After sorting more than 30,000 car images over several weeks, something remarkable happened in the brains of volunteers at Georgetown University: their neurons rearranged themselves to work faster and more efficiently. The discovery, published by researchers in Washington, D.C., shows that the brain can physically rewire itself with practice — and that this rewiring allows people to truly do two things at once, not just pretend to.
Neuroscientist Maximilian Riesenhuber, PhD, who led the study, said the results turn a longstanding belief on its head. "The encouraging part is that you really can learn to multitask," he said. "There is actually a way to remodel your brain architecture and use other parts of your brain."
Here is what the team found: early in learning, the brain relied heavily on the prefrontal cortex, a region behind the forehead that handles conscious thinking and one challenging task at a time. This is why learning to drive feels so overwhelming at first — every decision demands attention. But after weeks of practice, brain scans showed a dramatic shift. Control of the task had moved to the temporal cortex, a region deep on the sides of the brain that recognizes objects and handles memories automatically.
"Experience remodels the brain to bypass that frontal bottleneck," Riesenhuber explained. "The prefrontal cortex then stays free for whatever else you want to do, increasing your capacity."
The researchers, including first author Patrick Cox, PhD, now at Lehigh University, designed a smartphone app that felt like a game. Volunteers sorted morphed images of cars by spotting subtle differences — a task requiring the same kind of careful judgment as identifying a tumor on an X-ray. The more that sorting became automatic, the better people could handle a second task at the same time.
"What we show is that the circuitry actually changes so the brain can do two things at once," Riesenhuber said. "This really is true multitasking."
The findings also shed light on why habits are so hard to break. Once a skill moves into automatic brain circuits, simply thinking about doing something different is not enough to override it. But understanding how the brain rewires itself could also help scientists build smarter artificial intelligence — systems that learn to build new skills from experience, just as humans do. And for anyone who has ever felt frustrated that they cannot seem to juggle phone calls while driving, the message is hopeful: keep practicing. Your brain is listening.