We use almost all our brains

One sometimes hears that humans use only about 10% of our brains. Some have suggested that this means that if only we could learn how to harness our brains fully, we could be geniuses. Others have used it to argue, somewhat desperately, that this limited utilization is the reason for god’s ineffability, because in the unused portions lies the ability to understand how god works and what his plan for us is.

But that 10% figure turns out to be a myth.

The myth’s durability, [Barry Gordon at Johns Hopkins School of Medicine] says, stems from people’s conceptions about their own brains: they see their own shortcomings as evidence of the existence of untapped gray matter. This is a false assumption. What is correct, however, is that at certain moments in anyone’s life, such as when we are simply at rest and thinking, we may be using only 10 percent of our brains.

“It turns out though, that we use virtually every part of the brain, and that [most of] the brain is active almost all the time,” Gordon adds.

Although it’s true that at any given moment all of the brain’s regions are not concurrently firing, brain researchers using imaging technology have shown that, like the body’s muscles, most are continually active over a 24-hour period. “Evidence would show over a day you use 100 percent of the brain,” says John Henley, a neurologist at the Mayo Clinic in Rochester, Minn.

There is a lot we still don’t understand about the structure and function of the brain however.

Another mystery hidden within our crinkled cortices is that out of all the brain’s cells, only 10 percent are neurons; the other 90 percent are glial cells, which encapsulate and support neurons, but whose function remains largely unknown. Ultimately, it’s not that we use 10 percent of our brains, merely that we only understand about 10 percent of how it functions.

Brain science is going to be one of the most fascinating areas of scientific research in the next decade, ranging from learning more about deep issues like consciousness and free will, to becoming better able to treat the numerous ailments associated with brain malfunctions.


  1. jhendrix says

    As we learn more and it starts poking holes in their theology, Neuroscience is the next area that’s going to be attacked and distorted by the religious. Just like they’ve done with Evolution and Cosmology before it.

  2. says

    I thought is was well-known that it’s a myth? Consuming 20% of our energy intake, it’s a huge burden on the body. Not to mention it creates giant heads woman die because of, so it’s *so* obvious it’s a totally bogus assumption. Except when one doesn’t believe in evolution of course. O wait…

  3. says

    If we’re using “100%” of the brain, then that’d mean there’s some way that memories are encoded where all my nerves fire but I obviously don’t remember everything. I think that there’s some bigtime simplifying going on in his comments…

  4. Paul Hunter says

    Child birth until very recently, because of our large brains, was a leading cause of death for both parties. Humans are also born very nearly helpless and require years of care to even survive. If we only needed 10 % of our brains then evolution would have long ago selected for heads one tenth the size of the ones we actually have.

  5. ibbica says

    Um… no. Some thoughts:

    The neurons, glia, and blood vessels in your brain would die if they weren’t doing *something* all the time. Those that just sit around doing nothing, die (don’t worry, they’re removed fairly quickly; barring gross pathology, you don’t have a mass of dead cells in your brain!).

    The human brain actually does process all incoming sensory information. That information goes through a weeding-out process, and is not all necessarily stored somewhere permanent and readily accessible (i.e. salient). That doesn’t mean you’re “not using 100% of your brain”.

    If you want to talk about neurons being active as in “firing”… well, most actually do fire quite frequently – it’s just that they’re not necessarily synched with others in a manner that you’d want them to be, to remember something specific. If they’re not firing themselves, they’re being fired upon… and as a result of all these little bursts of activity individual neurons rewire themselves all the time, producing new connections and dissolving old ones.

    Some of your brain’s activity is dedicated to actively forgetting/erasing or suppressing recovery of previously-learned information. That’s not what I would call being ‘not used’ either.

    Let’s not forget either how much of the ‘use’ and ‘potential processing power’ of your brain is dedicated to just keeping you alive. It’s not all about memory storage.

    100% (or near enough as to make no difference) of the cells in your brain ARE “in use” at any given time. That it’s not necessarily being put to the specific use you want it to be is a different issue.

  6. kevinalexander says

    If I’m working on my car and can only use one wrench at a time, does that mean that I only use 10% of my socket set?

  7. Dunc says

    Ever heard of anybody suffering a traumatic brain injury, but suffering no effects, because it was to part of the 90% of his brain that he didn’t use? No, me neither…

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