Sunday, February 2, 2014

Eye See What You Did There...

Eye see what you did there...
By: Joseph Vacca

What color would you say the picture below is? 

I would say blue, as you probably would as well. But what is to say that my blue isn't instead perceived as this:                                                       

How would you truly know that we are indeed seeing the same color? We have communicated that both are blue, but in reality I have learned to associate a different visual stimuli then you have with blue. You see color is a perception, a figment generated by our brains and given a description by our brains but that doesn't really exist. But before you go into “oh no here comes another philosophy class, I thought I finished that GE,” hear me out. Light is simply radiation or electromagnetic waves. Light itself does not have a color, just a frequency and a wavelength. It’s our eyes that pick up these distinct wavelengths and sends nerve signals to the brain that interprets these stimuli as colors. Some creatures, like us, can only see the visible spectrum of light (quite aptly named obviously) while other organisms such as bees can see in the ultraviolet spectrum to better find flowers. Even cooler is the Cichlid fish, who can see in infrared (IR). It is believed that this helps the fish hunt for food in shallow African rivers [1]. They also have patches of IR reflecting scales that are thought to attract mates [1].

[Look at those beautiful IR marks!!! Oh wait…]

But back to the eyes, the primary source of observation, the doorways to the soul, or at least the brain. As you may know, the eye has certain photoreceptors known as cones (for seeing clear, sharp central images) and rods (for peripheral or dim light settings). Your cones are divided into three subsets based on their properties. One type can perceive red light really well, another green, and the third blue. Light enters the eye and actually polarizes the cell, WAIT WHAT!?!?

That’s right, the rods and cones are actually excited and release MORE neurotransmitters when it’s dark. The addition of light actually causes the cells to hyperpolarize and not fire quite as frequently [2]. These change in signals are detected, which send electric pulses via the ganglion cells in the optic nerve to the primary visual cortex where everything is made sense of for you.

Try and wrap your mind around this one...

It’s these interpretations that allow you to make sense of the world you see, color included.
So I ask you again, what color do you see? Because my visual cortex is interpreting this type of blue as… as well… Hm I can’t seem to describe what blue looks like to me. It appears blue. There is no better way for me to describe what blue is. Try it yourself, go on I’ll wait.
Difficult isn’t it? This is known as the “explanatory gap” and can be best applied in a situation in which an individual tries to explain color to a person that has been blind since birth. That person has never seen color, nor could visualize what you see in your own personal consciousness. Now if you said something like, “well blue is a cold or calm color” well you are really only explaining a color with another sense, which is just as abstract. This is another reason why we can’t perceive someone else’s definition of blue. Tommy Edison (a man blind since birth) does a great job explaining what a confusing concept colors are to him on his youtube channel.
Lastly, I want you all to realize how easily your mind can be tricked into perceiving something differently then it is. Just google search “Illusion images” and you will come up with thousands of interesting images that test your perception by causing images to “move” or “grow” in size. But, I’m here to tell you that you are being fooled at this very moment, just by reading this text. Did you know your computer screen can only output three colors: red, blue, and green [3]?  So any color that you see on this screen is actually a combination of the three. Right now you’re probably saying “Joey, you must not have taken an art class here at school, or even played with paints as a little kid, because red blue and green can’t make up other colors like yellow.” To which I would say, “Yes I was a deprived child, but I do know how these computer screens work.”
After all I did this yesterday…

When you look at something like a yellow tennis ball your cones pick up a natural wavelength (around 570nm). Since you have three types of cones, and each detects at a different optimum color (red, green, or blue) some of your red and green cones are activated a little bit [4]. Your brain interprets these activations as the color yellow. Therefore it is easy for the computer screen to shine a little bit of green and a little bit of yellow, and your brain will say, “huh, it seems that I’m receiving a bit of both colors, so it must be that this object is yellow.” As long as the pixels on your screen are small enough, you can’t distinguish between the two colors, and your computer can create multi-colored images.

In conclusion, all we really have are our own perceptions. However, we can’t rely on our eyes to tell us the whole picture, and we can’t ask anyone else, because we never really fully experience what someone else sees. Until we develop a way to “see into each other’s minds” we are really all alone in our own thoughts and perceptions. But take solace in this fact. Because in the busy/social world in which we live in, it’s nice to know that we have privacy within our own minds.

1.       Bakker, T. M. 2012. Visual prey detection by near-infrared cues in a fish. The Science of Nature 99:1063-1066.
2.       Hubel, D. N.d. Eye, brain, and vision. Eye, Brain, and Vision. Web. 27 Jan. 2014. <>.
3.       Tyson, J. 2000. How LCDs work. Web. 1 Feb. 2014.
4.       Vsause. "This Is Not Yellow." YouTube. YouTube, 02 Sept. 2012. Web. 02 Feb. 2014. <>.

Video and Images links

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