UCI Podcast: The perils and benefits of dream incubation

When the sleeping mind hears certain sounds or smells certain odors, the landscape of dreams shifts. Some memories are reinforced, while others grow dim. By manipulating sounds and smells, scientists and corporations are able to influence our dreams and thus our waking lives.

What are the dangers — and benefits — of this kind of targeted dream incubation? And how do our dreaming hours keep us healthy?

From the University of California, Irvine, I’m Aaron Orlowski and you’re listening to the UCI Podcast. Today, I’m speaking with Sara Mednick, a professor of cognitive neuroscience at UCI.

Professor Mednick, thank you for joining me today on the UCI Podcast.

Thanks for having me, Aaron

So you, along with about 40 other sleep and dream scientists, recently signed an open letter raising some alarms about a new type of advertising called “targeted dream incubation.” Listeners might have heard of this because Molson Coors, the beer company, generated a lot of headlines about this back in January and February when they announced a plan to use this advertising method around the Super Bowl. So I want to ask you: What is dream incubation and how does it work?

The first thing to kind of understand is that sleep is a time when we are processing our recent experiences and we’re folding them away and putting them into long-term storage areas where they can be safe and not overwritten by the next day’s experiences. The idea that you could kind of interfere with this memory processing time or this sleep time has been talked about for a century, at least. But it wasn’t until about 15 years ago, 10 years ago, when researchers realized that if you pair the thing that you want to remember with a specific sound while you’re trying to learn it.

So if you’re trying to learn the position of a lot of different objects and where they go in a puzzle and each puzzle piece has an object’s face on it like a cat or a tea kettle or a dog or a car. And all of these objects have a specific sound. The cat sounds like a “meow” and the dog sounds like a “ruff,” right? And every time you place that cat puzzle piece in the specific position it goes into the puzzle, you hear the “meow” sound. So you tie that sound to that position in the puzzle. When you then go to sleep, you play the “meow” sound, right? And you play — say, maybe there’s a hundred puzzle pieces. Maybe you play only 50 of those puzzle pieces. And then you wake up the next day and you see how many of those puzzle pieces do you remember their location? It turns out that those sounds that you played in the middle of the night, biased that memory processing to actually only focus on the puzzle pieces that had the sound played. It reactivated specific memories, and it made the memory process focus on only those memories.

And so what happens is your performance for just the memories that you reactivated during sleep. Well, Coors decided that they could use this idea in order to make you have an association between the Coors beer and very specific sounds that were the sounds of a mountain stream or birds chirping or beautiful like very refreshing feelings and sounds. And then when they went to sleep, the subjects were played those sounds again, and woken up, right after they were probably dreaming for awhile with those sounds in their heads. And they asked them, well, what were you dreaming about? And they were dreaming about Coors.

Wow. So this could work for any variety of objects or subjects or … ?

Yeah, anything you can pair a sound to. But it doesn’t just have to be a sound. It could be a smell. If there was a specific thing that you wanted somebody to associate, we could use targeted memory reactivation, where we target specific memories to be reactivated during sleep. And we can increase people’s memories. But it’s also been shown that we can actually make people forget certain memories by doing this targeted memory reactivation. So it’s like a targeted forgetting, very similar to the “Spotless Mind” movie, where people were trying to take out memories of long lost loves that they missed, their heartbreaks. And you could actually take out that memory. Well, this is exactly that idea that you can actually during sleep, instead of remember things more, you can actually delete things.

That is crazy. And the movie “Eternal Sunshine of the Spotless Mind” was quite trippy. And if I remember the characters wanted to reverse their forgetting in the end.

Yeah. It’s, I mean, there’s just a whole bunch of potential things that it can be used for, that some of them are really great. There’s beautiful research looking at people who are smokers who want to stop smoking. And during sleep, they send in the smell of cigarette smoke into the noses of the sleeping subjects. And at the same time, they pair that smoke with the smell of rotting fish. And what they find is that that creates a negative association with the smoking. And when people wake up in the morning, they don’t want to smoke.

So this sort of dream manipulation and memory adjustment, can be used for different purposes, helping an addict overcome their smoking addiction. But also we just talked about Coors using it to encourage people to want to drink more beer. So why are you concerned about this method being used by corporations?

You know, back in the day before we knew about subliminal messaging manipulating people unconsciously to buy products, there was a lot of advertisements that were sent very quickly through films and you couldn’t even see them and suddenly you’ve got the urge to drink Coke, you know, or eat more popcorn, or whatever it was. And that was outlawed because it’s unfair. It’s unfair that people unconsciously are being driven to do things that they don’t even realize that they’re being manipulated to do. So that’s, that’s that that’s been regulated by this point. And those rules only really actually applied to waking experience. And the thing about the law is that you need to actually be very specific or people will get around it. You need to really say, okay, you can’t do the subliminal messaging, either in wake or sleep.

And particularly because sleep, you’re actually even more vulnerable to messaging than you are during wake, because you’re sleeping. You don’t remember anything. Subjects never remember that they had sounds played or smells played. And so you have no sense of when you’re being manipulated or not. The Nest system has an algorithm that knows when people are sleeping in that room. And if that’s the case, then they could also play music, they can play whatever sounds that they want. And so it’s not a far shot to say that if you know when someone’s asleep, you can add information into their sleep that would be unbeknownst to them.

Well, so we’ve been talking a lot about the potential nefarious uses of this type of messaging in people’s dreams, but maybe we can talk a little bit more about why people dream in the first place. What function does it serve for people to have dreams?

