Bradley Cooper's Underrated 2011 Sci-Fi Movie Relies On A Persistent Science Myth

Back in 2011 — long before Bradley Cooper climbed the director's chair — he was three hundred steps ahead of the game in the sci-fi movie "Limitless." The film was  based on Alan Glynn's novel "The Dark Fields" and stars Cooper as struggling writer Eddie Morra, who unlocks dramatically expanded mental capabilities after taking a drug called NZT. This wonder pill turns him into a high-level intellect who can rapidly turn his life around in all sorts of ways, although there are serious side effects. Things then get even sketchier when our hero finds himself on the run from suits who are desperate to keep this new drug a secret.

The film's main hook is that humans only use 20% of our brains and NZT taps into the remainder, although you might have heard we truly only use half that much. The concept of untapped brain power was also central to Scarlett Johansson's 2014 film "Lucy," and the 10% figure has hung around for over a century. Like a lot of sci-fi movies, "Limitless" focuses more on the fiction while giving a little less attention to the science of it all. The reality is that humans use a fair chunk of the old noggin and we don't need a mysterious pill to activate it for use.

An article at Yale Scientific by Liya Lomsadze of CapitalRx links the 10% brain-use fallacy to early 1900s experiments by psychologist Karl Lashley. Lashley and his team experimented with rats to see how different parts of their cerebral cortices were triggered in mazes and visual discrimination tests. The assumption was that only a small bit of rats' brains were being used because they were still able to function normally and learn with large pieces removed. While that is unsettling it's far from the only disturbing experiment involving rat brains, and UCLA scientists later concluded that their damaged organs were redistributing problem-solving functions to the tissue that remained. 

Their research showed that 20 percent of the neurons in the lateral amygdala fired at once during memory formation, although signals were distributed to other zones during subsequent trials. According to Lomsazde's article this proved that "while there may be an upper limit to the amount of brain cells involved in any given action, there seems to be no completely unused reservoir of brain matter used." Urban legend moves faster than scientific facts, though, and the 10% brain use myth actually outlived Lashley (who died in 1958).  Keeping this in mind while watching "Limitless" might interfere with your suspension of disbelief, but this wouldn't be the first sci- fi film to be based on a false premise. Don't be too hasty to dismiss the science in every movie you see, though; NASA scientists vouch for the plausibility of these sci-fi movies.