Read Full Transcript of Robert Stickgold’s talk titled “Why Do We Dream” at TEDx MarinSalon conference.
From Robert Stickgold Ph.D. Professor and Director of the Harvard Center for Sleep and Cognition and Co-Author of “When Brains Dream”, we learn what dreams are, where they come from, what they mean, and what purpose they may serve.
Robert Stickgold – Ph.D. Professor and Director of the Harvard Center for Sleep and Cognition
Several years ago my friend Barbara told me a dream she had had the night before. This is something of an occupational hazard for me. For the past twenty-five years at Harvard medical school, I’ve made the study of sleep memory and dreams my life work. But if I go to a party and someone asks me what I do, I only mentioned sleep and memory because if I mentioned dreams, the next seven words out of their mouth without exception are, “Oh, I had the most amazing dream.”
And they then proceed to tell me a totally boring dream followed by the question: What do you think it means?
I always give the same answer. I shake my head and I say, “you are one sick cookie.” Then as their expression starts to crumble, I laugh. And I say, “Actually, I have no idea what your dream means and I’m not even sure it does have a meaning.”
The Barbara’s dream was different in it. She told me I was on the street where Stewart per fiance lived. And I was trying to find this apartment because they wanted to settle or not seeing each other anymore. And I couldn’t remember why we weren’t seeing each other. I wonder if I thought I was at his apartment, it’d be somewhere else. And I have to go looking for him again. I kept wondering whatever happened to Stewart in the seconds.
After waking up Barbara asked again, whatever happened to Stewart. And then she remembered two weeks earlier. Steward had had a massive heart attack in her living room and followed him dead in front of her.
Barbara didn’t ask me what her dream meant, but she asked me what I think is the second most common question: “Why did I have that treatment?”
One level, the answer was clear. I knew that dreams had a preference for including recent emotional events, which this definitely had been, but at a deeper level, I couldn’t tell her why the brains algorithms showed this preference for emotional memories. And I had no idea what the brain was actually trying to accomplish despite, but Freud had said 110 years earlier:
Dreams are not about playing out our repressed desires nor as Alan Hopson and Bob McCarley had suggested just 35 years earlier. Our dreams, just the product of the random firing of in our brain STEM.
But What is the brain trying to do?
I knew what it didn’t do. It didn’t show Barbara the memory of Stuart’s collapse and it didn’t let her know. Even that Stuart was dead. All it had let her know was that she wasn’t seeing Stuart anymore and then shown her that without Stewart, she was lost. It was almost as if the brain wanting to see how Barbara, the dreaming Barbara in the dream, how she would react to this situation, what she would do with the knowledge that she was lost without Stewart. And it turns out that is exactly what the brain was trying to do.
My daughter, Jessie, when she was two years old received from her grandpa Irv, an amazing present duck, Mary, in that he made a dance and even fly up, kissing her on the cheek. Jesse loved it. When she went to bed that night, we had to hang ducky on the wall across from her crib.
Later that night, I heard Jessie scream. I ran into her bedroom and found her, standing her crib up on her tip toes, arms outstretched towards me in terror. As I picked her up, she spun around, stared down into her crib and screamed.
There’s a duck in my bed clearly while Jesse slept her brain recalled grandpa Irv and the dancing duck and identified it as an emotionally significant event, but then did what turned it into a real duck and pumped it down in her crib.
What was thinking? Well, just that it didn’t really understand why that duck was so important to Jesse, just sick Barbara’s spring. Didn’t understand the ultimate significance of Stuart’s death to her.
And so both brains dreamed not to deliver messages, not to give answers, but just to explore the significance of these events, because that’s what brains do when they dream.
They sift through and neural networks and code all of our memories, all of our ideas through the 15 billion nerve cells and the 125 trillion connections between them. That’s a thousand times more connections than there are stars in the Milky way.
Nikos through these looking for memories, even weekly related to these events, searching for those that might help us understand them better. They engage in what we call network exploration to understand possibilities or next up for short.
Why do we dream?
Because it’s the only mechanism our brain has for sorting through all the myriad associations of discoveries and deciding which ones are potentially of value are worth strengthening and maintaining. It’s the same as when we’re awake.
My wife, Debbie comes to me and says, what do you think of taking the bowls and plates out of that cabinet, then moving them over there and taking the pasta and yeah. Spaces and moving them where the plates were. I don’t know. So I imagine it first, I imagined the hassle of taking everything out as a one cabinet and moving it to the other and vice versa.
