Researchers have long said that the human brain is not set up to multitask — but new research is challenging that understanding.
Experts previously explained that when we believe we’re multitasking, we’re actually just quickly switching between tasks. That’s because the area of the brain that manages thinking, the prefrontal cortex, can only really handle one thing at a time.
But another region of the brain involved in memory lends a helping hand over time, new research has shown. When people needed to perform image sorting tests over the course of weeks, the tests initially activated the prefrontal cortex and later activated the temporal cortex.
Over time, the brain is remodeled, Maximilian Riesenhuber, a professor of neuroscience at Georgetown University School of Medicine, explained in a statement. The prefrontal cortex passes responsibility to the temporal cortex and is free for “whatever else you want to do, increasing your capacity.”
“What we show is that the circuitry actually changes so the brain can do two things at once,” he said. “This really is true multitasking.”
The researchers wanted to understand why people need to focus when learning a task for the first time and can also do other things simultaneously when they become experienced. For example, long-time drivers are able to listen to music and engage in conversations.
Men and women in the small study were trained to sort morphed images of cars into two categories using an image-sorting app, completing more than 30,000 trials over the course of 5-10 weeks.
The researchers scanned their brains before and after they completed the trials, revealing the change.
“Previous studies have shown that parts of the temporal cortex can be activated by particular object categories in experienced observers – birds, cars, even Pokémon – but a limitation of all of those studies is that they only looked after people became experts. The strength of this study is that it is longitudinal: We measure before and after training, so we can see that extensive training essentially put a category-selective area in the temporal lobe that was not there before,” Patrick Cox, an assistant professor of psychology at Lehigh University, said.
Interestingly, some people were found to have better brains for multitasking than others, Riesenhuber told NBC News.
It’s unclear why right now. However, multitasking has been linked to experiencing stress and other mental health impacts, Brown University Health points out. That’s part of why experts say it could actually hinder productivity.
“This is unlocking a whole new set of questions,” he said. “What is the source of that variability? We don’t know yet.”
The findings have implications for understanding compulsive behaviors, the researchers say. They also help to explain why humans are good at continuous learning.
That’s something artificial intelligence is still struggling with, they note, and the research could be applied to better train generative AI.
However, the next step for the scientists is to study the underlying process involved: how learning moves from one part of the brain to the other.
In addition, what are the limits of multitasking as they observed?
“Another really interesting question is what kinds of tasks can be learned well enough to do in parallel,” said Cox.
“We can walk and chew gum at the same time, but looking at our phones to text while driving will never be safe, because we take our eyes away from the road. It comes down to being able to train fully separate neural circuits for two tasks to become compatible,” he added.
