

The brain is the most complex organ in the human body. Many believe that a person only ever uses 10 percent of their brain. Is there any truth to this?

A person's brain determines how they experience the world around them. The brain weighs about 3 pounds and contains around 100 billion neurons — cells that carry information.

In this article, we explore how much of the brain a person uses. We also bust some widely held myths and reveal some interesting facts about the brain.

How much of the brain is used represented by digital render of brain activity.Share on Pinterest
Studies have debunked the myth that humans use only 10 percent of their brain.



The 10 percent myth was also debunked in a study published in Frontiers in Human Neuroscience.

One common brain imaging technique, called functional magnetic resonance imaging (fMRI), can measure activity in the brain while a person is performing different tasks.

Using this and similar methods, researchers show that most of our brain is in use most of the time, even when a person is performing a very simple action.

A lot of the brain is even active when a person is resting or sleeping.

The percentage of the brain in use at any given time varies from person to person. It also depends on what a person is doing or thinking about.

It's not clear how this myth began, but there are several possible sources.

In an article published in a 1907 edition of the journal Science, psychologist and author William James argued that humans only use part of their mental resources. However, he did not specify a percentage.

The figure was referenced in Dale Carnegie's 1936 book How to Win Friends and Influence People. The myth was described as something the author's college professor used to say.

There is also a belief among scientists that neurons make up around 10 percent of the brain's cells. This may have contributed to the 10 percent myth.

The myth has been repeated in articles, TV programs, and films, which helps to explain why it is so widely believed.

Like any other organ, the brain is affected by a person's lifestyle, diet, and the amount that they exercise.

To improve the health and function of the brain, a person can do the following things.

Eat a balanced diet

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Nuts are high in omega fatty acids and antioxidants, making them beneficial to brain health.

Eating well improves overall health and well-being. It also reduces the risk of developing health issues that may lead to dementia, including:

  • cardiovascular disease
  • midlife obesity
  • type 2 diabetes

The following foods promote brain health:

  • Fruits and vegetables with dark skins. Some are rich in vitamin E, such as spinach, broccoli, and blueberries. Others are rich in beta carotene, including red peppers and sweet potatoes. Vitamin E and beta carotene promote brain health.
  • Oily fish. These types of fish, such as salmon, mackerel, and tuna, are rich in omega-3 fatty acids, which may support cognitive function.
  • Walnuts and pecans. They are rich in antioxidants, which promote brain health.

There is a selection of walnuts and pecans available for purchase online.

Exercise regularly

Regular exercise also reduces the risk of health problems that may lead to dementia.

Cardiovascular activities, such as walking briskly for 30 minutes a day, can be enough to reduce the risk of brain function declining.

Other accessible and inexpensive options include:

  • bike riding
  • jogging
  • swimming

Keep the brain active

The more a person uses their brain, the better their mental functions become. For this reason, brain training exercises are a good way to maintain overall brain health.

A recent study conducted over 10 years found that people who used brain training exercises reduced the risk of dementia by 29 percent.

The most effective training focused on increasing the brain's speed and ability to process complex information quickly.

There are a number of other popular myths about the brain. These are discussed and dispelled below.

Left-brained vs. right-brained

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Research suggests that a person will not be dominated by either the left hemisphere or right, but that both sides of the brain are used equally.

Many believe that a person is either left-brained or right-brained, with right-brained people being more creative, and left-brained people more logical.

However, research suggests that this is a myth — people are not dominated by one brain hemisphere or the other. A healthy person is constantly using both hemispheres.

It is true that the hemispheres have different tasks. For instance, a study in PLOS Biology discussed the extent to which the left hemisphere is involved in processing language, and the right in processing emotions.

Alcohol and the brain

Long-term alcoholism can lead to a number of health problems, including brain damage.

It is not, however, as simple as saying that drinking alcohol kills brain cells — this is a myth. The reasons for this are complicated.

If a woman drinks too much alcohol while pregnant, it can affect the brain development of the fetus, and even cause fetal alcohol syndrome.

The brains of babies with this condition may be smaller and often contain fewer brain cells. This may lead to difficulties with learning and behavior.

Subliminal messages

Research suggests that subliminal messages can provoke an emotional response in people unaware that they had received emotional stimulus. But can subliminal messages help a person to learn new things?

A study published in Nature Communications found that hearing recordings of vocabulary when sleeping could improve a person's ability to remember the words. This was only the case in people who had already studied the vocabulary.

Researchers noted that hearing information while asleep cannot help a person to learn new things. It may only improve recall of information learned earlier, while awake.

Brain wrinkles

The human brain is covered in folds, commonly known as wrinkles. The dip in each fold is called the sulcus, and the raised part is called the gyrus.

Some people believe that a new wrinkle is formed every time a person learns something. This is not the case.

The brain starts to develop wrinkles before a person is born, and this process continues throughout childhood.

The brain is constantly making new connections and breaking old ones, even in adulthood.

Now that we have dispelled some commonly held myths, here are some facts about the brain.

Energy use

The brain represents around 2 percent of a person's weight but uses 20 percent of their oxygen and calories.


First established in 1945, scientists estimate that the brain is around 73 percent water.

Keeping the brain hydrated is important. Being dehydrated by as little as 2 percent may impair a person's ability to perform tasks that involve attention, memory, and motor skills.


Cholesterol is a type of fat that people often consider bad for their health.

It's true that eating too much cholesterol is bad for the heart. However, many people are unaware that cholesterol plays a significant role in a person's brain.

Without cholesterol, the cells in the brain would not survive.

Around 25 percent of the body's cholesterol is contained within the brain cells.

Because of the organ's complexity, scientists are still learning about the brain.

The notion that a person uses only 10 percent of their brain is a myth. fMRI scans show that even simple activities require almost all of the brain to be active.

While there is still a lot to learn about the brain, researchers continue to fill in the gaps between fact and fiction.