Posted on November 18, 2012 · Posted in Brain InjuryI bet most people have heard that human beings only use 10 percent of their brains. I certainly have. There is just one small problem with that notion: It is wrong. We use 100 percent of our brains.

Christopher Chabris, a Union College psychology professor, and Daniel Simone, a psychology professor at the University of Illinois, talk about the “10 percent myth” in a column they wrote that was published in The Wall Street Journal Saturday.http://online.wsj.com/article/SB10001424127887324556304578119351875421218.html?mod=googlenews_wsj

In fact, the article seeks to debunk three popular myths about the brain, with two of them relating to learning. The authors first of all assert that the idea that we only use 10 percent of our brain “is patently false,” in that we use our  whole brain. Those areas that light up in a brain scan are active, but they aren’t the only part of a  brain working. They are just the most active parts.

We do not use only ten percent of our brains.

Brain research has shown, time after time, that even relatively mundane tasks such as reading a sentence¹ or listening to music² involve activation of almost all of our brain. Additionally, countless lesion studies (research on people who have suffered an injury to the brain) clearly show that no matter which part of the brain is injured, there are always functional consequences.

From an evolutionary perspective, it would also be quite nonsensical for our brains to be this big (so big, that every woman who’s ever given birth knows it requires almost superhuman strength and a whole lot of stitches to pop out a human baby) if only ten percent of it was functional.

The old saw that we use just 10 percent of our brainpower isn't true, but we now know that neurons make up just 10 percent of our brain cells. The other 90 percent, which account for about half the brain's weight, are called glia, which means "glue" in Greek. Neuroscientists used to think glia were simply the sticky stuff that holds neurons together. But recent research has shown glia to be much more. A 2005 paper in the journal Current Opinions in Neurobiology laid out the roles of these unsung cells, which range from mopping up excess neurotransmitters to providing immune protection to actually promoting and modulating synapse growth and function. (Synapses are the connections between neurons.) It turns out the silent majority isn't so silent after all.

The old saw that we use just 10 percent of our brainpower isn't true, but we now know that neurons make up just 10 percent of our brain cells. The other 90 percent, which account for about half the brain's weight, are called glia, which means "glue" in Greek. Neuroscientists used to think glia were simply the sticky stuff that holds neurons together. But recent research has shown glia to be much more. A 2005 paper in the journal Current Opinions in Neurobiology laid out the roles of these unsung cells, which range from mopping up excess neurotransmitters to providing immune protection to actually promoting and modulating synapse growth and function. (Synapses are the connections between neurons.) It turns out the silent majority isn't so silent after all.

Not only have various studies of the brain using neuroimaging debunked this myth, common sense does as well. Think about it: why would we have evolved such large brains if we only used 10% of them? I mean, if we only used 10% of our brains, our brains would only need to be 10% the size they are! Why would nature create so much useless grey matter? It’s like, if we only ever  needed two fingers, we wouldn’t have evolved ten!

Although the 10% use of our brain is a myth, what might be closer to the truth is that we use 100% brains at max capacity at any given moment. For instance, if I were to sit down and read a book in silence, areas of the brain associated with music and large muscle movements would be relatively inactive (at least not working at max capacity). However, when I stand up, walk to my radio, and turn on some music, those parts of the brain then activate while the areas associated with reading grow quieter. Given the diverse activities throughout any given day, it can be said that we basically use 100% of our brains on a daily basis.

this notion may actually be a misinterpretation of the classic research by the great Wilder Penfield

'homunculus.'

What I learned from the historical record is that it was this observation that led to the incorrect view that humans use only 10% of their brains. In truth, many areas that lead to no effect when stimulated by electrode are important "association areas" that connect other areas of the brain, permitting communication between two brain regions. Such interaction between areas is notable in the classic McGurk effect, in which what one sees influences what one hears. (Click here for a dramatic demonstration.) Areas whose stimulation leads to no discernible effect may also consist of networks whose function is not directly perceptual, mnemonic, or motor.

But we need all of our brain. Regardless of what we’re doing, even if we’re asleep, all parts of our brain are working. New brain-imaging techniques, such as functional MRI scans, can measure how much energy is being used in each part of the brain. They show that we regularly use all of our brains. They also show that during any particular task, certain parts of the brain are working harder than others.

So the notion that we use just 10 percent of our brains isn’t true.

Other people have remarkable computational powers: They can multiply two large numbers instantly. They don’t have physically bigger brains.