Sleep is one of life's most important things. But if you ask someone what happens during sleep, you'll probably get a blank look. "It's when we recharge," they might say. Or,
"It's when we rest our bodies." These answers are correct—but they don't fully explain why sleep is so critical to our wellbeing. Today, we're going to answer the question: What happens during sleep?
When we fall asleep, our bodies enter a very different state from when we're awake.
When you fall asleep, your body enters a very different state from when you're awake.
The first thing that happens is that your body temperature drops slightly—this can feel a little chilly, especially if the room is warm. Your heart rate slows and breathing slows down as well; blood pressure drops too. Muscles relax and brain activity changes: brain waves slow down while they become more synchronized in frequency (more on this later). If all goes as planned, after about 90 minutes of sleep like this (often referred to as rapid eye movement or REM) your body begins to wake up again—until it's time for bed again!
Our brains visit strange landscapes and experience experiences that aren't possible in waking life.
Sleep is a time for our brains to rest and repair themselves. It's also the time when we experience dreams, which are made up of the stuff of our imagination. While you're dreaming, you can visit strange landscapes and experience experiences that aren't possible in waking life—like flying through space or speaking another language.
You might be surprised to learn that these dreams are actually memories! The hippocampus (a part of your brain) sorts through everything that happens during the day and files away important information as memories in your amygdala (another part). These memories become distorted over time until they're unrecognizable, but still contain enough truth so they feel familiar when you revisit them later on in your dream state.
Scientists are still trying to figure out why sleep is so important.
You know how when you don't get enough sleep, you feel like the whole world is falling apart? Well, scientists are still trying to figure out why sleep is so important. In fact, they've only recently begun to understand that there's something going on during sleep that's not merely passive relaxation—instead it appears that our brains are actually busy doing all kinds of stuff.
Here's what we know so far:
Sleep helps us consolidate memories from the previous day so that we can remember them later
Sleep helps us learn new information and skills for solving problems
Sleep helps keep our brains healthy by clearing out toxins and other waste products from cells in the brain (that’s where Alzheimer’s disease comes from)
Sleep allows for cell repair in the brain and body tissues (which is why athletes often experience injuries after intense workouts)
It regulates hormones throughout your body, including cortisol which tells your body when it should wake up or fall asleep based on sunlight exposure
Sleep is the time for your brain's "housekeeping" tasks, like memory consolidation and cell repair.
Sleep is the time for your brain's "housekeeping" tasks, like memory consolidation and cell repair. It's also when you consolidate memories, form new ones and learn new skills.
While you're asleep, your brain sorts through the information it has collected throughout the day by consolidating memories into long-term storage. This process helps explain why sleep deprivation impairs memory formation (and why heavy alcohol consumption can result in blackouts).
Cell growth and repair occur during sleep as well. During deep sleep, muscles grow and repair themselves with help from proteins that build up during waking hours; meanwhile, cells are repaired throughout all stages of sleep due to increased production of antioxidants such as glutathione.
We've just scratched the surface of sleep here. And it's not just about learning new things—sleep is also essential for our brains to function properly, which means that we need to take care of our sleep needs. If you're having trouble sleeping, check out this guide on how to improve your sleep quality. If there are any other questions or comments you want me to address in future posts on this topic, let me know below!
Comments