It’s the old myth heard time and again about how people use only ten percent of their brains. While for the people who repeat that myth, it’s probably true, the rest of us happily use all of our brains. That tired Ten-Percent claim pops up all the time. In 1998, national magazine ads for U.S. Satellite Broadcasting showed a drawing of a brain. Under it was the caption, “You only use 11 percent of its potential.” Well, they’re a little closer than the ten-percent figure, but still off by about 89 percent. In the beginning even I looked at that concept and thought of it as a plausible explanation for  a lot of things including magic, psychic abilities etc.

During the past few years and after various rounds of debates with friends, doctors and with engineers alike, I started to doubt it. One reason this myth has endured is that it has been adopted by psychics and other paranormal pushers to explain psychic powers. The biggest of these would be main stream media, there have been a few hundred movies showing psychics who have been seen saying “We only use ten percent of our minds. If scientists don’t know what we do with the other ninety percent, it must be used for psychic powers!” There have been even scores of books to those who are not exposed movies that time and again mention this tidbit saying that the rest is for the subconscious mind. Bollywood is not left far behind as well, Karthik calling Karthik was another movie which used this point.

The argument that psychic powers come from the unused majority of the brain is based on the argument from ignorance. In this Argument, lack of proof for a position (or simply lack of information) is used to try to support a particular claim. For example: Two people see a strange light in the sky. The first, a UFO believer, says, “See there! Can you explain that?” The skeptic replies that no, he can’t. The UFO believer is gleeful. “Ha! You don’t know what it is, so it must be aliens!” he says, arguing from ignorance. I am not a person who would say that UFO’s dont exist, neither do I say that they do. But I think there is not enough information to make a judgement on the same.

Getting back to the point, technology is working in my favor when it comes to proving this myth wrong.

1. Brain imaging research techniques such as PET scans (positron emission tomography) and fMRI (functional magnetic resonance imaging) clearly show that the vast majority of the brain does not lie fallow. Indeed, although certain minor functions may use only a small part of the brain at one time, any sufficiently complex set of activities or thought patterns will indeed use many parts of the brain. Just as people don’t use all of their muscle groups at one time, they also don’t use all of their brain at once. For any given activity, such as eating, watching television, making love, or reading, you may use a few specific parts of your brain. Over the course of a whole day, however, just about all of the brain is used at one time or another.
2. The myth presupposes an extreme localization of functions in the brain. If the “used” or “necessary” parts of the brain were scattered all around the organ, that would imply that much of the brain is in fact necessary. But the myth implies that the “used” part of the brain is a discrete area, and the “unused” part is like an appendix or tonsil, taking up space but essentially unnecessary. But if all those parts of the brain are unused, removal or damage to the “unused” part of the brain should be minor or unnoticed. Yet people who have suffered head trauma, a stroke, or other brain injury are frequently severely impaired. Have you ever heard a doctor say, “. . . But luckily when that bullet entered his skull, it only damaged the 90 percent of his brain he didn’t use”? Of course not.

I guess I am at this time convinced that the myth needs to be busted for all, and the fable of sort needs to end.

A lot more can be read on this topic with references here.