Common misconceptions about the brain

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There are many misconceptions about the brain and human brain perpetuated through urban legends, mass media, and the promotion of dubious products to consumers.^[1]

[edit] About function

• Humans use only 10% or less of their brain. There is no scientific basis for this assertion. Many functional brain imaging studies show activated regions encompassing well over 10% of the brain. Perhaps the most remarkable thing about this myth is that nobody has ever been able to pin down its origin. Some possibilities have been discussed by Benjamin Radford^[2], Eric Chudler^[3], and The Two Percent Company^[4].
  • This misconception most likely arose from a misunderstanding (or misrepresentation in an advertisement) of neurological research in the late 1800s or early 1900s 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 up to that time (accounts differ on this point).^{[citation needed]}
  • Another possible origin of the misconception is that only 10% of the cells in the brain are neurons; the rest are glial cells that, despite being involved in learning, do not function in the same way that neurons do.
  • Einstein is reported as quipping that people typically only use 10% of their brains. The popular press took this as fact, although the comment was meant only facetiously.^{[citation needed]}
  • Lower level of brain activation does not mean a lower performance of cognitive functions; this variable has confounded scientists, because some 'gifted' individuals showed less activity than the average person. Haier proposed that indeed more gifted individuals might possess more efficient brain circuits.^{[citation needed]}
  • 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. However, there is still no proof of this, and many neurologists say that this is not possible.^{[citation needed]}
• Learning can be achieved more powerfully through subliminal techniques. The extent to which subliminal techniques can influence learning depends largely on what level of perception the techniques affect.^{[citation needed]}

[edit] About structure

• There are holes in the brain. Often lesions in the brain, from injury, disease, or drug use, are described as 'holes', however, these 'holes' are in fact not cavities, most often are simply inactive areas of the brain where neurons no longer fire.^{[citation needed]}
• The human brain is firm and grey. The fresh/living brain is actually very soft and generally yellow/grey. It does not become firm and grey until it has been preserved with various chemicals/resins.^{[citation needed]}
• Mental abilities are absolutely separated into the left and right cerebral hemispheres. Some mental functions such as speech and language (cf. Broca's area, Wernicke's area) tend to be localized to specific areas in one hemisphere. If one hemisphere is damaged at a very early age, however, these functions can often be recovered in part or even in full by the other hemisphere. Other abilities such as motor control, memory, and general reasoning are spread equally across the two hemispheres. See lateralization of brain function.^{[citation needed]}
• New neurons cannot be created, they only die as one ages. In fact, new neurons can grow within the mature adult brain; this process is known as neurogenesis. The scientific consensus, however, is that neurogenesis only occurs in the hippocampus and the olfactory bulb. Regardless of neuron growth or death, brain function and capabilities can be learned and developed throughout life.^{[citation needed]}
• The brain cells do not duplicate at all after it has developed (around late childhood). Although most of the brain does not grow, the cells in the hippocampus are still growing.^{[citation needed]}

[edit] References

[edit] See also

• Brain
• Human brain