Whenever I venture out of the Ivory Tower to deliver public lectures about the brain, by far the most likely question I can expect as the talk winds up is, “Do we really only use 10 percent of our brains?” The look of disappointment that usually follows when I say it isn’t so strongly suggests that the 10-percent myth is one of those hopeful shibboleths that refuses to die simply because it would be so darn nice if it were true.
Why would a neuroscientist immediately doubt that 90 percent of the average brain lies perpetually fallow? First of all, it is obvious that the brain, like all our other organs, has been shaped by natural selection. Brain tissue is metabolically expensive both to grow and to run, and it strains credulity to think that evolution would have permitted squandering of resources on a scale necessary to build and maintain such a massively underutilized organ. Moreover, doubts are fueled by ample evidence from clinical neurology. Losing far less than 90 percent of the brain to accident or disease has catastrophic consequences. What is more, observing the effects of head injury reveals that there does not seem to be any area of the brain that can be destroyed by strokes, head trauma, or other manner, without leaving the patient with some kind of functional deficit. Likewise, electrical stimulation of points in the brain during neurosurgery has failed so far to uncover any dormant areas where no percept, emotion or movement is elicited by applying these tiny currents.
Do we really use only 10 percent of our brains?
Barry L. Beyerstein of the Brain Behavior Laboratory at Simon Fraser University in Vancouver explains.
March 8, 2004
Scientific American
https://www.scientificamerican.com/article/do-we-really-use-only-10/
Whenever I venture out of the Ivory Tower to deliver public lectures about the brain, by far the most likely question I can expect as the talk winds up is, “Do we really only use 10 percent of our brains?” The look of disappointment that usually follows when I say it isn’t so strongly suggests that the 10-percent myth is one of those hopeful shibboleths that refuses to die simply because it would be so darn nice if it were true. I’m sure none of us would turn down a mighty hike in brainpower if it were attainable, and a seemingly never-ending stream of crackpot schemes and devices continues to be advanced by hucksters who trade on the myth. Always on the lookout for a “feel-good” story, the media have also played their part in keeping the myth alive. A study of self-improvement products by a panel of the prestigious National Research Council, Enhancing Human Performance, surveyed an assortment of the less far-fetched offerings of the “brain booster” genre and came to the conclusion that (alas!) there is no reliable substitute for practice and hard work when it comes to getting ahead in life. This unwelcome news has done little, however, to dissuade millions who are comforted by the prospect that the shortcut to their unfulfilled dreams lies in the fact that they just haven’t quite found the secret to tap this vast, allegedly unused cerebral reservoir.
Why would a neuroscientist immediately doubt that 90 percent of the average brain lies perpetually fallow? First of all, it is obvious that the brain, like all our other organs, has been shaped by natural selection. Brain tissue is metabolically expensive both to grow and to run, and it strains credulity to think that evolution would have permitted squandering of resources on a scale necessary to build and maintain such a massively underutilized organ. Moreover, doubts are fueled by ample evidence from clinical neurology. Losing far less than 90 percent of the brain to accident or disease has catastrophic consequences. What is more, observing the effects of head injury reveals that there does not seem to be any area of the brain that can be destroyed by strokes, head trauma, or other manner, without leaving the patient with some kind of functional deficit. Likewise, electrical stimulation of points in the brain during neurosurgery has failed so far to uncover any dormant areas where no percept, emotion or movement is elicited by applying these tiny currents (this can be done with conscious patients under local anesthetic because the brain itself has no pain receptors).
The past hundred years has seen the advent of increasingly sophisticated technologies for listening in on the functional traffic of the brain. The goal of behavioral neuroscience has been to record electrical, chemical and magnetic changes in brain activity and to correlate them with specific mental and behavioral phenomena. With the aid of instruments such as EEGs, magnetoencephalographs, PET scanners and functional MRI machines, researchers have succeeded in localizing a vast number of psychological functions to specific centers and systems in the brain. With nonhuman animals, and occasionally with human patients undergoing neurological treatment, recording probes can even be inserted into the brain itself. Despite this detailed reconnaissance, no quiet areas awaiting new assignments have emerged.
All told, the foregoing suggests that there is no cerebral spare tire waiting to be mounted in service of one’s grade point average, job advancement, or the pursuit of a cure for cancer or the Great American Novel. So, if the 10-percent myth is that implausible, how did it arise? My attempts to track down the origins of the 10-percent myth have not discovered any smoking guns, but some tantalizing clues have emerged (more are recounted in the references below). One stream leads back to the pioneering American psychologist, William James, in the late 19th and early 20th centuries. In addition to his voluminous scholarly work, James was a prodigious author of popular articles offering advice to the general public. In these exhortatory works James was fond of stating that the average person rarely achieves but a small portion of his or her potential. I was never able to find an exact percentage mentioned, and James always talked in terms of one’s undeveloped potential, apparently never relating this to a specific amount of gray matter engaged. A generation of “positive thinking” gurus that followed were not so careful, however, and gradually “10 percent of our capacity” morphed into “10 percent of our brain.” Undoubtedly, the biggest boost for the self-help entrepreneurs came when the famous adventurer and journalist Lowell Thomas attributed the 10-percent-of-the-brain claim to William James. Thomas did so in the preface he wrote, in 1936, to one of the best-selling self-help books of all time, Dale Carnegie’s How to Win Friends and Influence People. The myth has never lost its steam since.
Other sources for the ubiquity of the 10-percent myth probably come from popular authors’ misconstrual of scientific papers by early brain researchers. For example, in calling (for technical reasons) a huge percentage of the cerebral hemispheres the “silent cortex,” early investigators may have left the mistaken impression that what is now referred to as the “association cortex” had no function. That was far from the researchers’ intention, but that is what seems to have filtered through to the public. Likewise, early researchers’ appropriately modest admissions that they didn’t know what 90 percent of the brain was doing probably fostered the widespread misconception that the leftovers did nothing.
In my quest for the seminal utterance of the 10-percent myth, I frequently came across the claim that Albert Einstein had once explained his own brilliance by reference to the myth–Einstein’s enormous prestige, of course, making it unassailable thenceforth. A careful search by the helpful people at the Albert Einstein archives, however, was unable to provide me with any record of such a statement on his part. So it remains probably just another of those instances where promoters with a point or a buck to make have misappropriated the clout of Einstein’s name to further their own endeavors.
The 10-percent myth has undoubtedly motivated many people to strive for greater creativity and productivity in their lives–hardly a bad thing. The comfort, encouragement and hope that it has engendered helps explain its longevity. But, like so many uplifting myths that are too good to be true, the truth of the matter seems to be its least important aspect.
Neuromyth 4
We only use 10% of our brain
OECD
https://www.oecd.org/education/ceri/neuromyth4.htm
One of the most persistent and widely spread brain myths states that we only use 10% of our brains. What a shock, if we think of the 90% of our brain potential, that we don’t use! Users of an Internet forum tried to explain this phenomenon: “Sure that we do not use all of our brain”, writes one of them, “because then we could not learn new things, as all of the brain capacity would be already used”. Another person, on the contrary thinks: “we only use a part of our brain, the rest serves as a reserve. We continuously lose brain cells. That means: In the course of our life we use all of them!” Apart from these explanations, the 10% myth is used in advertisement campaigns. Most often it is found in connection with certain new-age brain jogging products, which promise the access to huge unused brain areas- but the sellers profit most from these products.
Other people try to extend their brain capacity by making use of various methods. ThusIt has been stated that: “In the traditional Asian meditation techniques the remaining brain percents are used for extending consciousness and as a spiritual exercise”. Consequently, we could learn from Zen monks and yogis to use all of our brain. And for those who won’t go along with meditation, they could acquire a heightened brain capacity more easily: through drugs like cannabis. Just imagine what could be reached through the extension of brain usage: Thought transmission, extremely high intelligence, as well as telekinesis.
The truth, however, is less fantastic. There is absolutely no scientific evidence, which confirms this myth, not even to some extent. Various theories on the origin of this myth exist, but there is no significant evidence to suggest that we only use 10 or any other specific or limited percentage of our brains. On the contrary, all existing data shows that we use a 100% of our brains.
Were does this myth come from?
Today it is difficult to determine from whom this myth stemmed, and how it could have spread so widely. However, it can be traced back to the late 19th century in advertisements and brochures for self-help. Not to mention that, Albert Einstein once said to a journalist that he only used 10% of his brain, as an answer to a question concerning his intelligence. This quotation of Einstein, however, has never officially been recorded. The myth then became famous through Dale Carnegie’s best-seller “How to Stop Worrying and Start Living” and through Uri Geller, who explained his “spoon magic” by better usage of the brain.
