Here is the full transcript of professor Dr. Robert Stickgold’s TEDx Talk on Sleep, Memory and Dreams: Fitting the Pieces Together at TEDxRiverCity conference. Dr. Stickgold is the Director of Harvard’s Center for Sleep and Cognition.
This talk is basically about what sleep is doing for us. There’s this common belief that when you are asleep, the brain shuts off, the body lies down and nothing happens. And that’s really not what’s going on. It’s a little bit like a fairy tale, and in fact, “The Elves and the Shoemaker” fairy tale is about my story tonight.
So, here’s the story: The shoemaker was a poor shoemaker, had just enough leather left for one pair of shoes. He cut out the leather for two pairs of shoes – excuse me – and then, as it was late, he left the pieces on the bench, ready to sew in the morning. But when morning came, two pairs of shoes lay on the bench, most beautifully made and no sign of any one who had been there.
What I want to tell you is that this is not a fairy tale. This is what happens for us each and every night. And that sleep, in fact, is sewing together the pieces of our memory. I’m going to walk you through four examples of this, just to show you how powerful it is. I’m going to show you how, when you sleep, your brain will extract from experiences the gist of what happened – it will extract the gist and kind of forget all those details that weren’t so important.
It’ll discover the rules of our lives. It will take large amounts of experiences and take them all together and figure out what the rules are that explain how our worlds work. It will foster insight; it will let us come up with those insights that are so critical and so powerful – and so exciting when we have them.
And dreaming, in fact, is probably part of this entire process, and I’ll show you some new findings that suggest that that’s true. So, let’s start with the idea of sleep extracting the gist. In this study, we had subjects listen to lists of words spoken to them. Imagine you’re in a room – and here are the instructions: you are going to hear a series of words, broken up into lists of about a dozen words each. We want you to remember the words because later on we’ll give you a blank piece of paper and ask you to write down all the words you can remember.
Now, I’ll give you an idea of what that feels like by taking you through one of those lists. Now, there’s going to be a test at the end, okay? And you are going to have to raise your hands. So, I’m going to give you a lesson in medicine. On the back of the arm, there’s a muscle, which is an extensor muscle that makes the arm go out, okay? This is not raising your hand. This is not raising your hand. You have to use that muscle and actually lift your hand because we are doing the experiment now.
Here’s the instructions: Watch these words as they go by. Remember them. You are going to be tested on them. [nurse] [sick] [lawyer] [medicine] [health] [hospital] [dentist] [physician] [ill] [patient] [office] [stethoscope] [cotton] Aaah – that’s not supposed to happen. Okay, end of list.
Normally, subjects would hear about a dozen of these lists and then be tested for recall. They would then come back, maybe twenty minutes later or maybe twelve hours later, and be tested on them. We’re going to do it now. If you saw each of these words, raise your hand, okay? [nurse] If you did see it. Okay? [sick] Lots of yeses. A lot of weak extensor muscles. Okay? Cotton, you see cotton? No, okay, nobody for cotton. [table] I don’t know why that plus is in the middle.