There's a scene from the new film Inception in which the main character, played by Leonardo DiCaprio, has entered another character's mind through a dream and tells him, "I know how to find secrets from your mind — I know all the tricks!"
It's easy for DiCaprio's character to make this claim. After all, he's in a big-budget Hollywood movie. He can do anything he wants, given the right special effects. But can real-life technologies perform these kinds of mind-reading "tricks" too? While we can't use a device to recreate elaborate and shared dreamscapes yet, it may surprise you just how much existing technologies that read dreams and minds can do.
One of the researchers on the forefront of such technology is Jack Gallant, a neuroscientist at the University of California, Berkeley. Gallant has spent the past 10 years heading a neuroscience and psychology lab at Berkeley whose mandate is to tap into the mind to see what it sees. Gallant does this by showing people images and movies while taking a functional magnetic resonance imaging (fMRI) scan of their brains. He uses brain-pattern analysis and computer algorithms to analyze the fMRI scans and build a model of the subject's visual system. Using the model, Gallant can then have his subject watch a completely new movie and reproduce the images the subject has seen with very good accuracy. In other words, he can take the pictures right out of our heads.
Gallant says he can use the same technology to reproduce the images of the dreams from a person's brain. The only problem is that there is no way to verify the accuracy of those images, since only the dreamer ever "sees" them.
Another team of researchers in Japan has been tackling the dream-reading problem from a different direction. Advanced Telecommunications Research (ATR) Computational Neuroscience Laboratories also takes fMRI scans of what the subject sees. Instead of building a model of the visual system, ATR feeds fMRI scans into a computer, which "learns" how to associate changes in brain activity with different images. Lab scientists can reconstruct simple black-and-white images the subject is viewing by analyzing the blood flow in the brain's visual cortex. ATR says reconstructing dreams is harder because the brain signals during sleep may be "noisier," and is now researching how to get more meaningful information from a sleeper's brain.
"It is possible that brain signals during sleep measured by fMRI are too noisy," says Yukiyasu Kamitani, ATR's head of Neuroinformatics. "We are now trying to figure out what we can do to get meaningful information from brain signals during sleep."
Brain-pattern analysis using fMRI is also being researched for other applications. John-Dylan Hanes, a senior researcher at the Max Planck Institute for Human Cognitive and Brain Sciences in Germany, can predict your actions before you take them. Specifically, he has been using fMRI scans to explore the relationship between brain activation patterns and real-life behavior. In one study involving free will, Hanes showed that he could analyze the scans to predict accurately whether subjects would press a button with their left or right hand seven seconds before they actually pressed it.
Another idea Inception director Christopher Nolan based his movie on was lucid dreaming, in which the sleeper is aware he is dreaming and can even exert some control over the dream. Some lucid dreamers can do so naturally, but others must learn it — and one device claims to help. Called NovaDreamer, the device is a sleep mask that detects when to give cues — flashing lights — to the dreamer to stimulate awareness, but not wake him. NovaDreamer was developed by Stephen LaBerge, a psychophysiologist who popularized the concept of lucid dreaming while teaching at Stanford University for 25 years.
While mind-reading technology pushes ahead, there are limitations. In Inception, DiCaprio's character is able to detect higher-order thoughts, like internal speech or decision-making, and even "steal" them. Gallant says that how the brain processes information on thoughts isn't understood well enough yet to "decode," or read, them. As such, scientists can't yet reproduce or capture an explicit thought like "I want to go skydiving" by peering into the mind alone.
And finally, like the title of the movie suggests, is it possible for "inception" to occur — to be able to plant a new idea into someone's mind? There is a way to currently inject very crude signals into the brain. A device called a brain pacemaker implanted in the brain stem can send electrical impulses to specific parts of the brain. It is similar to a pacemaker for the heart, and also has medical applications. The brain pacemaker is used in some patients to mitigate symptoms of diseases like Parkinson's with pulses that affect certain neurons.
But the ability to plant an actual higher-order thought remains, at least for the time being, pure fiction.
"You have to have a way to manipulate specific neurons and synapses in specific ways — and that's really difficult and not going to happen anytime soon," says Gallant. "I think it's legitimate for some people to have some concerns about brain-reading technology being used for bad things, but nobody has to be worried about one of those bad things being writing stuff to the brain."