We use our brains every second of every day, even when we’re sleeping. The brain is central to everything we do – it’s responsible for processing information, motor control, maintaining homeostasis, learning and memory, and perception. It’s no wonder that the brain is the most complex part of our bodies.

March 16-20, 2015 is the 20th anniversary of Brain Awareness Week. This entire week is dedicated towards increasing public knowledge of ongoing research efforts and the benefits of brain research.

In honor of Brain Awareness Week, here are 5 facts and 5 myths about your brain:


1. The brain, on average, weighs three pounds.

The average adult human brain is about 5.5 inches wide and 6.5 inches long. In comparison, the elephant brain weighs roughly 12 pounds, but the biggest brain of all is the sperm whale’s 17 pound brain

2. The brain has 100 billion or more nerve cells and can receive and send out signals at a rate of 200 miles per hour!

Specifically, neurons are the nerve cells that transmit signals to and from the brain. The neuron is made up of a cell body, a long tail-like extension called the axon, and the myelin coating that surrounds the axon. A typical neuron can communicate with 1,000-10,000 other neurons or cells in the body. 

3. Your brain uses 20% of the total oxygen and blood in your body.

Oxygen is vital to the brain. Without it, the brain can’t perform its intended functions, which causes downstream effects throughout your entire body. In fact, just 5-10 minutes of oxygen deprivation – for example, in the case of a stroke – can cause permanent damage to the brain. 

4. When awake, your brain can produce enough electricity to power a small lightbulb.

The brain uses electrical signals to send information throughout the body. As each neuron transmits information, they fire off action potentials in a synapse. These action potentials usually happen in less than a second and create a voltage charge of tens of millivolts. Adding together all the neurons in the brain, those seemingly small voltage amounts add up to quite a lot of electrical activity going on in your head!

5. Sleep deprivation affects the brain in multiple ways, including impairing judgement and slowing reaction speeds.

Scientists have shown that sleeping after learning new information is essential. We all know that sleep is good for you but it’s specifically essential for learning. Without “slow-wave” sleep, a type of non-REM sleep that happens earlier in the night, the brain can’t process new information as well, which hinders the learning process.


1. You only use 10% of your brain.

This very false statement has somehow propagated through time and popular culture so well, that now it’s accepted as a fact. While it’s true that we don’t use our brains to their full potential on a daily basis, we do use multiple areas in our brains at once and most of the brain is active almost all of the time.

2. Your brain forgetting things is bad.

The brain has to process and sort through an incredible amount of sensory inputs and information every single day. Deleting some of the unnecessary information actually helps the brain retain its plasticity, or how the brain reorganizes its neural pathways in response to emotions, environment changes, or new experiences. These functional changes become long lasting when we learn or memorize new information.

3. Your brain loses thousands of neurons everyday and you can’t replace them.

Throughout the aging process, a healthy person will lose some brain cells but the loss is limited to a small amount. With the exception of injury or brain diseases, an area of the brain called the hippocampus continuously makes new neurons so that the total number of neurons in the brain stays relatively constant throughout life.

4. A bigger brain is a better brain.

Brain sizes can vary from person to person but that doesn’t necessarily mean a bigger brain has more neurons than a smaller brain. The measure of “neuronal density” is a bigger factor when it comes down to looking at numbers for neurons in the brain. What’s more important that just sheer numbers of neurons, is how your brain is connected within itself. This is why even though Albert Einstein’s brain was quite small compared to the average person’s, we can all agree he was quite smart. 

5. It’s all downhill after age 40.

While some brain functions decline as you get older, others actually get better with age. Some examples of this include vocabulary, social skills, and regulating emotions. Even though you might not be able to out-compete kids at concentration or memorization games, the old adage of “older and wiser” can still hold up to be true. 

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