Can you communicate with someone who’s sound asleep, and is it possible to influence their dreams? Dr. Ken Paller, professor of psychology at Northwestern and a leading sleep researcher, talks about “lucid dreaming” – the state of dreaming while knowing you’re in a dream – as well as about how researchers can reach into the brain of a sleeping person and actually create the experience they have in their dreams. Is it ethical to influence the dream state – and what are the implications for brain health if we can never turn off?
Phil Stieg: Hello and welcome to Professor Ken Paller, director of the Cognitive Neuroscience Program at Northwestern University. We spend up to one third of our lives sleeping. Many biological and physiological functions occur during sleep. One of these, dreaming, has taken on new significance through research by Dr. Paller. Today, we will explore the importance of sleep cycles, how learning may be facilitated during sleep, and importantly, how these techniques might be used to treat bad habits such as smoking or other clinical issues like anxiety and PTSD, as well as preserving memories or speeding up the acquisition of new knowledge. Dr. Paller, thank you and welcome to This Is Your Brain.
Ken Paller: Good to be with you, Phil.
Phil Steig: I find it interesting that you describe sleep as a complex symphony and then reading through your material, I understand why. Can you explain what symphony is going on in our brains while we’re sleeping?
Ken Paller: Maybe the first step is that the brain is actually working during the night because we think about sleep as a time for relaxation, for our muscles to take a break, and for our brain to take a break because it seems like we’re unconscious. But no, the brain is “on” all night and busy, and to make sense of it is difficult, of course, because we have limited methods and we record, for example, the EEG signals which have all these different frequencies. So in that sense, perhaps it’s like a symphony because there are many different frequencies, many different types of activity going on in different brain areas. And we’re working hard to make sense of that and understand what it means. What’s happening in the brain during sleep.
Phil Stieg: Yeah, I think it’s important for people to understand that there’s sleep cycles and then there’s durations of these cycles. Can you explain to us what the normal sleep cycle is and how long each one of those might last?
Ken Paller: Sure. And it’s pretty interesting that humanity has had this habit of sleeping forever, but we didn’t really know much about it if we only had our first-person perspective. So you wake up, you may feel rested, you may remember a dream, but you don’t know the details of what’s happening during the night. So these sleep cycles are something that neuroscience with the EEG method finally helped us figure out. And with the EEG method, we could see that there’s repeating patterns of activity in the brain as well as in our eye movements and parts of our body, in the heart, and so forth. But the brain activity seems to progress through a series of different stages that have been classically defined, and we still have more to learn about them. So just because we’ve given them names doesn’t mean we understand all about them. But the first stages of sleep we call light sleep, and we sometimes call them stages one and two, and then the third one we call slow wave sleep. And that’ll happen maybe 20-30 minutes after you fall asleep, depending on how much sleep you’ve had recently. And this is a really important stage for memory processing.
Phil Stieg: And when do dreams occur? Is it during that phase called Rapid Eye Movement – or “REM” sleep?
Ken Paller: Dreams can actually occur in many different stages. If we wake people up during REM, they’re more likely to tell us they were just having a dream. But that can also happen in other stages, maybe not with the same qualities always. And it’s a tricky thing to ask people what was just happening in your mind when you have this transition from sleep to wake. So often we don’t remember our dreams, but that doesn’t mean we weren’t dreaming.
Phil Stieg: I’m a guy that loves to fall asleep with the TV on. Is that disrupting these kind of cycles? And is that bad for me?
Ken Paller: Yeah, it’s bad. Don’t do that, Phil. Don’t do it, actually. (laugh)
Phil Stieg: You just has ruined my life! (laugh)
Ken Paller: Yeah. When you’re falling asleep, it’s fine. If it lulls you to sleep, no problem. That’s good. What I think might possibly be detrimental is the idea that your ears and your auditory system are still tuning into it throughout the night. So if you keep it on, that information is coming into you. And what is that information? Is this some advertising that you’d like to get in, or is it something you want to be pushing around your brain activity? Because that’s what we do in my lab. We have sounds that we present to people during sleep. And the old-fashioned orthodoxy was that those sounds would be blocked by the thalamus and they would not get in unless they were really loud, like your alarm clock, to wake you up. And this was all debunked in the 1950s when it was learned that well those sounds really don’t get in unless you actually wake up momentarily and then the sound gets in. And so that pervasive orthodoxy meant that decades went by without very much study of this phenomenon of how our brain responds with sensory stimulation during sleep. And then we took it on again and published in 2009 to show that, in fact, sounds could influence what memories you process and therefore influence your ability to remember things when you wake up. In other words, the sounds are getting in even though you don’t know what’s happening. And that’s the experiment you’re doing in your own home if you keep the TV on all night.
