I once spoke to my sister (insert triumphant music). And as the script usually goes, she spoke back to me (more music). It lasted 60, maybe 90 seconds (fanfare now).
It was late, really late, and there I was coming up the hall, ready to take the right turn to my room and the bed when I heard her. Being inquisitive, concerned for her, thinking she needed something and I could help, and hoping to hear something funny I could totally embellish the next day, I continued straight on into her room, standing casually on the rug while we conversed.
She talked. I responded. We talked some more. It seemed to me to be a rational conversation. Which wasn’t bad, considering she was asleep at the time.
If you’ve ever been a bit spooked by a cow sleeping with its eyes open (I’ve stopped talking about my sister now), you know already that there are different ways to go to sleep, and that sleep isn’t just a time when nothing happens, see above. Sleep is common to all mammals and, while it may differ in terms of how much sleep we get each day, and how we fall asleep, it is universal, and we must have it.
You know already that we progress through a predictable process of sleep. We have a number of sleep cycles a night each lasting about 90 minutes. Each cycle comprises a number of stages. Overnight, you’ll progress like this
- Stage 1 NREM
- Stage 2 NREM
- Stage 3 NREM
- Stage 2 NREM
- Repeat x 5
Animals have similar stages too. Behind the stages is some pretty impressive machinery to help us sleep. While it’s easy to think of sleep as a general slowing down, where we don’t do much, it’s not quite so simple for the brain. During this time, a number of things happen, and in order for us to actually get to sleep, there are two critical processes that must align:
Now for the most part, we can usually tell, just by looking, when someone is awake or asleep – unless they’re in politics and then it can be tough. However, because we now know that there are different stages, we have to have a way of finding out what’s happening, and of differentiating one stage from another. Here’s how it’s been done.
Brainwaves and brain bits
Each sleep stage has characteristic brainwaves, which are electrical. To measure these, we use a machine called an EEG, or electroencephalogram, which measures (-gram) the electrical (electro-) output of the brain (encephalo-). EEG is just easier to say, and it’s not to be confused with the ECG which is the same thing for your heart, where the C stands for cardio. This has allowed us to dig a little deeper into what’s going on while we sleep, so let’s get to some of the detail
Sleep, as a thing that we do, occurs naturally, no training required. Sleep habits might need training but sleep? We just know how to do it. While asleep we don’t seem to achieve much, we show a distinct lack of consciousness and we’re pretty unresponsive to things around us.
Wakefulness is a natural state too, but it’s characterized by activity, consciousness and responsiveness to external things. When we’re awake, we show a characteristic brain wave pattern of high frequency brain waves. Wakefulness itself is controlled by a region in the brainstem, which is located at the top of your neck, where your spinal cord meets your brain. A bunch of chemical pathways begin here, and move like tentacles to a number of different parts of your brain. It’s the activation of these pathways that trigger wakefulness.
When it comes to sleep, we already know one key factor, and that’s our daily rhythm, our circadian rhythm. The other key factor in sleep is how long it’s been since we last had a sleep.
Here’s an example
Let’s say you’re getting pretty decent sleep, and you normally rise about 6.30am. By 8.30am you’re in full swing and, for the next couple of hours, capable of performing some of the most complex mental tasks of the day. This is a really high functioning time. So what happens if, during this time, you decide to go to bed? Chances are, you won’t sleep. First, you’re way out of sync with your rhythm and, secondly, it hasn’t been long enough since your last sleep.
But at night, when you’re nearing 16 hours since your last sleep, you’re beginning to get ready for some more.
The Boss needs the report you’ve been working on by 8.30am! Aided by caffeine, sugar and quick music you slog it out all night. The longer you go without sleep, the greater is the pull of the pillow, because your brain needs a regular amount to get by. And when you finally get there, you’re likely to have a REM rebound, where you’ll have greater than normal REM sleep to make up for the sleep you lost. Next post we’ll cover sleep deprivation in more depth.
So here’s the take home bit
So the brain will activate the sleepiness programme when it needs to, or when it can, paying attention to the time of the last sleep and our natural daily cycle, altering our brainwave pattern as we drop into sleep. At the right time, it will then begin the chemical system that causes wakefulness.
While we can from time to time mix it up a little, the brain knows full well when it’s ready to get some sleep and what it needs to do. It wants us to play ball. That means giving it what it wants because, sure as anything, it will get sleep, or we will pay for it!
So the number one take home is simple. Work with the system rather than against it.
Keep sleep regular. This, pretty much more than anything, is one of the best things you can do.
Impressive words to drop into the morning coffee chat
What’s it like for you?
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