It’s a great question. And if you find out the answer, I hope I’m the first person that you tell. Nobody knows. We’ve been trying to figure out this question for centuries. And it’s one of the earliest questions known to man and woman, because we’ve always dreamed. Evolution hasn’t pushed it away and we still dream. And we still don’t know why. There’s many hypotheses. You know, I’m a cognitive scientist, so I look, maybe those dreams that are helping you rehearse the information that you just learned during the day. And that may help you with that long-term storage mechanism I was talking about.

You know, dreams also have emotional content to them. And so there’s an idea that while you’re dreaming, you’re actually rehearsing and playing out certain kinds of scenarios. Maybe you’re saying, well, what would I do if an ax murderer was running after me? Like, hmm, let me see that again — you know, like these recurring nightmares. Like, what would I do in this case where somebody dumps me or whatever it is. And so you have these kinds of recurrent scenarios in your mind to see, like, what are different potential strategies and outcomes that I could choose?

At the neuroscience level, the idea is that with emotional experiences, we are uncoupling the emotional areas of the brain from the memory areas. And over time, these experiences that are at first rather really emotional actually become less emotionally charged and more kind of cognitively charged, where we can start to think about them a little more rationally over time. And that’s a very natural process that happens with emotional experiences and it requires sleep to have a natural progression such that, you know, eventually that breakup that you thought you’d never recover from in a month, you’re like, yeah, all right, well, I did this wrong or, you know, she did that wrong, or whatever it was that you want to say.

Yeah. Unless you’re in “Eternal Sunshine of the Spotless Mind,” in which case you just regret it eternally,

And then you just keep making the same mistakes over and over and over.

Yeah. Well, so it sounds like sleeping and dreaming essentially helps us heal. So how does our mood change after we’ve slept or after we’ve dreamed?

There’s obviously the idea of sleep on it you’ll feel better in the morning. And it turns out that sleep may help you feel worse in the short term and better in the long-term. And you could imagine why, right? If something happened to you while you were walking home, you know, you decided to take the darker route home, and something happened to you, you don’t want to just forget that thing. It’s actually really protective to have a strong, emotional response to a negative experience. And what has happened is you actually have a stronger emotional response right after you wake up in those first few days. You’re really living inside that emotional response. And then over time that emotional response starts to waiver or just decrease. And what you get is this stronger and stronger cognitive response. Those are really natural protective mechanisms that teach us not to do these things that didn’t work out anymore.

Yeah. Well, you mentioned earlier that we are especially vulnerable to messaging while we’re asleep and, and more so than when we’re waking. And I guess on one level that seems kind of intuitive, but can you tell us more about why that’s the case?

Many people wake up and they have no idea what they dreamed, right? Your hippocampus is a brain area that takes in new information. And sometimes it’s, it’s on, a of the times it’s on during sleep, but the part of the brain that really connects to the long-term memory and to really storage and to holding on the information, is also the frontal cortex. And the frontal cortex when you’re sleeping is totally turned off. So you may have this connections to what recently happened and then what happened 10 years ago to you, and you have these dreams that are making wild connections between all these different experiences and that recent thing that just happened to you.

But when you wake up in the morning, you don’t remember any of these things. And that’s probably a good idea, right? Because you really want to focus on the things that are “real.” And the dream time may be some subconscious practice that you’re getting through, some process that you’re working through. But you don’t want to hold onto your dreams per se, more than your waking life. So it’s actually sort of evolutionarily better to not necessarily be carrying your dreams around all day, but that also means that you don’t know what happened to you in the middle of the night, if your dreams were suddenly full of Coors commercials.

Yeah. You might not know how that got there, how those arrived.

Yeah, you definitely wouldn’t.

Yeah, well, and I want to ask you one final thing. If I just want to get good sleep, what steps should I take? You’ve studied many people or many components of sleeping and how to increase quality sleep. So what are the best actions to take?

There’s so many different things that can be done. And there’s a whole list of — any website will tell you what sleep hygiene tips to take. But some of the ones that don’t necessarily get recommended, but I recommend is getting to sleep early. Because the sleep that you get in the first part of the night is different than the sleep that you get in the morning. So the idea that you can get to sleep late and then sleep a little bit later in the morning, you’re not actually getting the sleep that’s the really good sleep. What’s called slow-wave sleep happens in the first part of the night. And that’s the stuff that does all the clearance of toxins from the brain. And when people get older, they have less and less slow-wave sleep and more and more buildup of these toxins that can lead to the plaques that develop with Alzheimer’s. And also a lot of this memory consolidation stuff that we’ve been talking about all happens during slow-wave sleep. So really getting to sleep early, I’m talking like 10 p.m., is very important for getting that early deep sleep that is the most restorative that we have.

Another thing is to make sure that when you wake up in the morning, you go outside and you get some sun. We are rhythmic animals and the sun is the strongest what’s called entrainer, basically. It’s the downbeat for our day. And when you get bright light early in the morning, that sets you up to actually be ready for sleep at night. And if you don’t have bright light, maybe it’s the winter time and you’re on the East Coast or something, get one of these really strong all spectrum lights and just have it for 15 minutes on while you’re having your breakfast in the morning. I could go on and on, but reduce blue screens after 6 p.m. The blue light is really strong inhibitors of melatonin, which is a sleep hormone. And so you want to make sure that after 6 p.m., you’re really trying not to get in front of any fluorescent lights or any lights that don’t have some filters on them.

Professor Mednick, thank you so much for joining me today on the UCI Podcast.

Thanks for having me. It was super fun.