Phil Stieg: I guess I’ll just read myself to sleep tonight… So let’s get into your research. As I understand it, you are trying to communicate with people while they are having lucid dreams. First of all, what is a lucid dream, and how common are they?
Ken Paller: Some surveys have shown that maybe half of people have had a lucid dream. It’s defined as a dream that you understand as a dream during the dream. Now, most dreams, when you wake up, you realize it was all a dream, and that thought had never occurred to you while you were in the dream. Even if bizarre things happen, you go with it. And only when you wake up do you realize, oh, I was sleeping, and that was a dream. But a lucid dream is different because you realize in the context of a dream that it is just a dream, that actually you’re sleeping somewhere and your brain is producing this fantastic story that you’re living. And you can in fact, continue to stay in it and experience it with the knowledge that it’s a dream.
Phil Stieg: And the communication that you talk about that can occur during lucid dreams. I presume it’s something different than me having the TV blaring in the background.
Ken Paller: Well, to really answer your question, I want to go back a little bit to talk about slow wave sleep first.
Phil Stieg: Okay.
Ken Paller: So in slow wave sleep, we’ve been trying to study how memory consolidation progresses, though. How do you reactivate memories during sleep to benefit your ability to use those memories when you’re awake? And one of the methods we used to study that phenomenon was called “targeted memory reactivation.” And in this method, we present sounds to people that make them reactivate memories they’d formed recently before they went to sleep. And it allows us to show how memories are processed during sleep and how that improves our ability to recall and retrieve information when we wake up.
So after those studies had been done, we realized that if we’re very careful, we can present soft sounds to people that don’t arouse them from sleep. They don’t wake them up, but nevertheless are picked up by the brain and influence memory storage in the brain. So we then had some additional questions we wanted to ask, which is, can we get information into people and actually have them be aware of it in the context of a dream? So we use lucid dreaming because people could get the information we were presenting to them and understand that it was coming to them from an experimenter on the outside talking to them in their dream. So the same method we’d use presenting very soft sounds that don’t wake people up but that get in. And in this case, we asked, well, if a person is sleeping, can they hear us? Can they hear us correctly? Do they actually hear what we’re saying rather than some distorted version of it that might be corrupted? And if so, can they answer back and let us know in real time what they’ve heard? And in fact, it works, and we can do just that.
Phil Stieg: How can you tell it’s working? How do people communicate with you while they’re asleep?
Ken Paller: People come to our laboratory, they get hooked up with EEG electrodes on their head, then they have to fall asleep. If that works, they have to have sleep that goes on long enough to get them to a REM period. If that works, then we present some information to them to remind them that maybe you’re dreaming at the moment, think about your presence experience and decide, am I actually awake? Now or am I asleep? And we have to do that so they don’t get woken up. And sometimes we make mistakes and it wakes them up. But if we’re successful, they stay asleep. We monitor their brain activity and know they’re still in REM sleep, and then we can ask more questions of them.
We started with math questions. We used math questions because we wanted to assess whether they were hearing it correctly. And given that we knew what the answer to the math problem was, we could tell if they heard it correctly and also could issue the answer.
How did they issue the answer? Well, they couldn’t talk to us because there’s muscle antonia, during REM sleep, the muscles are paralyzed, in a sense, and you can’t just speak under normal circumstances. But the eyes are an exception, and you could move your eyes around in your dream body, and your eyes in your actual body move around, too. So these are methods that we can use to have people communicate back with codes. For example, one code was move your eyes to the left, right, left, right. And if you do that, left, right, left, right, you’re telling us, “I understand that I’m asleep right now having a dream.”
Phil Stieg: What I have a hard time getting my arms around is that you’re saying the person is still asleep, you’re communicating with them, they’re responding, which to me implies that they have something going on in their higher cortex and the cortex has slow wave sleep going on. I don’t know how this all gets integrated. Can you simplify that for me?
