Christopher Nolan has always been fascinated by perception and memory, ideas that have defined his films since Following and Memento. With Inception, he’s made a fantastic action film rooted in the human subconscious, and though the technology and premise of the film are the stuff of fancy, the story has plenty to teach viewers about the ways our brains really work. Some of the revelations may be old news to those who studied psychology in college, but there’s always more to learn about the fascinating and often unexplored world of dreams. Read on to discover what Inception can teach you about your brain. (Heads up: Plenty of plot spoilers to follow.)
There are five stages of sleep, each one progressively deeper and stronger. Dreaming happens in the fifth and final stage, known as rapid eye movement (REM) sleep, which kicks in about an hour and a half after you go to sleep. One of the reasons Cobb and the rest of his team use such powerful drugs is that, in order to move through the dream world, they have to go very deep, very quickly, in order to send their brains into REM sleep.
You’re pretty much paralyzed while dreaming
One of the key concepts of Inception deals with how people using artificial sleep methods to enter the dream world are essentially left paralyzed while doing so. This is why one member of the team is left behind to watch the others and regulate their activity. The thing is, it’s true. During REM sleep, an amino acid called glycine is released by the brain stem and onto what is called motoneurons, which work to conduct impulses from the spinal cord out to the body. Glycine inhibits their ability, which effectively paralyzes your body during dreaming, likely as an evolutionary way to make sure you don’t physically respond to the images in your head.
The inhabitants of the world of Inception are often addicted to dreaming, with some of them returning again and again to artificial sleep just to keep dreaming for hours at a time. It’s an interesting interpretation of a very real phenomenon: your brain, some researchers say, needs dreams to function properly. A Harvard psychiatrist published a paper in fall 2009 posits that dreams help the brain get warmed up for the day ahead, with REM sleep and its attendant images the mental equivalent of stretching before exercise. It’s a novel but powerful idea that goes a long toward explaining the benefits and purposes of dreams.
Dreams can be controlled
The entire plot of Inception hangs on this one idea. It’s what lets Cobb and his gang do their jobs, allowing them to manipulate and manage dream environments for total strangers. Although the phrase isn’t mentioned in the film, what they’re doing is a version of lucid dreaming. Lucid dreaming is what it sounds like: dreaming with clarity and understanding, in which you are able to react to and control your dream without waking up. It’s an acquired skill that not many have, though researchers have done their best to understand and implement the process. German psychologist Paul Tholey developed what he called the “reflection technique,” which required users to constantly suspect real life to be a dream, hoping that the habit would carry over to the dream state and allow for recognition and control of dreams.
It’s one thing to control your dreams lucidly; it’s another to actually create them. Inception revolves around the idea of artificially constructed dream space built by a dream architect responsible for designing safe but believable worlds into which the dreamers can insert themselves. How close is that to reality? Closer than you probably think. Many therapists and researchers use a technique called “dream incubation” as a way to help patients deal with terrifying and traumatic nightmares, and the incubation process works on the brain similar to the rules of Inception. As patients drift off to sleep, they tell themselves to prepare for possible nightmares by having escape routes; someone who dreams of fire might tell themselves that, should the dream occur, they’ll find a fire hose and exit to safety. The process can also work for basic problem-solving, as patients write about a problem before bed and think about it as they go to sleep, often visualizing it in their dreams.
“Kicks” are real
The dreamers in Inception are pulled back into consciousness via “kicks,” sudden drops (often from a chair) that startle their body into waking. The kicks are based on hypnic jerks, the twitches that often accompany a sense of falling that occurs when someone is drifting off to sleep. Hypnic jerks often wake people up even as they’re falling asleep, thanks to the physical twitch, and it’s this very real brain phenomenon that Inception deftly uses on all its dream levels, requiring everyone to synchronize their kicks and ride a wave of them back up to the real world.
The bulk of Inception deals with a plot to plant an idea in Fischer’s subconscious so that, upon waking, he’ll have the urge to do something he previously didn’t want to do. The plot sounds at best like something out of science-fiction, using dreams to plant ideas that come to fruition upon waking. But there’s a nugget of truth in there about how our brains really work while we dream. Neurologists have recently found that sleep might actually be an invaluable part of the problem-solving process, allowing ideas to marinate and letting people see problems in a new light upon waking. A possible incubation period for ideas that happens while dreaming might be able to increase people’s ability to make inferences and connections in their lives by one-third. So if there’s a problem you can’t seem to solve, sleep on it. You just might figure it out.
Throughout Inception, Cobb is haunted by the memories of his wife, Mal, who killed herself after going crazy while stranded in limbo. Every time he travels down into the subconscious world of dreams, even in someone else’s brain, he’s attacked by a manifestation of his anger and guilt that’s transformed into a murderous version of Mal. He keeps her memory locked up in his subconscious, never healing, and he suffers the consequences when she/it gets out. That kind of thing can happen to you and me, according to researchers. In fact, most of our dreams are negative in some way, functioning as escape hatches for our darkest fears, worries, and memories. New traumas can trigger the release of old, suppressed horrors that make themselves known again in our dreams, as was the case with the man who was abused as a child and found himself reliving the horror in his adult dreams after being burglarized. There are many ways to deal with past problems, whether it’s therapy, dream incubation, or something else, but the lesson from the movie is the one to carry into real life: you have to deal with the bad stuff, or it will tear you apart.