Dear Cecil et al.,
I regret to inform you that, based on what I was taught in medical school 4 years ago, humans do use only 10% of our brain. This fact is not due to some lack of total enlightenment or accumulation of mental debris but rather due to human brains only being composed of 10% neurons. That’s right, our all-important organ is primarily composed of “glue” (literally, glial cells which compose the vast majority of our brain cells is from the Latin for “glue”). Despite the fact most of our brain cells are just scaffolding, the majority of brain mass and function is from the 10% neurons. Much like our desktop PC’s where most of the plastic is related to architecture and other functions like cooling, power routing, etc. the neuroglia support the workhorse neurons so that the are unencumbered in any other way to carry out their extremely specialized purpose.
That may be so, but it still doesn’t apply to the traditional use of the cliche. I’ve always assumed it to mean “we only use 10% our potential thought processing, creative, analytic brain capacity.” Your 10% is still basically all of what we can work with.
Are you saying that if you somehow magically removed all of the glial cells, that we’d continue to function just fine? Somehow, I doubt that. It seems much more likely that we use 100% of our brain cells, 10% for thinking and 90% for supporting the thinking ones.
Besides, the glial cells are being used. They perform essential maintenance and nutritional functions without which those fancy-schmancy neurons wouldn’t keep firing for long.
Anyway, according to an article in the April 2004 Scientific American (The Other Half of the Brain, by R. Douglas Fields) glial cells are not just there to support the neurons, but have now been shown to actually transmit electro-chemical impulses much as neurons do (though more slowly I think), and thus almost certainly play a direct role in the brain’s information processing.
Quite apart from that, any neuroscientist will tell you that the claim that we only use 10% (or some other small proportion) of our brains is a completely baseless canard. We use it all (even dumb people). Cecil should have been a lot more ruthless in dismissing this one.
No cite, but one debunking of this myth that I have heard involved the easy-to-digest snippet that 30% of our brain is devoted to processing vision.
Does this sound even remotely true to anybody here? It sounds plausible to me, but then again maybe I’m only using a small fraction of my brain.
I could see that.
I was not implying that we only use 10% of our brains b/c only that much is neurons; what I was saying is that 10% of our brains are neurons, and “classically” those are the “thinking” parts of the brain while the remaining 90% perform vital support/maintanence/infection-fighting tasks. I will cop to my ignorance of newer trends in Neuroscience as I have not read/studied said material since 2001, though it would NOT surprise me in the least that neuroglia are much more than mere drones in the veritable beehive of the human brain as our brains are so complex as to even astound the great Cecil “hisself”.
I see!
If you are saying that the brain is made up of 10 percent of neurons out of the total neurons in the body, then you mean to say that we use 10 percent of the total NEURONS, and 5 or whatever percentage of the brain capacity. See? (This need not imply that some neurons are never used. Perhaps it is the WAY how we use them, i.e. ‘think’, that defines the word “capacity”.)
No, he’s not saying that at all.
He’s saying that we use all the neurons in the brain, which comprise 10% of our total number of brain cells, the other 90% being glial cells and the like.
It still has nothing to do with the moronic notion that we only use 10% of our brain, no matter how it is phrased.
Too many colitas, dude. 
if we just use 10% of our brains … what do we do with the other half???
just wondering …
cheers
Al
ps: 
I don’t know if it is 30%, but most (if not all) of the occipital lobe (at the rear of the brain) is dedicated to processing vision. In further support of your snippet, subset portions of the occipital lobe are dedicated to specific visual tasks: some perceive movement, some identify and interpret straight line elements within the visual field, some process shapes, some color, and so on. I also recall that atrophy of specific portions of the occipital lobe is found if, for example, one eye is blind, relative to the portions linked to the sighted eye.
So, if we are killing brain cells, for example with alcohol and drugs, there is only a 10% chance of knocking out one of the important ones?
(Not to imply that the glial cells are not important, any network relies on it’s matrix as much as the individual componants. I’m just inferring that if we knock down some phone lines, the phones still function but don’t communicate properly)
And if so, which group of cells is most likely to either reproduce or transfer function?
Would different methods of brain damage affect the likelyhood of which types of cells are damaged (eg. concussion, asphixiation, chemical damage like pollution or drugs)?
I’ve heard, anecdotally, that part of the origin of the ‘only 10%’ myth has to do with early brain researchers studying people with injuries to limited parts of the brain. The idea is, the researchers could figure out what a particular part of the brain does by finding someone who lost that part of the brain and seeing what they couldn’t do.
Anyway, they discovered that many people would eventually recover some of the missing functions, leading to the erroneous conclusion by some that there was plenty of extra capacity in the brain just sitting around waiting for an injury to occur.
I could believe that, at any one time, an average of 10% of the brain is in use; if all the neurons fired all the time, there would be no room for the complexity of processing that results in thought and perception.
It’s a bit like saying that my computer’s memory is only ever used to about 50% of it’s maximum capacity, because it’s never more than about half full of binary '1’s - the zeroes are just as important; the neurons in your brain that are not firing at any particular moment are important in that they are part of the whole firing pattern.
There are certain parts of the brain that are more sensitive than others to particular toxins/mechanisms of injury. For example, ethyl alcohol (“the social lubricant”) is more toxic to the neurons in the cerebellum (the “little brain” on the caudodorsal part of the brain that deals w/refinement and coordination of movt) which is why the roadside test of standing on one foot w/eyes closed and touching your nose w/an outstretched hand is fairly sensitive for intoxication as opposed to other tasks such as reciting alphabet backwards, etc. However, ethanol depresses all neuron function to some degree so that increasing amounts have a generalized depressant effect on the entire nervous system (ie black-out).
As for concussion and the like, some aspects of brain function are loosely focused in certain areas of the brain (the “homonculus” and the like) such that damage to those areas will interfere w/those functions more so than others. For example, the oft-cited Phineas Gage sustained a devastating lesion to his supraorbital medial frontal lobe as a result of a penetrating trauma. He survived the wound but was found to have profound lapses in executive functioning (ie from calm, mild-mannered engineer to raucous hellion) after the blow. The frontal lobe is well known to be involved in personality and higher-level functioning. I’m sure some of the more well-read people out there may be able to add more and/or dispute this generalized point…
I always thought the 10% figure came from the Yogi Berra quote “90% of it is half mental”.
You do the math.
The awful truth is that we are NOT operating at 10% of capacity. We are actually at 100%! This here right now is the best it’s going to get! It’s NOT going to get any better.
Folks, we are DOOMED!