Sunday, November 11, 2012

Your Brain is a Liar

Posted by YouTube user: BBC

Your brain lies. Not all the time of course, but more often than most people would probably like to think. I talk about this a little on the last episode of the show and actually mentioned this particular demonstration, though I couldn't remember the name of it at the time. It's called the McGurk effect, and It was first described in 1976 in a paper by Harry McGurk and John MacDonald entitled "Hearing Lips and Seeing Voices". This illusion is a demonstration of one of the many ways in which your perception can be fooled, as your brain attempts to make sense of the visual and auditory stimuli it receives. It's a cool little effect, in which your brain actually changes the sound you hear based on the image it's being paired with. But the McGurk effect is just one of the many ways in which your brain can misrepresent the reality of the world around you, and it isn't even a particularly extreme example at that.

Image: Edward H Adelson
Take the colored squares illusion, which you've probably already seen in one form or another. This illusion is a more extreme example of your brain altering your perception to try and make sense of the reality in front of it. In this example, despite the fact that they look like completely different shades of grey, the A and B squares in the illustration are actually the same color. No, really. If you've never seen it before it's hard to believe. So I encourage you to throw the image into your image editor of choice and compare. It's awesome. Weird, but awesome. This illusion works primarily because of the shading, perspective, and various other perceived visual cues in the image. Your brain interprets these cues and determines the image to be a 3 dimensional one, adjusting the colors accordingly in the process. It's all more technical than that of course, and you can go HERE for a more detailed explanation of this particular illusion. But the important thing to understand about these illusions and others like them, is that they actually demonstrate what are otherwise undetectable flaws in our perception of the world around us.

But for most of us, the most poorly understood yet overly trusted function of the brain, has to be memory. Because as difficult as it may be to either accept for yourself, or to try and convince someone else that our perception of an event or phenomena could be the result of a failure to understand a fundamental flaw or limitation of our brains. The notion that even the most vivid memories in all our heads are not only flawed and contaminated, but in many cases outright false, seems all but impossible. But this too is true, as more and more studies have continued to show.

Memories exist in our brain as a combination of neural connections and chemicals, that I can't pretend to fully understand. But what matters, is that the brain doesn't actually function as hard drive, like most people imagine it to, and memories are not permanent fixtures in the brain as most people perceive them. Memories are malleable, highly susceptible to contamination, and become more distorted and degraded with time, outside influence, and recollection. Which are facts I think more people should be aware of, particularly given the importance still afforded to things like eye witness accounts as evidence in criminal trials. Or, somewhat more trivially, as justification for belief in religious, supernatural, or other unexplainable phenomena.

The point of this particular rambling, is not to impress you with my extensive academic understanding of brain science, particularly since I don't have any. Like most of the things I write about, attempting to better understand how the mind and our ability to perceive reality actually works, is just another in a long list of intellectual  topics, with which I am somewhat obsessed. My goal, was really just to make the point that I think it would do ourselves and the world in general an immeasurable amount of good, if everyone spent just the tiniest bit of their lives at least attempting to better understand how the engine that allows one to perceive and experience the world around us actually functions, rather than blindly following false assumptions. What can I say, I guess I'm just not a fan of blind faith. Who would have guessed?

Also, the brain is interesting, science is cool, and illusions are fun. If not a little nauseating. 

Seriously, don't stare at that thing down there for too long. Which is generally good advice to follow in most situations, BTW.

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