Speaking of Psychology: Dreams, nightmares, and sleepwalking: What can happen while we sleep, with Antonio Zadra, PhD

Our dreams can be exhilarating, surprising, terrifying, even mundane. But where do they come from and what, if anything, do they mean? Dream researcher Antonio Zadra, PhD, talks about why some people remember their dreams vividly while others don’t remember them at all, whether exploring dreams can offer insight into our waking lives, why nightmares happen and effective treatments for problematic recurring nightmares, understanding lucid dreaming and sleepwalking, and more.

Antonio Zadra, PhD, is currently full professor in the department of psychology at the Université de Montréal and is a researcher at the Center for Advanced Research in Sleep Medicine. Together with his students and collaborators, he has published over 100 research articles and book chapters on dreams and parasomnias. He’s the author of the book When Brains Dream: Exploring the Science and Mystery of Dreams.

Kim Mills: Confronting a monster, realizing you can fly, running into your ninth grade teacher—while you’re not wearing pants. The characters and situations we encounter in our dreams can be exhilarating, surprising, terrifying, even mundane. But where do dreams and nightmares come from? And what, if anything, do they mean?

Those questions have interested philosophers and mystics for centuries. In recent decades, scientists have begun to explore them as well. Today we’re going to talk to one of those scientists about questions such as: Why do we dream? Why do some people remember their dreams in detail—like me—while others don’t remember them at all? Can exploring our dreams offer us insight into our waking lives? What are lucid dreams and can you train yourself to have one? What about sleep paralysis? And what about nightmares? Why do they occur? How common are they? And is there any way to treat them if they’re interfering with your sleep and your mental health?

Welcome to Speaking of Psychology, the flagship podcast of the American Psychological Association that examines the links between psychological science and everyday life. I’m Kim Mills.

My guest today is Dr. Antonio Zadra, a professor of psychology at the University of Montreal, and a researcher at the Center for Advanced Research in Sleep Medicine. He’s interested in all kinds of questions about nightmares and dreams, including how dreams relate to waking life and whether dreams have a function. He’s also studied lucid dreams, recurrent dreams, and parasomnias such as sleepwalking. Dr. Zadra holds an MA in experimental psychology and a PhD in clinical psychology from McGill University. He’s published more than 100 research articles and book chapters on dreams and parasomnias, and is the co-author of the book When Brains Dream: Understanding the Science and Mystery of Our Dreaming Minds. 

Dr. Zadra, thank you for joining me today.

Antonio Zadra, PhD: Thank you for having me. Pleasure to be here.

Mills: I want to start our conversation by putting this right up front. I have always had extremely vivid and convoluted dreams, which I often post about on social media to the vast amusement of my friends, and I often feel as if I’m more creative asleep than awake. So it’s hard for me to fathom people who say they never dream or never remember their dreams. Is that possible? Are there people who are really not dreaming or do they just not remember them?

Zadra: Well, for the vast majority of people, the answer is that they never remember their dreams. And the reason we know that is that we can take people who claim they never dream, bring them into a sleep lab, wake them up at particular sleep stages throughout the night, particularly out of what is known as rapid eye movement sleep or REM sleep, during which our most vivid and narratively driven emotional dreams take place. And if we waken up then, and especially in that particular type of REM sleep known as phasic REM sleep where there’s more eye movements, a bit more body twitching—in over 80% of the time, these people go, Oh my gosh, I was dreaming, I remember this and this. So we think that really everyone dreams, but there is great variability in how often we remember our dreams.

And we also need to keep in mind that even the dreams we do remember, by and large, unless we tell them to someone or write them down, those memories fade pretty quickly. So you might have a pretty interesting, bizarre dream you remembered one morning, but by lunch hour, maybe it’s just the core of it that remains, and by a day or two later it might have almost entirely washed away, except for some maybe core details.

Mills: Where do those memories go as compared to other memories? I mean, do we have any idea why dream memories dissipate so quickly?

