Sunday, October 18, 2009

Mixed Messages

I have been reading two very interesting books. I recommend BOTH very much. They are both very easy to read and contain very interesting material that applies to a very wide range of psychological fields; especially cognitive psychology. (I could not think of a way to fit "very" in any more times than that without becoming less artful.)

Here is the information for both books (note that the hardcover of "Brain Rules" includes a DVD, but the less expensive soft-cover edition only supplies links to on-line videos; no DVD):
  1. Medina, J. (2008). Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School. Seattle, WA: Pear Press.
  2. Lilienfeld, S. O., Lynn, S. J., Ruscio, J., & Beyerstein, B. L. (2010). 50 Great Myths of Popular Psychology: Shattering Widespread Misconceptions about Human Behavior. Wiley-Blackwell.
My problem has to do with what is widely known as the "Ten Percent Myth" regarding human mental potential. I would be surprised if you hadn't heard about it already. It goes something like, "Humans only use ten percent of their brains. Imagine what we could do if we could harness the power of the remaining 90 percent?!"

When this myth comes up in class, I have always used the ladder analogy as a means of explaining why it is a misleading claim. Imagine you had a ladder with ten rungs on it. You place this ladder against your house to clean the gutters. You climb the ladder and start to work. As it turns out, you are only standing on one rung. Does that mean you are using only ten percent of the ladder? Can you see any benefit to more actively using all of the other rungs for gutter-cleaning? No, and no.

In the "50 myths" book mentioned above, the authors start with this very myth (which they refer to as the "most people only use ten percent of their brain power" myth). Unfortunately, it seems that in their discussion, they (actually, the section is written by Beyerstein, I believe, who passed away before the book was published) have slightly altered my sense of what the myth seems to suggest. Basically, they have interpreted the claim to mean that humans only use ten percent of their brain. This is quickly and clearly revealed to be a silly claim. If it were true that we really only used ten percent of our brains, then that makes 90 percent of our brains nothing more than gooey insulation! Taking an ice-pick (or whatever) to our brains would only cause us harm 10 percent of the time! Clearly not true. It seems like any little brain damage we incur results in hefty mental and/or behavioral fines!

While the Beyerstein approach to attacking the myth is a good one, it attacks a pretty limited interpretation of the claim. My interpretation of the claim is that we are never able to use more than 10-percent of our brain at any given time. Hence, this seems more closely aligned with the way the authors titled the claim themselves (i.e., "brain power" rather than just "brains").

My first argument against this variation of the claim is based on the "how long is a piece of string" analogy. In other words, how can we know what ten percent of the brain is when it comes to processing capacity?! Perhaps based on electrical activity? Imagine what your brain would be like if ALL neurons fired at the same time, and all the time?! Isn't that pretty much a grand description of a grand-daddy of grand mal epileptic seizures? Well zero-percent seems easy enough to measure (DEAD!), but since we can't really know what would really represent 100 percent FUNCTIONAL capacity, how can we know that we are using only 10 percent?! See the problem? It pretty much demonstrates that the claim is just grabbing some arbitrary percentage number out of someone's arbitrary butt-hole.

BUT NOW comes the mixed message.

In Medina's "Brain Rules" book, a portion of my world-view was bitch-slapped by the claim that, "In fact, the human brain cannot simultaneously activate more than 2 percent of its neurons at any one time. More than this, and the glucose supply becomes so quickly exhausted that you will faint." (page 20).


Ok, so does that mean that the ten percent myth is wrong because it is really the case that humans can only use TWO percent of their brain at any given time?!


NOW it makes me wonder if thinking (brain power) really couldn't be improved by somehow finding a way to artificially increase the blood flow and glucose supply to our skulls!

Would an increase in glucose supply capable of supporting a mere FOUR percent of my brain at any given time DOUBLE my thinking ability?!

I'm going to have to see about getting some clarification here. PLEASE, in the mean time, if anyone out there has some clarifying insight into this… let me know!