Brain can multitask after intense mental training

The participants of the experiment trained to sort modified images of cars into two categories. The task was to learn to notice subtle differences between the images. In total, the participants completed more than 30,000 trials over a period of 5-10 weeks, using a special mobile app in the form of a game.

Before and after the training sessions, the scientists scanned the volunteers’ brains using fMRI and EEG. The results were quite revealing.

At first, when the participants were just learning the task, their prefrontal cortex was active. This area is responsible for thinking and executive functions, but it has an important limitation: it can usually only focus on one task at a time.

However, after a few weeks of practice, the situation changed. The process of sorting images shifted to the temporal cortex, a part of the brain that is responsible for memory and the recognition of complex objects.

Patrick Cox, the first author of the study, highlights the key advantage of this research: scientists were able to track changes before and after the training. They saw how a special area was formed in the temporal lobe, responsible for a new category of tasks — before the training, it was not there.

It turned out that information about objects (in this case, cars) now went not through the prefrontal cortex, but directly to those areas of the brain that are responsible for performing actions. This mechanism allows the prefrontal cortex to be freed for other tasks — and it is this that allows you to truly do two things at the same time.

The more the sorting skill was transferred from the prefrontal cortex, the better the participants were able to perform another task in parallel. This directly contradicts the old theory that the brain is not capable of multitasking, but only of quickly switching between tasks. The structure of brain function does indeed change, allowing for the simultaneous execution of two tasks. These findings provide valuable insights into compulsive behavior. When a skill becomes automatic, it shifts to areas of the brain that are less subject to conscious control. Therefore, Reisenhuber explains, advice about just thinking about something else often doesn’t work ‑ the person no longer controls the action on a conscious level.

It has also been found that people are able to accumulate skills: new knowledge builds on existing knowledge. The brain moves the learned actions to the temporal cortex, freeing up space in the prefrontal cortex, allowing you to use old knowledge as a basis for learning new things. Modern artificial intelligence systems cannot yet effectively build learning chains.

Now, scientists plan to study in more detail how the brain moves skills from one zone to another and what signals contribute to this. In addition, they want to determine the limits of multitasking: which tasks can be learned to perform in parallel, and which ones cannot.