It's a myth we use just 10 percent of our mind's capacity. In fact, we use it all

Scarlett Johansson’s character Lucy in the eponymous hit movie in theaters has such a highly functioning brain that she develops telepathy and telekinesis. When Lucy is accidentally drugged and harnesses her brain’s full potential, she achieves superhuman powers.

OK, it’s a movie, meaning that we should suspend disbelief. But according to production notes, it’s an action thriller that director Luc Besson “was particularly intent on grounding — at least partly — in scientific fact.”

One problem: Its premise is based on a myth of unknown origin that humans use only 10 percent of their brain’s capacity. 

As author Kate Wong notes in a Scientific American blog: “The notion that we humans have massive reserves of gray matter just sitting there waiting to be summoned into service has obvious appeal, but there is no scientific evidence to support it.”

Indeed, she quotes neurologist Barry Gordon of the Johns Hopkins School of Medicine: “It turns out that we use virtually every part of the brain, and that [most of] the brain is active almost all the time. Let’s put it this way: The brain represents 3 percent of the body’s weight and uses 20 percent of the body’s energy.”

Given that, according to the movie, we could all be using our brains to change the laws of physics, rewind time and control people’s thoughts just like Lucy — admittedly, for most of us, without Ms. Johansson’s movie-star looks.

Ms. Wong notes that Barry L. Beyerstein of the Brain Behavior Laboratory at Simon Fraser University in Vancouver explained in a piece for Scientific American that it “strains credulity” to believe that evolution allowed the brain to be the size it is with such a massive amount being underutilized. (That might explain why movie aliens always have enlarged heads to accommodate their larger brains.)

Additionally, Mr. Beyerstein said, because we use all of our brain, there does not seem to be any area that can be destroyed by strokes, by head trauma or in some other manner without leaving some kind of functional deficit.

L. Dade Lunsford, distinguished professor at the Department of Neurological Surgery at the University of Pittsburgh, has not seen “Lucy” but knows about its flawed premise. 

“The concept we only use 10 percent of our brain is dramatically over-exaggerated,” said Dr. Lunsford, who in 1987 performed the first Gamma Knife brain surgery in North America at what is now UPMC Presbyterian. At the time it was only the world's fifth such procedure. 

“It is not a scientific fact, but so what if it’s in a movie? It’s a pattern in movies that has been explored for a long time with superpowers emerging. From a Hollywood concept, it is not a new idea,” said Dr. Lunsford, pointing to the 1968 movie “Charly.” 

In an Academy Award-winning role, Cliff Robertson played the title character, a man with mental disabilities who undergoes successful experimental surgery to increase his intelligence. Over time, his IQ achieves genius status, only to return to below normal, as it was before the experiment.

Dr. Lunsford said the brain is an extraordinary organ in its own right, even without the superhuman exploits of Lucy or the incredible IQ increase for Charly. So incredible is the brain that science understands only about 10 percent of how it operates, he said. For example, he noted how we can “see” in our mind’s eye the vision of someone we once met, even years before.

“How is that possible? We don’t understand that. Somewhere that memory, that full-color vision, has been embedded in our neurological circuitry and under the right circumstances we can bring that up. I don’t think anyone has a clue how many billions of neurons have to fire to bring up that image.”

While we can’t gain superhuman powers, Dr. Lunsford said we can improve our brain function and memory and delay cognitive deficits of age by training our brains through exercises like crossword puzzles and exercising our body to stimulate the replacement of neurons.

Even though the premise is flawed, he said, there’s no reason not to enjoy a movie like “Lucy,” which has grossed $79.6 million since its July 25 release. 

“Don’t think about it too seriously,” Dr. Lunsford said. “Watch it for entertainment and excitement. A large part of what Hollywood produces isn’t related to reality, but that doesn’t mean it can’t be entertaining.”

Prime example, “Sharknado 2: The Second One.”

“I mean, sharks flying through the streets of New York,” Dr. Lunsford said, chuckling.

Wait, you mean that wasn’t scientifically accurate?

Michael A. Fuoco: or 412-263-1968.

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