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When I was a lowly graduate student—doing my PhD thesis on the brains of boas and pythons—I had the great fortune of having dinner with two Nobel prize winning brain scientists, David Hubel and Torsten Wiesel.
Not wanting to waste the opportunity, I asked the great men: where did the idea that we only use 10% of our brains come from, and is it true?
They smiled, shook their heads, and said that they weren’t sure where the idea originated. But both agreed that the 10% theory was a myth. Nature, they observed, does not waste resources that way because there is a name for species that are inefficient: fossils.
Our brains consume about 20% of the energy our bodies use, and to invest that much energy in a function that is only 10% efficient makes no evolutionary sense. If the 10% theory were true, we would either have much smaller brains or would be extinct.
Neuroscientist Barry Beyerstein pointed out that scans of metabolic activity in the brain reveal that all parts of the brain are active all of the time, and there is significant activity even during sleep (as anyone who has ever dreamt knows).
Although it is true that metabolic activity increases in local regions of the brain when these regions are active (for example, the nucleus accumbens increases its metabolic rate when we experience pleasure), research by Dr. Louis Sokoloff of the National Institutes of Health and others have shown that, overall, brain metabolism does not significantly increase, even during tasks that require intense mental concentration.
This means that even when we do exercise our brains more than the “normal” amount, we do not consume more energy, as would be the case if our brains only cranked along at 10% of their normal "speed."
That is not to say that we cannot get more out of our brains than we normally do. Psychologist William James, who likely originated the 10% myth during speeches to lay audiences in 1890, correctly pointed out that “people only meet a fraction of their full mental potential.”
Neuroscientist Lawrence Katz, in his book, Keep your brain alive, showed that we can improve our brain’s performance by doing the equivalent of mental weight lifting. Smelling new smells, driving alternate ways to work , and in general, encountering novel experiences that grow or strengthen new connections among neurons in our brains, all increase and preserve our mental faculties. Learning a new language, taking a class, meeting new people, and in general moving outside of our mental comfort zones, also strengthen our brains.
So, for those of you who hoped to tap into the “unused” part of your brain for ESP, telekinesis, or clairvoyance ----sorry. We can increase our brain’s abilities, but only for the mundane and normal, not the paranormal.