Ken Paller: Part of it is a dream is like waking in a sense, except there isn’t sensory input coming in, but your brain is still creating an environment and experience of being somewhere. And our brain can do that, even if there isn’t any sensory input, which is kind of an amazing phenomenon in itself. So when our sounds come in, they actually do leak into the dream, though not always. Sometimes they don’t. But when they do, the person in the dream might say, oh, I heard this voice just coming from the ceiling or it was coming from outside. Or in one case, they said I was in a car and it was coming from the car radio. So it gets integrated into their dream in some way or another to be part of the experience even though you’re asleep.
Phil Stieg: And when the patient wakes up, do they remember having this interaction?
Ken Paller: Sometimes yes, but sometimes no. But the interesting thing is that when they remembered, we could then say, well, we have the physiological data saying we asked the math problem, and they answered it correctly. And then they woke up and they told us what the math problem was, and then they answered. So we have convergence on that, which is a much better way to study dreams than just depending on what people say when they wake up, which is why the science of dreams has been so challenging.
Phil Stieg: Reading through your material, I couldn’t help but think of The Manchurian Candidate. Do you envision some time where we’re going to be able to manipulate a person’s sleep cycle and their dream state and then subsequently control their actions?
Ken Paller: Well, I think we need to keep thinking about the ethics of this work and be careful about what might be used, what could be done. I’m not exceedingly worried in one sense, because I think it’s a little bit like trying to convince people of something that they didn’t agree with. And I’m not so sure we can implant ideas that don’t fit with something they already think when we’re talking to people in their sleep. So we may be able to make suggestions to them, but I don’t know that we can convince them of something else. The ethics needs to be thought through and considered because we’re still just beginning to establish what’s feasible and what isn’t.
Phil Stieg: Every now and again you see something in the news that you learn something fantastic like a language during sleep that’s probably not occurring by and large.
Ken Paller: Well, I was telling you that in the 1950s, that idea was completely debunked. So we’re suffering because there haven’t been enough studies of that in the intervening decades. And we’re getting back to it now and asking, well, actually, what can happen during sleep? Because it’s not zero, as our studies have shown. But it’s not like an Aldous Huxley story about how a person could learn a whole speech and a language they never heard before by hearing it during sleep. So that doesn’t happen. But yet let’s not close the door on what is possible.
Interstitial Theme Music
Narrator: The idea of learning while you sleep had been all the rage in pop psychology prior to being debunked in the 1950’s. A century ago there was no greater proponent of “sleep learning” than A. B. Saliger, the inventor of the “Psycho-Phone”.
Excerpt from Psycho-Phone record:
I have a strong consciousness in my power to achieve whatever I desire. The things of this world are for me. My service is in demand and…Narrator: Saliger’s patented device was essentially an Edison-style phonograph with a timer set to play the record over and over after its owner had fallen asleep.
Psycho-Phone record:
I desire to prosper. I have complete confidence in the effectiveness of the Psycho-phone for this purpose. The sound of the Psycho-Phone lulls me to sleep, but my unconscious mind is deeply impressed by these affirmations.Narrator: Saliger believed that the messages delivered during sleep would enter a person’s unconscious and have a powerful influence on the individual’s behavior. His claims about the effectiveness of his device were nothing short of miraculous.
Psycho-Phone advertising copy:
“It lays hold if your unconscious mind during sleep, when all interference of the intellect and environment are in abeyance and gets results overnight that would take months or years to accomplish with conscious effort… It enables you to be prosperous, to get money and the things necessary to your highest development!”Narrator: In 1929 the Psycho-Phone sold for $235 – the equivalent of well over $3,000 today. Among Saliger’s recorded titles were “Prosperity,” “Life Extension,” and “Mating.” He claimed to have Hollywood movie stars and successful Wall Street businessmen as his clients.
One wonders — if more of those successful businessmen had been listening in October of 1929, would the history of the Stock Market have been any different?Psycho-Phone record
Money wants me and comes to me. Business wants me and comes to me. I am rich. I am … Success!
Phil Stieg: So what has surprised you most about your results in studying dreams? Was there an “AHA, wow, this is phenomenal?”
Ken Paller: When I had this idea of let’s see if we can communicate with people in the context of a dream, I didn’t know if it would work. And I thought perhaps they’ll hear our voice, but we’ll say, what’s, eight minus six? And they’ll hear “tomato” or something totally different because dreams are so crazy. Something could change. And in fact, maybe it’s surprising that by and large, they heard correctly the words not always, but they heard correctly the words quite often that we spoke to them during their dreams.
Phil Stieg: Your response led to my next question that I was thinking is what is the most interesting or maybe the most humorous response that you’ve gotten in manipulating or altering the dream state?
