Your Brain Has a Night Shift
In the last post, we left you unconscious. This seemed a little rude, but it was necessary. You had spent the day learning things, making decisions, dealing with people and solving problems. Basically, you and life had given your developing brain a large pile of new experiences to deal with. Then you went to sleep. Your brain did not. This is when some of its most important work gets started. Your brain begins sorting through what you learned that day, organizing it and connecting new learning with things you already know. Then it strengthens those new connections so that learning becomes a memory you can use again. Sleep might look like hours of absolutely nothing happening. You are just lying there… sleeping. Your eyes are closed. You are contributing very little to the conversation. But inside your brain, important work is underway.
Sleep is a critical part of making new learning last. Disturb sleep enough and some of that learning is lost. And learning is only part of the story. How well you sleep tonight also affects how well your brain handles attention, decisions and emotions tomorrow.
What Happened to Today?
You learned something new in class today, and maybe you realized (that is, learned) something about interacting with friends too. When you learn something new, a brain structure called the hippocampus temporarily holds the new learning or memory. What you learn today and is held in the hippocampus is initially fragile and temporary. Think about how much new information and experience arrived in just one day. Something your teacher explained. A new skill you tried. A conversation. Something you suddenly figured out about a friend. The hippocampus does a hippo of a job, creating up to 10,000 new neurons each day and capturing a lot of new stuff. Now, not everything from today will be kept. But, the important stuff you want to remember needs your help. It needs sleep.
During sleep, your brain is just getting started on its most important learning work!
It processes and organizes what you learned that day. It strengthens connections to important new learning so it lasts and is there when you need it again. This matters when learning a skill too. You practise a guitar chord, basketball move or dance sequence that initially feels impossible. Your fingers or feet appear to have resigned from the project. You practise, then sleep, and that gives your brain time to work with that new learning. Sleep… It is critical to learning.
Tomorrow Arrives
Suppose two versions of you arrive at school. One slept well. The other was awake much too late and has now been separated from their bed against their wishes. Both encounter the same annoying situation. The well-rested brain still gets irritated. Sleep does not transform anyone into a permanently peaceful mountain monk. But after too little sleep, attention, decision-making and emotional control become more difficult. Frustration arrives faster. Concentrating takes more effort. An ordinary problem suddenly feels considerably larger.
The situation did not necessarily change. The conditions inside the brain trying to handle it did.
Your developing prefrontal cortex helps with attention, planning, decisions and controlling behaviour. Sleep supports how well those abilities work the next day. That makes sleep important not only for learning, but also for mental well-being.
There Is One Slight Problem
During adolescence, yet another thing to deal with, the body's internal timing naturally begins shifting. Many teenagers don’t start feeling sleepy until later at night. That is partly biology, not simply teenager-you collectively deciding bedtime is unreasonable. Unfortunately, morning did not receive the same memo. School still starts. Add homework, friends, entertainment and a device capable of producing something new every three seconds, and sleep gets squeezed. Squeezed hard. Repeatedly getting too little sleep greatly affects learning, attention, mood and emotional control. One late night has not ruined your brain. The repeated pattern over time matters much more.
The Night Shift Matters
Think back to the brain from our first post. It is developing while handling new experiences, greater independence, changing relationships, social comparison and increasingly complicated decisions. All day long, that brain is being asked to learn.
Sleep is part of the conditions that support that learning.
So sleep is not simply the empty space between today and tomorrow. Your sleeping brain is processing information and supporting memory while other systems recover and prepare to function again. Tomorrow's attention, learning and emotional regulation partly depend on what happened overnight. And tomorrow will almost certainly provide something that requires all three. Especially if somebody replies: “K.”
Vocabulary
- Hippocampus: The part of your brain that temporarily holds new learning and memories. It also has an important role in how you feel.
- Neurons: Brain cells that connect with other brain cells to hold and use learning.
- Prefrontal cortex: The growing part of your brain that helps you plan, control impulses and make better decisions as you learn and mature.