Researchers at Georgetown University have found new evidence that as people acquire skills, their brains physically reorganize, allowing well-practiced tasks to become automatic. The findings challenge the long-held idea that humans are incapable of truly multitasking and suggest that with enough experience, the brain can perform certain activities at the same time, rather than simply switching between them quickly.
This discovery could have implications beyond everyday life. This could help scientists better understand how habits form, why some behaviors are difficult to change, and how future artificial intelligence systems can build new skills from previous learning.
“This is a new stepping stone in understanding how the brain learns,” said lead author Dr. Maximilian Riesenhuber, professor of neuroscience and co-director of the Center for Neuroengineering at Georgetown University School of Medicine. “What’s encouraging is that you can actually learn to multitask. There are actually ways to modify the structure of your brain to use other parts of your brain.”
How the brain automates learned skills
The study expands on decades of research exploring how the brain acquires new abilities. Scientists have learned a lot about the early stages of learning, but little is known about what happens after a skill has been practiced extensively and requires little effort.
Driving is a common example, Riesenhuber explained. Learning to drive requires constant attention at first, but with years of experience, many people can safely hold a conversation, listen to music, and think through problems while driving.
“The question is, how does your brain do it?” Riesenhuber said.
Brain scan reveals changes in neural circuits
To find out, the researchers asked volunteers to classify images of morphed cars into two categories by identifying subtle visual differences. Participants completed more than 30,000 sorting experiments over five to 10 weeks using a game-style smartphone app.
The researchers examined the participants’ brains with fMRI and EEG scans before training began and after the practice period.
During the early stages of learning, the classification task primarily activated the prefrontal cortex, an area responsible for executive functions such as planning, reasoning, and conscious decision-making. This part of the brain typically handles one demanding task at a time, and has long been considered a major limitation of multitasking.
But after a few weeks of practice, the brain activity changed. The same categorization task is now primarily handled by the temporal cortex, an area involved in memory and recognition of complex objects.
“Previous studies have shown that parts of the temporal cortex can be activated by experienced observers, as well as certain object categories such as birds, cars, and even Pokemon, but a limitation of all these studies is that they only target people after they have become experts. Strengths of this study “Because we’re measuring before and after training, we can see that extensive training essentially created category-selective areas in the temporal lobe that weren’t there before,” said lead author Dr. Patrick Cox, who began the study as a graduate student. student in Riesenhuber’s lab and is currently an assistant professor of psychology at Lehigh University.
“This has implications for important real-world scenarios, such as when radiologists, thanks to years of training, can accurately classify masses on radiographs as benign or malignant fairly automatically, often without extensive deliberation,” Cox said.
How brain rewiring enables multitasking
The researchers found that information from the newly developed car-selective area of the temporal cortex can bypass the prefrontal cortex and go directly to brain areas that generate responses.
“Experience restructures the brain to avoid bottlenecks in the frontal lobe. The prefrontal cortex is then freed up to do other things you want to do, increasing your ability,” Riesenhuber explained.
The researchers also found that the more the car sorting task was “offloaded” from the prefrontal cortex, the better the participants were at performing a second task at the same time.
This result challenges the long-accepted idea that humans cannot truly multitask. Instead, many scientists argue that the brain simply switches attention quickly between tasks, creating the illusion that it’s doing both at the same time.
“What we’re showing is that the circuitry actually changes and allows the brain to do two things at the same time,” Riesenhuber said. “This is true multitasking.”
What the findings mean for habits and AI
The results may also provide new insights into compulsive behavior. Well-learned behaviors transfer into brain circuits that are less dependent on conscious control, so simply trying to think of something else may not be enough to break an undesirable habit.
“The first step to forgetting something is understanding where in the brain it’s actually happening,” Riesenhuber said. “This shows why strategies like telling someone to think differently don’t actually work, because their behavior is not under conscious control.”
The researchers also believe the discovery may help explain why humans continue to build new abilities throughout their lives, while current AI systems still struggle to continuously learn previously acquired knowledge without interruption.
According to Riesenhuber, transferring well-learned skills to the temporal cortex frees up the prefrontal cortex to focus on new tasks, allowing existing knowledge to serve as the basis for future learning. Today’s AI systems generally lack such flexible architectures.
The researchers now plan to investigate exactly what signals move learning from one brain region to another, ultimately determining what kinds of tasks can be performed in parallel.
“Another really interesting question is: What kinds of tasks can we learn enough to perform in parallel?” Cox says. “We can walk and chew gum at the same time, but texting while driving is never safe, as it takes your eyes off the road. Ultimately, juggling the two tasks depends on training completely separate neural circuits.”
The study, “Extensive experience restructures neural task circuits to escape frontal bottlenecks and enhance automaticity of categorization,” was published June 4 in the journal Nature. Journal of Cognitive Neuroscience.
In addition to Riesenhuber and Cox, the research team included Georgetown University’s Clara A. Scholl, Marissa L. Laws, Nelson E. Jaimes, and Xiong Jiang. This research was supported by the National Science Foundation (BCS-1232530), the ARCS Foundation, and the Army Research Laboratory (W911NF-24-1-0097). The authors report no personal financial interests related to this study.
