How many times have sci-fi shows inflicted this situation on us: Character X: Oh my god I can read minds! And move things with my brain! And start fires! And I'm suddenly becoming hella smart!Scientist character responsible for explaining things: Aha! Normally we only use 10 percent of our brains, but Character X is accessing the rest of his brain! Now s/he has super powers! Me, watching: ARRGG! Using even a pretty cursory knowledge of neuroscience, one thing is clear: We use our whole brain. We use different sections of it for motor control, for higher thought, for fight or flight reactions, and so on and so forth. When neuroscientists and their many colleagues testthebrain to see which parts are doing what, they're looking at the whole brain, not just 10 percent. So every time the meme pops up in even my favorite shows, I kind of go a little nuts. But I've always wondered: Where does this meme come from? Frankly, there is no clear understanding of the source. Maybe some people think we have a bunch of neurons that we're not using, or that we can only use 10-percent of our brain at a given moment. Or maybe they're looking at all that white matter in the pictures of brains, all that stuff that cushions the the gray matter, and wondering what that stuff does. But Discoverblogger and columnist Carl Zimmer has a piece this month that offers one possible explanation for the phenomenon:
In the mid-1800s researchers discovered cells in the brain that are not like neurons (the presumed active players of the brain) and called them glia, the Greek word for “glue.” Even though the brain contains about a trillion glia—10 times as many as there are neurons—the assumption was that those cells were nothing more than a passive support system. Today we know the name could not be more wrong.
So, roughly 150 years ago, scientists studying the brain wrote off 91 percent of our brain as mere glue for the more important neurons that do the actual thinking. We now understand that they were wrong, but this strikes me as the sort of fact that can seep into the general culture and then become very difficult to dislodge. The fact that psychics and TV shows through the years have propagated the myth surely can't help. Anyway, I highly recommend reading Zimmer's whole piece, as it is filled with his usual erudition. In short, he describes how scientists are making headway on solving the riddle of the glial cells. Among other tasks, they provide scaffolding for neurons, they insulate neurons, and they act like a kind of brain janitor, pruning dead or useless cells. Zimmer even cites Spanish neuroscientist Alfonso Araque who believes that certain glial cells assist with thinking and not just maintenance tasks for the lordly neurons. And now that this idea is, once again, scientifically dispensed with, a plea to the writers and producers of sci-fi shows and movies who care about actual science: No more of the 10-percent-of-our-brain myth, please. There's plenty of real mystery to support plots without using bogus ones.