Human attention isn’t stable, ever, and it costs us: lives lost when drivers space out, billions of dollars wasted on inefficient work, and mental disorders that hijack focus. Much of the time, people don’t realize they’ve stopped paying attention until it’s too late. This “flight of the mind,” as Virginia Woolf called it, is often beyond conscious control.
So researchers at Princeton set out to build a tool that could show people what their brains are doing in real time, and signal the moments when their minds begin to wander. And they've largely succeeded, a paper published today in the journal Nature Neuroscience reports. The scientists who invented this attention machine, led by professor Nick Turk-Browne, are calling it a “mind booster.” It could, they say, change the way we think about paying attention—and even introduce new ways of treating illnesses like depression.
Here’s how the brain decoder works: You lie down in a functional magnetic resonance imaging machine (fMRI)—similar to the MRI machines used to diagnose diseases—which lets scientists track brain activity. Once you're in the scanner, you watch a series of pictures and press a button when you see certain targets. The task is like a video game—the dullest video game in the world, really, which is the point. You see a face, overlaid atop an image of a landscape. Your job is to press a button if the face is female, as it is 90 percent of the time, but not if it’s male. And ignore the landscape. (There’s also a reverse task, in which you’re asked to judge whether the scene is outside or inside, and ignore the faces.)
To gauge attention from the brain, the researchers used a learning algorithm like the one Facebook uses to recognize friends’ photos. The algorithm can discern “Your Brain On Faces” versus “Your Brain On Scenes.” Whenever you start spacing out, it detects more “scene” than “face” in your brain signal, and tells the program to make the faces you are watching grow dimmer. In turn, you have to focus harder to figure out what you’re seeing, and to succeed at the “game.” In the Princeton face-scene game, college students made errors 30 percent of the time.