders provides us with a sense of just how fragile and, dare I say subjective, our sense of what’s real really is. Schizophrenia is a well-known example of a neurological disorder that immerses the sufferer in world of altered reality. Another, less well-known example is Alice in Wonderland Syndrome. I recently learned of it on a show called Broken Minds (2014). (OK, my secret is out, I’m hooked on psych shows!) There is a woman who begins seeing the things in her world around her morph into different sizes and shapes, much like the shift in reality Alice experiences on her strange trip down the rabbit hole. To get a sense of what she sees, this link will take you to a preview of the show http://www.youtube.com/watch?v=1TrsZJQuMs0 (Broken Minds, 2014). In the end, we find out that it is not a tumor or brain damage causing the problem but rather something a little more mundane: migranes! “Perception, attention, memory, imagery-basically every function of our brain depends on how the brain is representing information” (WC, 2013). And, as these demonstrations illustrate, these representations of the mind shape what it is that each of us believes to be REALITY!
    References:
    Brain Games (2014). “In Living Color” S3/Ep2. National Geographic Channel. Clip retrieved from http://www.youtube.com/watch?v=lXcpWx5OSYo
    Broken Minds (2014). “Down the Rabbit Hole” Discovery Health and Fitness Channel. Clip retrieved from http://www.youtube.com/watch?v=1TrsZJQuMs0
    Goldstein (2008). Cognitive Psychology (3rd ed.). Belmont, CA: Wadsworth.
    Pennsylvania State University World Campus (2013). PSYCH 256 Lesson 1: Cognitive Psychology: History and Research Methods. Retrieved from https://courses.worldcampus.psu.edu/sp14/psych256/003/content/02_lesson/03_page.html

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