Ken Paller: I suppose it’s interesting that we asked math questions, and one of the participants heard them in the context of a math class. So she was there in this math class, and so therefore, we must have influenced the course of her dream. And so that connects to dream control. That lucid dreamers now and then have some ability to control their dream. Not perfectly, but they can sort of wish themselves to be able to fly or to be able to go to Hawaii or to be able to open a door and find that Einstein is sitting there waiting to answer their questions. And so one can control their dreams with some modicum of control and ability to make things happen. And we can also, from the outside, suggest ideas about what should happen in the dream. So that allows us to think about, well, if we want to help people, what would they like to do in their dreams that might be helpful? For example, if you want to get a bit better at your musicianship you could practice in your sleep if we remind you.
We have one study of that. We had people learn to play melodies on a keyboard, and the melodies were played in what you might call a game of guitar hero. So you’re watching little circles on a screen and pressing buttons accordingly to produce a melody. And when we played one of the melodies, People had learned they learned two melodies. And if we played one during sleep, when they woke up, they were more accurate at playing that melody Compared to the melody that hadn’t been played during sleep. So, yes, there’s evidence that our music learning abilities depend on sleep as well. And musicians commonly notice that that day after day they continue to practice and they get better and sleep as part of that.
Phil Stieg: I’m interested in your lucid dream app that you’ve created. What does it do? What should I expect if I put it on my cell phone?
Ken Paller: Well, it’s an ongoing project. We’re working to try to bring things out of the laboratory. Sleep wearables help us a little bit because it is possible to do some monitoring in the home without that much difficulty. And one of the things I mentioned in our research is to make our work in lucid dreaming and two-way communication work we needed to provoke lucid dreams. And so that’s one of the things that this app is geared towards is trying to use a similar method to what we used in the laboratory and make it work for people in the home.. My hope is that eventually we’ll have a device that people can use in the home to perhaps have a lucid dream or to perhaps be reminded of something during their sleep that they want to learn or maybe be reminded of a problem they want to solve in their sleep. And that’s still something that we can do in the lab way better than we can do at home, but we’re working on it.
Phil Stieg: So is the goal for the app re-enforcing learning you did earlier in the day?
Ken Paller: Yeah, there’s a whole long list of various uses, and it could be reinforcing some learning. It could be helping with some important learning like rehab. And we have a project right now with the Department of Neurology at Northwestern that’s focused on stroke patients who are trying to do rehab to recover motor skills in their arms. And they do the training while they’re awake, and they were trying to reinforce that during sleep. So any type of learning that could be gradually happening and reinforced during sleep, we are wondering if we can make that work better and maybe just having good sleep is going to be part of it. And it kind of starts with people putting more value into sleep. So not treating sleep as something that’s a waste of time that they just want to get past and then drink coffee to make up for it, but in fact, realizing the value of sleep and engage in what we call sleep hygiene. So all the ways you can do sleep well.
Phil Stieg: That leads me, however, into my next question. I’m really concerned about the impact of social media on our brain and the fact that it really limits the amount of downtime that we have as individuals. Is this just another invasion into my brain’s downtime? And if that’s true, what’s the potential downside to lucid dreaming?
Ken Paller: Yes, well, you’re quite right. We need to think that through and find out how it could impact on other benefits of sleep. A lot of the work in our lab is a basic type of research to understand how this works and what’s the neuroscience of memory and sleep and how does that relate to what people are doing? And then we’re secondarily also thinking about the applications and how to branch out and help people. And we need to carefully consider costs and benefits in all the time.
Phil Stieg: My final question; given all the work that you’ve done, what do you see on the horizon for your next area of research?
Ken Paller: Well, of course, there’s a lot more to learn about what happens in the brain during sleep, how it’s important for memory, for psychological wellbeing, and for problem solving. And so we’re working on those problems. At the same time, we’re also interested in applications and how we can help people use this knowledge and some of our technology. Some of my colleagues came out with a new study on treating nightmare disorders so that’s in the territory, if you can treat nightmares with lucid dreaming methods, you can get a little bit more on connected to perhaps PTSD as well.
Phil Stieg: Dr. Ken Paller, thank you for spending this time with us, discussing not only the importance of sleep and the cycles of sleep, but also how we might manage our dreams more effectively and hopefully be able to apply this management in clinical applications for things that bother us while we’re awake. Thanks so much for spending time with us today.
Ken Paller: It’s been a pleasure to talk with you today.