Brain predicts and plans for future events during sleep, study finds

The neurons functioning inside the brain's memory area when we sleep may be doing more than just recalling prior events. According to a new study, they may also prepare for future events.

A team of researchers from the University of Michigan examined brain wave measurements from rats throughout periods of awake and sleep. Readings were obtained before, during, and after the animals completed maze trials to assess nerve cell preferences outside the maze, such as during rest intervals.

"We addressed this challenge by relating the activity of each neuron to the activity of all the other neurons. The ability to track the preferences of neurons even without a stimulus was an important breakthrough for us," says anesthesiologist Kamran Diba, from the University of Michigan.

Add WION as a Preferred Source

The innovative technique allowed the scientists to not only correlate actual areas in the maze to particular neuron activity in real-time but also work backward and map neuron activity to spots in the maze while the rats were sleeping.

The rats were not only dreaming about locations they had already explored in the maze but also brainstorming possible new pathways, based on the neurons firing during sleep and again during the subsequent maze try.

These are key results in the research of spatial tuning, which is the relationship between the activity of certain neurons and specific places. This tuning is a dynamic process, and the sleeping brain appears to be involved.

When the rats returned to the maze after resting, the brain activity recorded during their slumber predicted the new ways they explored their environment. While the matches were not precise, they were near enough to suggest that dreams and future intentions are related.

Sleep has long been known to aid in memory formation, and while this study only looked at rats, something similar is probably happening in human brains, a type of rehearsal for future events.