Scarlett Johansson plays a lot of tough female characters, so it’s no surprise to see her starring in Lucy, In the film, Johansson portrays a woman who is able to access 100 percent of her brain after being pumped with a drug by smugglers.

The rumor behind the film, which has been around for more than a century, is that humans only use 10 percent of their brain. No matter how much Johansson makes it look cool, the rumor is completely false, reports NBC News.

There are no regions in the brain that are functionless, but can only become so when damage is caused, neuroscientists say. The origins of the myth go back to a study when electrodes were hooked to different parts of the brain. Only 10 percent of the cortex had muscle twitches. Researchers determined the other 90 percent was functionless, or silent. S

Even though director Luc Besson knew the myth was false, he chose to let his imagination create the film. Besson got the idea from a meeting with a young woman who was working on a cure for cancer.

“It was unexpected and we talked for hours,” he said in an interview with Screen Daily.

The drug, which gave Johansson’s character the brain boost, will not be hitting shelves anytime soon—it’s fake. Besson came up with it during the six years he spent brainstorming.

“CPH4 is a fake name but the molecules are real,” said Besson.

While watching Johansson kick butt on screen, remember you could do it too if your brain power was boosted.

Lucy premiers in theaters on July 25.

Image courtesy of INFphotots.com