Recently, a reporter asked me, "Is it true that we only use 10 percent of our brain?" As a neurologist, I reassured her that this idea is patently false. It's unclear how this myth came to be so widely propagated. Most often, its origin is attributed to William James, a Harvard psychologist, philosopher and physician. In "The Energies of Men," a musing on psychology, published in 1907, James wrote, "We are making use of only a small part of our possible mental and physical resources."
Despite the tremendous advances in neuroscience, it's hard to believe that this belief persists. Scientists estimate that the human brain is composed of 100 billion neurons, with about 100 trillion synapses. It is the most complicated structure in the entire universe! And when you think about it (pun intended), this is not surprising, given the astounding number of tasks and feats our brain performs on a daily basis. Every thought, emotion and mood is generated by our brain. It interprets each sensation and controls every movement. Our brain orchestrates every organ throughout our body via chemical messengers in the blood, called hormones, and through the nerves that extend from the brain and spinal cord. It bestows consciousness and allows us to learn and remember. In fact, there is nothing that we do that is not ultimately overseen by our brain. Even when we sleep, our brain is incredibly active.
Think of your brain as a computer with special programs and software that allow it to perform an amazing array of tasks. At any given time, not every single application is going to be used. For example if you're writing an email to a friend on your computer, you probably will not have your Turbo Tax application open. In the same way, when we are focused on a specific task, the parts of the brain needed for that task will become more active. However, unlike a computer program, which has to be opened in order to be used, every program in your brain is open and ready to go in a moment's notice.
Remarkable advances in neuroscience and brain imaging provide new windows into how the mind works. Through functional MRI and other sophisticated imaging tools, we can view the living brain in real time. Observing subjects as they perform activities during functional MRI scanning allows us to see which parts of the brain become more active (or "light up") during specific activities. The only metabolically silent (or "dead") areas are those regions that have been destroyed by stroke, disease or other injury. Otherwise, every part of the human brain that is alive consumes energy and contributes to the symphony of brain activity.
We also know that our brain uses an incredible amount of energy. Even though it only weighs about 3 pounds, which is only 2 percent of total body weight, a whopping 20 percent of our blood flow goes to our brain. This is because our brain cells are the most highly specialized cells in the human body and require an enormous amount of energy to perform all their important functions.
Perhaps William James meant that we do not use our brain to its full potential. This is another issue altogether. The hit film "Waiting for Superman" is a heart-wrenching exposé of how the United States' educational system fails to develop the inherent potential of all our children. I fully agree with Geoffrey Canada's mission and empowering vision that it is possible to successfully nurture the brain power of each and every child. However, I believe that this message should extend to adults, as well. Developing our brain to its full capacity is a lifetime quest and should not end with formal schooling. The benefits of cultivating our brain throughout our lives is not only personally rewarding, but it ultimately determines our ability to live a meaningful and productive life. In addition, challenging our mind with new experiences and new learning can make our brain more resilient to cognitive decline as we age. Although we can never know the maximal capabilities of the human brain, we should aspire to do everything we can to develop and use this magnificent gift to its utmost potential.
Have a beautiful brain day!