But I’d also imagine grabbing a book for breakfast, which is now right next to the cereal. I imagine cooking dinner and having the spices near at hand. And I react. I like the idea or I don’t like the idea and those feelings, give me the answer to her question. It’s the same.
When we’re dreaming, the brain creates an imagined world out of the associations that it has discovered and punks you down in the middle of it, forcing you to react to the ongoing story. And it looks at those reactions to determine whether the associations that it as built into the story are worth keeping. And if they are right then and there, it strengthens the physical clinic actions between the events of the day and the new associations that is discovered.
Now when brains dream, they have extra tools, extra tricks that it’s disposal that help it find recur associations, more creative ones. We can see these most clearly when we look at the brain in REM sleep, when we have our most vivid, emotional, bizarre dreams:
- First, your brain shuts off output from the hippocampus, a region of your brain required for the detailed recall of recent memories. So you can’t replay actual memories in your dreams.
- Next, it shuts off its release of the neuromodulator noradrenaline, which leads to a bias for finding weaker associations.
- Then it almost completely shuts down regions, your forebrain brain responsible for logical reasoning and impulse control regions that otherwise might prevent these unlikely dream scenarios from ever getting imagined.
- And finally, it cranks up your limbic system, increasing the intensity of your emotional responses taken as a whole.
These tricks allow our brains to explore, identify and strengthen previously unnoticed associations that can help us better understand both what has happened to us in the past and what might happen to us in the future.
Let me end with a dream of my own. Hopefully not a boring one:
When Jesse was five years old, I was hired as an assistant professor in the department of physiology. The university of Massachusetts medical center. One of my responsibilities was to co-teach the introductory physiology course along with its lab component.
One lab was notoriously known as the dog lab. When students arrived, they found anesthetized dogs on benches and were assigned to one of the dogs where they would spend the next couple of hours, injecting drugs, monitoring heart rate, monitoring, blood pressure, and doing other only slightly invasive experiments on the dogs.
But then they would get to the final portion of the lab, where they had to take a small buzzsaw and cut through the rib cage and open the chest so they could apply drugs and do recordings directly from the heart.
It was a gruesome process and frankly, I couldn’t cope with it. I would always turn my group over to one of the other faculty members to supervise them as they opened the chest. The night after I first taught the lab, I had a dream. We had just cut open the chest of the dog when I looked down and saw not in horror, but in confusion over how it had happened, that it was Jesse and not a dog.
And then as I watched the edges of the incision, came back together and healed without any scar at all. When I woke up and told my wife, she said, well, that makes sense. The lab obviously brought up issues of mortality. And where are you most fearful about mortality, except for Jesse.
This made sense to me, but it didn’t match my own gut feelings. To me, it seemed that the dream was saying, if this is okay to do to a dog, why isn’t okay to do to Jesse? Well, we now know that neither of these was the meaning of the dream.
My brain had identified the event as extremely emotional and had sought out memories related to it and found another small, helpless creature, Jesse, and then put them together in the dream to explore possibilities, maybe finding something about the fragility or the sanctity of life. And that’s all my brain was doing, exploring possibilities, strengthening those connections and leaving that newly found association available for my youth in the future. That’s all brains do.
When they dream use later, my son, Adam was born with a congenital heart defect. And so at four months of age, he underwent open-heart surgery to patch a hole in his heart.
They cut through his chest wall, repaired his heart, and then sewed him back together today. He’s a vibrant athletic pain in the ass, 16 year old with almost no scar at all. It was so tempting to believe that my dreaming brain had looked forward into the future to warn me of what was to come.
But no I’m convinced that’s not what happened. It was in fact, just one of those coincidences that we all have that are so hard to shake, especially when they occur in a dream. When we dream our brain is in a unique neurophysiological and neurochemical state that not only facilitates the discovery of weak associations, but also biases that bring towards finding significance importance in those associations and importance that carries over for at least a few minutes after we wake up giving us that sense of create meaning. So now it was next up.
I think we finally know the function of dreaming. We know why we dream dreaming brain serves as a mechanism to identify, explore, and evaluate unexpected associations within our memory systems that might help us better understand what has happened to us and what is going to happen with us, but for all that science has, and we’ll discover about the meaning and function of dreams. They’re magic. They’re mystery. They’re wonder will remain. Thank you.
– Robert Stickgold
Robert Stickgold’s talk titled “Why Do We Dream” at TEDx MarinSalon conference: