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Ten percent of the brain myth

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The 10% of brain myth is the widely-perpetuated myth that most or all human beings only make use of 10 percent of their brains. It has been variously misattributed to a number of people, including Albert Einstein.[1] By association, it is often suggested that by some process a person may harness this unused potential and in so doing increase their intelligence.

Though many factors of intelligence may be increased with training, the idea that large parts of the brain remain unused is without substantial foundation. Although many mysteries regarding brain function remain, every part of the brain has a known function.[2][3][4]

Origin

One possible origin of the myth lies in the reserve energy theories made by Harvard psychologists William James and Boris Sidis in the 1890s who tested the theory in the accelerated raising of child prodigy William Sidis to affect an adulthood IQ of 250-300; a theory latter famously summarized in 1936 by American writer Lowell Thomas to the effect that “the average person develops only 10 percent of his latent mental ability."[citation needed] There is not a direct relationship between the performance of the brain and its level of activation; this variable has confounded scientists, because some 'gifted' individuals showed less brain activity than those with brain performance considered 'average'. Haier proposed that more gifted individuals might possess more efficient brain circuits.[citation needed]

In reality, the 10% myth most likely arose from a misunderstanding (or public misrepresentation) of neurological research undertaken in the late 19th century or early 20th century when researchers either discovered that only about 10% of the neurons in the brain are firing at any given time or announced that they had only mapped the functions of 10% of the brain at that time (accounts differ on this point). Another possible origin of the 10% myth is that neurons only compose approximately 10% of the cells in the brain; the rest are glial cells that, despite being involved in learning, function differently from neurons. Dr. James W. Kalat, author of the textbook Biological Psychology, points out that neuroscientists in the 1930s knew about the existence of the large number of "local" neurons in the brain, but only knew that these cells were small. The misunderstanding of the function of local neurons may have led to the 10% myth.[5]

Refutation

Neuroscientist Barry Beyerstein sets out seven kinds of evidence refuting the ten percent myth:[6]

  • Studies of brain damage: If 90% of the brain is normally unused, then damage to these areas should not impair performance. Instead, there is almost no area of the brain that can be damaged without loss of abilities. Even slight damage to small areas of the brain can have profound effects.
  • Evolution: The brain is enormously costly to the rest of the body, in terms of oxygen and nutrient consumption. If 90% of it were unnecessary, there would be a large survival advantage to humans with smaller, more efficient brains. If this were true, the process of natural selection would have eliminated the inefficient brains.
  • Brain imaging: Technologies such as Positron Emission Tomography (PET) and Functional Magnetic Resonance Imaging (fMRI) allow the activity of the living brain to be monitored. They reveal that even during sleep, all parts of the brain show some level of activity. Only in the case of serious damage does a brain have "silent" areas.
  • Localization of function: Rather than acting as a single mass, the brain has distinct regions for different kinds of information processing. Decades of research has gone into mapping functions onto areas of the brain, and no function-less areas have been found.
  • Microstructural analysis: In the single-unit recording technique, researchers insert a tiny electrode into the brain to monitor the activity of a single cell. If 90% of cells were unused, then this technique would have revealed that.
  • Metabolic studies: Another scientific technique involves studying the take-up of radioactively labelled 2-deoxyglucose molecules by the brain. If 90 percent of the brain were inactive, then those inactive cells would be show up as blank areas in a radiograph of the brain. Again, there is no such result.
  • Neural disease: Brain cells that are not used have a tendency to degenerate. Hence if 90% of the brain were inactive, autopsy of adult brains would reveal large-scale degeneration.

Perpetuation

The 10% myth has been spread both unwittingly, by individuals believing it to be fact, and deliberately as an advantageous deception. It is frequently used to give strength to arguments in cognitive training or counseling.

The 10% brain myth occurs frequently in advertisements.[7]

Some New Age proponents propagate this belief by asserting that the "unused" ninety percent of the human brain is capable of exhibiting psychic powers and can be trained to perform psychokinesis and extra-sensory perception.[2][6] In addition to the fact that humans use their entire brain, there is no scientific evidence supporting the existence of psychic powers at all.[6]

See also

References

  1. ^ "Do People Only Use 10 Percent Of Their Brains". Scientific American. 7 February 2008. Retrieved 2008-02-07.
  2. ^ a b Radford, Benjamin (8 February 2000). "The Ten-Percent Myth". snopes.com. Retrieved 2006-04-13.
  3. ^ Chudler, Eric. "Myths About the Brain: 10 percent and Counting". Archived from the original on 2006-04-02. Retrieved 2006-04-12.
  4. ^ "A Piece of Our Mind - About Ten Percent". The Two Percent Company. Retrieved 2006-04-12.
  5. ^ Kalat, J.W., Biological Psychology, sixth edition, Pacific Grove: Brooks/Cole Publishing Co., 1998, p. 43.
  6. ^ a b c Beyerstein, Barry L. (1999). "Whence Cometh the Myth that We Only Use 10% of our Brains?". In Sergio Della Sala (ed.). Mind Myths: Exploring Popular Assumptions About the Mind and Brain. Wiley. pp. 3–24. ISBN 0471983039.
  7. ^ "Neuroscience For Kids". Eric H. Chudler, Ph.d(University of Washington, Director of Education and Outreach).
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