A growing collection of research confirms just how important sleep is to our health, and the extensive benefits include a healthier heart and reduced levels of stress and inflammation. In a new study, researchers have discovered that sleep is what gives us the brain capacity to continue learning throughout the course of our lifetime.
Experts in the UC San Diego School of Medicine used computational models to simulate the brain during various states. The researchers investigated how sleep consolidates new memories and prevents damage to old memories.
“The brain is very busy when we sleep, repeating what we have learned during the day. Sleep helps reorganize memories and presents them in the most efficient way,” said study lead author Dr. Maksim Bazhenov. “Our findings suggest that memories are dynamic, not static. In other words, memories, even old memories, are not final. Sleep constantly updates them.”
“We predict that during the sleep cycle, both old and new memories are spontaneously replayed, which prevents forgetting and increases recall performance.”
Dr. Bazhenov said that memory replay during sleep plays a protective role against forgetting by allowing the same populations of neurons to store multiple interfering memories.
“We learn many new things on a daily basis and those memories compete with old memories. To accommodate all memories, we need sleep.”
“When you play tennis, you have a certain muscle memory. If you then learn how to play golf, you have to learn how to move the same muscles in a different way. Sleep makes sure that learning golf does not erase how to play tennis and makes it possible for different memories to coexist in the brain.”
According to the study authors, the restorative value of sleep may be what is lacking in current state-of-the-art computer systems that recognize images with incredible speed and accuracy. These artificial intelligence systems lack the ability to learn continuously, and old knowledge is forgotten when new information is learned.
“We may need to add a sleep-like state to computer and robotic systems to prevent forgetting after new learning and to make them able to learn continuously.”
Dr. Bazhenov said the study results could lead to developing new stimulation techniques during sleep to improve memory and learning, which could be particularly beneficial for older adults or people with learning disabilities.
“While sleep is certainly involved in many important brain and body functions, it may be critical for making possible what we call human intelligence – the ability to learn continuously from experience, to create new knowledge and to adapt as the world changes around us,” said Dr. Bazhenov.
The study is published in the journal eLife.