We use only 10 percent of our brains . . . not
This has been repeated in pop culture for a century, implying that we have huge reserves of untapped mental powers. “But the supposedly unused 90 percent of the brain is not some vestigial appendix. Brains are expensive—it takes a lot of energy to build brains during fetal and childhood development and maintain them in adults. Evolutionarily, it would make no sense to carry around surplus brain tissue.”
1) “Brain imaging research techniques such as PET scans (positron emission tomography) and fMRI (functional magnetic resonance imaging) clearly show that the vast majority of the brain does not lie fallow. Indeed, although certain minor functions may use only a small part of the brain at one time, any sufficiently complex set of activities or thought patterns will indeed use many parts of the brain. Just as people don’t use all of their muscle groups at one time, they also don’t use all of their brain at once.”
2) “The myth presupposes an extreme localization of functions in the brain. If the “used” or “necessary” parts of the brain were scattered all around the organ, that would imply that much of the brain is in fact necessary. But the myth implies that the “used” part of the brain is a discrete area, and the “unused” part is like an appendix or tonsil, taking up space but essentially unnecessary. But if all those parts of the brain are unused, removal or damage to the “unused” part of the brain should be minor or unnoticed. Yet people who have suffered head trauma, a stroke, or other brain injury are frequently severely impaired. Have you ever heard a doctor say, “. . . But luckily when that bullet entered his skull, it only damaged the 90 percent of his brain he didn’t use”?”
Regardless of the exact version heard, the myth is spread and repeated, by both the well-meaning and the deliberately deceptive. The belief that remains, then, is what Robert J. Samuelson termed a “psycho-fact, [a] belief that, though not supported by hard evidence, is taken as real because its constant repetition changes the way we experience life.”
March 12-18, 2018 is Brain Awareness Week (BAW) is a nationwide effort organized by the Dana Alliance for Brain Initiatives and the Society for Neuroscience to promote the public and personal benefits of brain research.