We spend a third of our lives sleeping, an activity as crucial to our health and well-being as eating.
But exactly why we need sleep hasn’t always been clear. We know that sleep makes us feel more energized and improves our mood, but what’s really happening in the brain and body when we’re at rest?
Here are five incredible things your brain does while you’re asleep
The brain can process information and prepare for actions during sleep, effectively making decisions while unconscious, new research has found.
A recent study published in the journal Current Biology found that the brain processes complex stimuli during sleep, and uses this information to make decisions while awake.
Creates and consolidates memories
While you’re asleep, the brain is busy forming new memories, consolidating older ones, and linking more recent with earlier memories, during both REM and non-REM sleep. Lack of rest could have a significant affect the hippocampus, an area of the brain involved in memory creation and consolidation.
For this reason, sleep plays a very important role in learning — it helps us to cement the new information we’re taking in for better later recall.
Makes creative connections
Sleep can be a powerful creativity-booster, as the mind in an unconscious resting state can make surprising new connections that it perhaps wouldn’t have made in a waking state.
Clears out toxins
A series of 2013 studies found that an important function of sleep may be to give the brain a chance to do a little housekeeping.
If we’re not getting enough sleep, our brains don’t have adequate time to clear out toxins, which could potentially have the effect of accelerating neurodegenerative diseases like Parkinson’s and Alzheimer’s.
Learns and remembers how to perform physical tasks
The brain stores information into long-term memory through something known as sleep spindles, short bursts of brain waves at strong frequencies that occur during REM sleep.
This process can be particularly helpful for storing information related to motor tasks, like driving, swinging a tennis racquet or practicing a new dance move, so that these tasks become automatic. What happens during REM sleep is that the brain transfers short-term memories stored in the motor cortex to the temporal lobe, where they become long-term memories.
“Practice during sleep is essential for later performance,” James B. Maas, a sleep scientist at Cornell University, told the American Psychological Association. “If you want to improve your golf game, sleep longer.”