The Power of the Downstate summary

Every night, while you’re sleeping, a strange thing happens inside your brain.

Picture your head as a concert hall filled with about 86 billion tiny musicians. These are your neurons – the cells that make up your brain. Like an orchestra, they’re organized into different sections, which are usually playing different melodies at different times. The notes are the electrical and chemical signals they send to each other, which can be measured as brain waves. When you’re awake, these notes tend to play at a rapid tempo, creating brain waves that vibrate at 13 to 25 or more cycles per second (or hertz, to use the technical term).

But during a stage of sleep called slow-wave sleep, they go all the way down into the range of 0 to 4 hertz. Not only that, they stop playing separately, and they all start playing the same note in unison. For half a second, they fire their signals at once. This is called an upstate. Then, for another half a second, they stop – the orchestra goes silent. And this is called a downstate.

At this moment, your brain enters a place of pure tranquility. All is quiet. All is still.

Sound refreshing? Well, it is. In fact, as you'll learn in more detail later, it’s the secret to why a good night’s sleep is so revitalizing. But it’s also kind of creepy, because, during that half second of inactivity, your brain is basically dead.

Fortunately, it doesn’t stay that way for long. After the half second of silence has ended, your neurons return to the upstate and fire off their signals in unison again. Then they go back to the downstate, they stop firing, and they keep repeating the same pattern over and over – on and off, on and off.

Now, the weird thing about slow-wave sleep is how your neurons all turn on and off in unison, on the other hand, it’s completely normal for them to turn on and off at separate moments. They do that all the time, throughout the day and night. And they do it because neurons are just like us: they need to work, but they also need some downtime.

In fact, they need to take a break after every round of sending messages. And that’s because they lose their electrical charge whenever they fire their signals, and they need some time to recharge themselves before they can do it again.

A similar pattern governs many systems of your body – from your cardiovascular and autonomic nervous system to your metabolism and circadian rhythm. Each of them follows the same basic playbook: build up resources, energy, and strength, use them to get something done, and then take some downtime to replenish them and be able to do things again.

To provide us with some vocabulary for describing this pattern, the author borrows the terms “upstate” and “downstate” from neuroscience. For example, imagine one of your body systems is expending itself? Then we can say it’s in an upstate or doing an upstate activity. And then, if it’s restoring itself, we can say it’s in a downstate or doing a downstate activity.

Your body has various downstate systems and processes for revitalizing itself. By tapping into them, you can reap the benefits: more energy, less stress, and better physical and mental health. So what are these systems and how can you take advantage of them? That’s what the rest of this Blink will explain.