One lasting neurological myth involves the percentage of brain matter that humans actually “use.” A commonly cited “fact” is that humans only use 10 to 20 % of their brains. In fact, every part of the brain is responsible for a different thought or life-maintenance mechanism. We might only use a certain part of our brain for movement or critical thinking, but there is activity throughout an entire (healthy) brain during a typical day. Not so long ago when people suffered brain damage to areas such as the frontal or parietal lobes, and still were shown to be functional, it was erroneously assumed that these areas where not needed and hence the idea (myth) that we only use a small portion of our brains was born. Using technology such as magnetoencephalography or fMRI, scans show activity coursing through the entire brain all the time, even at rest and during sleep. Not all 100 billion neurons are firing at once (this would be akin to an electrical storm and not at all functional and in fact, similar to an epileptic seizure). But neurons do exist in a constant state of resting potential, that is, potentially ready to propagate their information to the next neuron. In fact, it has been estimated that between 1-16% of our brain cells are active at any given moment, as this is the lower limit to sustain consciousness (see Tononi et al., 2005).
As John Henley, a neurologist at the Mayo Clinic explained in Scientific America, Do People Only Use 10% Of Their Brains, “Even in sleep, areas such as the frontal cortex, which controls things like higher level thinking and self-awareness, or the somatosensory areas, which help people sense their surroundings, are active, …we use virtually every part of the brain, and that [most of] the brain is active almost all the time’
Another point that should further put the 10% myth to rest is to consider the amount of energy our brain uses just to keep the neurons at their resting potential. Humans use an astonishing 10% their daily energy intake (whether that be in the form of glucose of ketone bodies- more on that later) just to keep 1,5 kilograms ready to function. This percentage goes up dramatically as the brain, through the mind, is engaged. If we only used a small portion of our brain, there would be no necessity to use all that energy.
We are already using 100% of our brain and thus, the more intriguing question to explore is tapping into the vast reserves of the potentiality of our minds.
See Richard Cytowic’s very engaging video on using 100% of our brain.