While no brain scientist has ever spoken about 10%, researchers still contributed to the 10% myth. The ignorance, which ruled at the beginning of brain research, could have contributed to the myth. In the 30s, the researcher Karl Lashley explored the function of certain brain areas with electric shocks. These showed up no effects in many brain regions. Hence, he concluded that these regions did not have any function. Thus, the term “silent cortex” was created. Today, however, this thesis has turned out to be wrong. Another possibility for the origin of this myth is the ratio of glia cells to neurons in the brain, which is 10:1. Glia cells “only” support neurons in their functioning. But it is the neurons that are used for information processing, and thereby for our thinking and feeling.
Possibly, the success of the myth can be ascribed to our hope to overcome human constraints. How great would it be, if there were such an enormous, unused reservoir for us to tap! But there are arguments, that these wishes won’t come true.
Arguments against the 10% myth: We use 100% of our brain.
“90% of the brain are continually lying fallow”- a neuroscientist would immediately doubt that this statement is true for the following reasons:
1. Evolution does not allow any wastefulness. Wastefulness causes an exclusion of the gene pool.
Like all other organs, our brain has been shaped by natural selection. While the brain only weighs 2% of the total body weight, it uses 20% of the whole energy. Thus, brain tissue is metabolically expensive to grow and run. Regarding these high costs, it is improbable, that evolution would have permitted the wasting of resources on a scale necessary to build such an inefficient and only partially used organ! A brain that only works with 10% of its power would not be worth the high costs and thereby human beings with their large brains would have already been excluded from the gene pool.
2. Examples from clinical neurology show that losing far less than 90% of brain tissue has serious consequences.
Imagine the following horror scenario: a masked man holds his gun onto your forehead and menaces: “Give me your money or I will shoot!” According to the 10% myth, you would placidly refuse his order, as the chance that the bullet hits a brain area, which you actually use, lies only at 10%. But reality is different: Nobody would risk such an injury. No stroke or other trauma is without (at least shortly) consequences. No brain region can be damaged without leaving a person with mental or physical deficits.
But there are stories about people who lived for years with a bullet in their brain or who completely recover from a stroke. The fact that these people are able to lead a more or less normal life is due to an extraordinary capacity of the brain: its plasticity. The brain is extremely good in compensation. Other nerve cells are able to take over the tasks of damaged nerve cells, like in a soccer game: If one player gets the red card, the other players take over his role and compensate for his absence. Thereby the team probably might not play as well as before, but it can still play and go for goals. It might also look as if the played with the red card (or the damaged part of the brain respectively) actually was not used at all. But it would be unwise to conclude from a compensated function that we only need 90% of our soccer players or 10% of our brain.
3. Special functions of the brain regions are known: It is possible to create a map of the brain-so that it becomes clear that there is not an inactive 90%.
So far, electrical stimulation of parts of the brain during neurosurgery has failed to reveal any dormant brain area where no perception, emotion or movement can be elicited through the application of these tiny currents. (This can be done with patients under local anaesthetic, because there are no pain receptors in the brain). Furthermore, neuroscientists were able to localize psychological functions to certain brain areas with the help of other methods, like EEG (electroencephalography), MEG (magnetencephalography), PET (Positron Emission Tomography) or fMRI (functional magnetic resonance imaging). Hence, no inactive areas have been observed in the brain. Even during sleep, no brain area is completely inactive. On the contrary, desiderative activity in certain brain regions would be indicative of a serious malfunction.
Dispelling “Neuromyths”
Centre for Educational Research and Innovation
OECD
This chapter addresses some of the pitfalls that arise when erroneous or unfounded bridges get made between neuroscience and education. This is done by outlining and dispelling a number of “neuromyths”. They include unfounded ideas concerning left-side and right-side thinking, the determinism of developments in infancy, gender differences, and multilingualism. This chapter is highly relevant for all those concerned about learning, and especially those who are keen to avoid faddish solutions without scientific underpinning.
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Neuromyth 1
The brain is only plastic for certain kinds of information during specific ‘critical periods’-thereby the first three years of a child are decisive for later development and success in life.
https://www.oecd.org/education/ceri/neuromyth1.htm
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Neuromyth 2
‘Enriched environments’ enhance the brain’s capacity for learning
https://www.oecd.org/education/ceri/neuromyth2.htm
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Neuromyth 3
There is a visual, auditive and a haptic type of learning
https://www.oecd.org/education/ceri/neuromyth3.htm
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Neuromyth 4
We only use 10% of our brain
https://www.oecd.org/education/ceri/neuromyth4.htm
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Neuromyth 5
Myths about multilingualism
https://www.oecd.org/education/ceri/neuromyth5.htm