"We use 100% of our brains." Here is the evidence!

Krishna: NO! Science doesn’t agree with this statement or myth because we have evidence to the contrary. "We use 100% of our brains." Period!

This 10% myth arose in 1800s, need I say this is ancient thinking? And media is keeping this myth alive.

How did we come to believe that 90 percent of our brain is useless? The myth is often incorrectly attributed to 19th-century psychologist William James, who proposed that most of our mental potential goes untapped. But he never specified a percentage. Albert Einstein—a magnet for misattribution of quotes—has also been held responsible. In reality, the concept most likely came from the American self-help industry. One of the earliest mentions appears in the preface to Dale Carnegie’s 1936 mega best seller, How to Win Friends and Influence People. The idea that we have harnessed only a fraction of our brain’s full potential has been a staple for motivational gurus, New Age hucksters, and uninspired screenwriters ever since.Movies are propagating and it’s one of Hollywood’s favorite bits of pseudoscience: human beings use only 10 percent of their brain, and awakening the remaining 90 percent—supposedly dormant—allows otherwise ordinary human beings to display extraordinary mental abilities. In Phenomenon (1996), John Travolta gains the ability to predict earthquakes and instantly learns foreign languages. Scarlett Johansson becomes a superpowered martial-arts master in Lucy (2014). And in Limitless (2011) Bradley Cooper writes a novel overnight (6). Hmmm! And people believe movies and media like hell (6)!

The myth's durability stems from people's conceptions about their own brains: they see their own shortcomings as evidence of the existence of untapped gray matter. This is a false assumption. But self-help books and gurus try to exploit people while keeping this myth alive.

Google images

Now let us see how science disproves this with evidence.

The only time certain regions of the brain are unused is when brain damage or disease has destroyed those areas.

How much of your brain you are using at any given time varies depending on what you are doing or thinking, but it is not true that humans only use a small part of the brain’s power.

From an evolutionary point of view, it is unlikely that larger brains would have developed if there was not an advantage. Certainly there are several pathways that serve similar functions. For example, there are several central pathways that are used for vision. This concept is called "redundancy" and is found throughout the nervous system. Multiple pathways for the same function may be a type of safety mechanism should one of the pathways fail. Still, functional brain imaging studies show that all parts of the brain function. Even during sleep, the brain is active. The brain is still being "used," it is just in a different active state (1). We would not have evolved such large brains if we were only using a tiny portion of them (4).

The brain uses approximately 20% of the body's energy, even though it makes up much less than 20% of total body mass. As with brain size, evolutionary theory suggests that it would make little sense for the body to spend a large portion of its energy resources on an organ that's mostly unused (5).

Decades of studying the human brain and its abilities have shown scientists that every part of the brain has a purpose and is critical to human function. While there is still much to learn, there is also a lot of support for these claims (2).

Functional magnetic resonance imaging (fMRI) allows scientists to investigate how the brain works in a noninvasive way. They can view how blood and oxygen are moving in the brain while a human test participant is performing various mental tasks (or even just resting). These tests make it clear that large regions of the brain are at work during all kinds of activity (2). Researchers have not found any region of the brain that does not serve a function. A study of medical myths noted that numerous types of brain imaging studies show that no area of the brain is completely silent or inactive (3).

Imaging techniques, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), allow doctors and scientists to map brain activity in real time. The data clearly shows that large areas of the brain—far more than 10 percent—are used for all sorts of activity, from seemingly simple tasks like resting or looking at pictures to more complex ones like reading or doing math. Scientists have yet to find an area of the brain that doesn’t do anything (6).

If we needed only 10 percent of our brain, the majority of brain injuries would have no discernible consequences, since the damage would affect parts of the brain that weren’t doing anything to begin with.

We also know that natural selection discourages the development of useless anatomical structures: early humans who devoted scarce physical resources to growing and maintaining huge amounts of excess brain tissue would have been outcompeted by those who spent those precious resources on things more necessary for survival and reproductive success. Tougher immune systems, stronger muscles, better looking hair—just about anything would be more useful than having a head full of inert and useless tissue.

The average human brain weighs about three pounds and comprises the hefty cerebrum, which is the largest portion and performs all higher cognitive functions; the cerebellum, responsible for motor functions, such as the coordination of movement and balance; and the brain stem, dedicated to involuntary functions like breathing. The majority of the energy consumed by the brain powers the rapid firing of millions of neurons communicating with each other. Scientists think it is such neuronal firing and connecting that gives rise to all of the brain's higher functions. The rest of its energy is used for controlling other activities—both unconscious activities, such as heart rate, and conscious ones, such as driving a car (7).

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 (7). Take the simple act of pouring coffee in the morning: In walking toward the coffeepot, reaching for it, pouring the brew into the mug, even leaving extra room for cream, the occipital and parietal lobes, motor sensory and sensory motor cortices, basal ganglia, cerebellum and frontal lobes all activate. A lightning storm of neuronal activity occurs almost across the entire brain in the time span of a few seconds.

Firing brain: source: unsplash.com

Although it's true that at any given moment all of the brain's regions are not concurrently firing, brain researchers using imaging technology have shown that, like the body's muscles, most are continually active over a 24-hour period. "Evidence would show over a day you use 100 percent of the brain”.

We use 100% of our brains. We use virtually every part of the brain, and that [most of] the brain is active almost all the time. This is an evidence based fact.

Come out of your mythical world now and accept evidence and try to see the real scientific world.

Footnotes:

1. Neuroscience For Kids
2. http://Chaarani B, Hahn S, Allgaier N, et al. Baseline brain function in the preadolescents of the ABCD Study. Nat Neurosci. 2021;24(8):1176-1186. doi:10.1038/s41593-021-00867-9
3. http://Vreeman RC, Carroll AE. Medical myths. BMJ. 2007;335(7633):1288-1289. doi:10.1136/bmj.39420.420370.25
4. http://Herculano-Houzel S. The human brain in numbers: a linearly scaled-up primate brain. Front Hum Neurosci. 2009;3:31. doi:10.3389/neuro.09.031.2009
5. http://Watts ME, Pocock R, Claudianos C. Brain energy and oxygen metabolism: emerging role in normal function and disease. Front Mol Neurosci. 2018;11:216. doi:10.3389/fnmol.2018.00216
6. Do We Really Use Only 10 Percent of Our Brain?
7. Do People Only Use 10 Percent of Their Brains?