Here is the full transcript of sleep researcher Sara Mednick’s TEDx Talk: Give it Up for the Down State – Sleep at TEDxUCRSalon.
Listen to the MP3 Audio here: Give it Up for the Down State – Sleep- Sara Mednick at TEDxUCRSalon
Hello. Okay, well, I’m going to tell you something you’re not going to like, I’m sorry.
Well, actually, part of you is going to really like it and say, “God please, listen to this lady!”
And the other part is going to say, “Ah, ah, not me!”
And it’s this. Are you ready?
We need to rest. We need to take more breaks. Because, you see, taking breaks is actually part of life. It’s part of being active, it’s part of being productive and having endurance, it’s part of being creative, it’s part of being happy.
So what I hope to convince you about today in this talk is that you should be taking breaks on a daily basis, on a weekly basis, on a yearly basis, and if you do, you’ll be a better person.
Okay. So we need to take breaks. But it’s not just you. Every person, every plant and animal on this earth needs to take breaks.
And here’s why. Here’s the Earth spinning on its axis. Imagine, every day we get the night and the day from the Earth spinning on its axis. It tells us when to be up in this upstate, where we get to go out in the world and explore and find our riches, and then the downstate, right, the nighttime, we get to go home, check all these things out and then go to sleep and dream about them. This happens every day.
That’s every plant and animal on the surface of the Earth for 4.54 billion years uses this cycle. That’s 1.65 trillion nights!
And here’s a secret about life. If something happens every day, since the beginning of time, it’s probably important. You might want to think about it.
So we all sleep, right? Nighttime tells us when we should be sleeping, and we all sleep. So doctors, lawyers, babies, even President Obama sleeps, hopefully.
And so what do we sleep for?
Well, science shows us that sleep is very important for restoring our basic functions. And they know this by looking at people who aren’t sleeping. People who aren’t sleeping – they have messed up metabolism and their insulin regulation is messed up.
And what does that do?
Well, it makes them reach for more high fat, high sugary foods. It makes them gain weight more quickly. And even with 5 nights of sleeping, say even 5 hours at night, you start looking like you are pre-diabetic. So, if you think about the epidemic of obesity and diabetes in this country, maybe we should also be thinking about how people sleep.
So along with these problems with metabolism, not sleeping enough also creates larger risks for cardiovascular disease, depression and impaired cognition.
Okay, so a lot of you might be saying, well, some of you might be saying, “Well, you know Sara, I sleep fine, I get like 7 to 8 hours of sleep at night.”
And to you, the few, the proud, the well-rested, I have this to say, “Listen to this next part, this might be more relevant to you.”
So, in my lab we decided to look into: Well, how do people who are well rested actually deal with just being awake all day long?
So we brought people into the lab and we tested them for 4 times in 1 day on a really simple visual memory task. And what you see here is the graph of their results. We tested them at 9, noon, 4 and 7. And as you can see, their performance continued to decline. Across each day, with every test session they got worse and worse.
The astonishing thing about this result is that we tried several different methods to get them to actually get their performance back to their baseline. So in one case we told them, “Well, we’ll give you some money,” because that’s a big motivator, right?
We say, “We’ll give you $25 for every test session you could get just back to your baseline.”
Well, sadly for these subjects we didn’t have to give them a single dime, because they couldn’t get their performance back to baseline. We thought, “Okay, well, motivation didn’t work; what about just letting them take a little break by just resting quietly?” So, we had them sitting with their eyes closed between noon and 4. And these people still, their performance just declined.
So what was the one thing we did that got them to actually get their performance back to baseline? It was taking a nap.
So when we gave a nap in between noon and 4, just about a 60 minute nap. What happened? Their performance went back to baseline and it stayed there for the next two sessions. So we thought, that’s pretty surprising, right? This little nap in the middle of the day could make you maintain your performance across the day.
So we decided to replicate this. But this time we just tested people twice, at 9 and 7. So here is people’s performance at 7 pm if they didn’t nap. And here is people’s performance at 7 pm if they did nap. And as you can see, their performance actually went back to baseline and even exceeded baseline, so they actually showed perceptual learning, they showed improvement in performance.
So we were pretty surprised by this and we thought, “Okay, well, let’s just compare that to people who have a whole night of sleep, maybe they are going to show even more”.
And as you can see, a night of sleep is the same as a daytime nap in terms of this performance. People are actually getting the same benefit from a nap as a night of sleep.
So we thought, okay, well, we should test this across a bunch of different memory domains and a bunch of cognitive domains, and we showed the same result. In one case we looked at creativity. The reason why we did this is because many creative people have said that they had gained an insight into a problem that they were having during sleep. Such as Paul McCartney wrote “Yesterday”, Mary Shelley wrote “Frankenstein”, Frederic Kekule actually designed the benzene ring in his dream.
Okay. So, we thought, well, we’ll take people, bring them into the lab, give them a creativity test in the morning, and then either have them have a nap or no nap in the afternoon, and then retest them again in the evening.
So here’s the result. As you can see, when you had no nap you don’t have a change in your creativity. But when you have a nap, you have a 40% increase in your creativity.
So what’s going on? What’s happening here in the brain that you can actually have such increases in memory and heightened creativity?
Well, the thing to think about is that during sleep your brain can do things that it just can’t do during waking. Because during waking we are constantly bombarded with new information. On a moment to moment basis we have to interact with the world. But when we sleep, we turn off the external world, we go internal. We start to repair our tissue and bone, we promote growth. We start to protect all of those new memories that we just learned and consolidate them into long-term memory.