Opening details

During sleep, neurons working in the brain’s memory center can not only reinterpret past experiences. According to a new study, they also Can look into the future by rehearsing an event that has not yet occurred.

A team led by researchers from the University of Michigan analyzed the brain waves of mice during sleep and wakefulness. Sensor data were acquired before, during, and after the animals completed the maze task to assess the behavior of neurons outside the maze, such as rest periods.

We achieved this by correlating the activity of each neuron with the activity of all other neurons. The ability to track neurons’ preferences even without any stimulation was a major breakthrough for us.
– says Kamran Diba, an anesthesiologist from the University of Michigan.

The new approach meant that in addition to correlating physical areas of the maze with specific neuronal activity in real time, the team could also work backwards and map neuronal activity to points in the maze while the mice slept.

This was possible thanks to the process of machine learning, which analyzes neurons in their relationships with each other rather than considering them in isolation. Judging by the fact that neurons “fire” during sleep and then again during the next attempt to complete the maze, mice Not only are they imagining places they have previously visited in the maze, they are also working on potential new routes..

These are important results in studies of spatial tuning, that is, how the activity of certain neurons is related to certain locations. This adjustment is a dynamic process and appears to also affect the brain during sleep.

When the mice were released back into the maze after sleeping, neural activity measured while asleep somehow predicted new ways to explore the environment. The matches were not exact, but they were close enough to suggest a connection between dreams and future intentions.

We see the changes that occur during sleep, and when we put the animals back into the environment a second time, we can confirm that these changes do indeed reflect what was learned while the animals were sleeping.
– says neuroscientist Caleb Kemere from Rice University in the USA.

Although this study only involved mice, it is quite possible that something similar occurs in the human brain: a kind of rehearsal for future actions.