Zadra: Well, that’s debated, but one idea is that dreams in and of themselves are not generated to be remembered. And so that is why we have difficulty remembering our dreams. And many people who do remember their dreams even every morning, if you think that you have anywhere—maybe an hour and a half to 2 hours just of REM sleep, where our most vivid dreaming takes place, every single night you go to bed and we know you also have dreams in other phases of sleep. So you’re spending several hours a night immersed in various kinds of dream worlds, of which you might remember just a few minutes every morning. And those memories, like I mentioned earlier, tend to fade.

So we think that one reason is if you were to encode your dream experiences as vividly as your waking ones, your mind would be a mess because it’d be hard to disentangle what was real, what is not real. And there’s actually some conditions, including some sleep disorders such as narcolepsy, where people do encode their dream memories as vividly, at times even more vividly, than their waking life experiences. And they lo and behold, have trouble deciphering, did that really happen? Did my neighbor’s daughter really die in an accident or did I dream that? And if you have hours of that nightly, it becomes really problematic. If we believe maybe that some animals, other mammals that also have REM sleep dream, they have no one to teach them what a dream is. What is imagination, perception, reality? And so if you’re a lion, you just dreamt that you hunted down a zebra and you’re eating it and you wake up and A, there’s no zebra, B, you’re hungry. How do you make sense of that world? And so it’s probably easier never to remember them, and that later on if we talk about the function of dreams, that’s also why we think that the function of dreams, if they have one, happens online as they are unfolding regardless if you remember them or not.

Mills: So that is a $64,000 question, the function of dreams. How much do we know about why we dream?

Zadra: A lot and very, very little. I say a lot because there are literally dozens of ideas and theories about where dreams come from and why we have them and dreams and premonitions, dreams and health, dreams and emotion regulation, and why did they evolve? But in terms of hard science, empirical evidence, these models are hard to test. But we are like in many other sciences, including neurosciences, including our understanding of why we sleep, making considerable progress. And we’ve got to remember that not that long ago we still didn’t really have good ideas of why we sleep.

Mills: How do people’s dreams relate to what is happening in their waking lives? And can exploring that question be a useful tool for therapists?

Zadra: I think it can be a very useful tool for therapists. We do know that when we look at people’s dreams, especially a series of dreams, when you have 10, 15, 20, 30 dreams of an individual over a certain period of time, you can often start seeing patterns in them. What are the main emotions? Where do they take place? What kind of social interactions do they have? Are they friendly, aggressive? They might notice that when Peter’s in your dream or your ex is in your dream, you’re always frustrated or you’re angry or you’re joyful. So sometimes there is emotions associated with certain characters. So that’s just to say that there are patterns we can observe in people’s dreams that fluctuate as a function of our circumstances, but dreams can also be viewed as embodiments of our ongoing concerns, preoccupations.

And so we see that on many levels. We see that in the dreams of people, grief, dreams after they’ve lost a loved one. We see that in people who are trying to stop vicious cycles of drug or other alcohol consumption or other substances, when people are having relapses, in people with suicidal ideation, in people who suffer from depression and people who have even exciting events on the horizon. It could be a wedding, it could be a new job, it could be moving to a new city, but these stressors or apprehensions or concerns we have about it—am I making the right decision? Is this good for me?—often get played sometimes or oftentimes metaphorically in our dream. So an individual dream might look all bizarre and meaningless, but you start paying attention to more of them, and when they are happening, then I think they shine a light into what’s on our minds, what is bothering us, and the kinds of emotions that we are presently dealing with. And probably this is best exemplified of course in an extreme format, but in trauma survivors and how various kinds of traumas are reflected in people’s dreams and including bad dreams and nightmares.

Mills: Yeah. I wanted to get to nightmares, and since you raised them, why don’t we jump there right now? I know that you do study nightmares, and I’m just wondering how common are they? And do we know what percentage of most dreams are nightmares?

Zadra: Those are excellent questions. So first of all, there’s maybe about 5% to 8% of the general adult population who complain of nightmares, who say they have a problem with nightmares. So they are quite common. And to have the occasional nightmare, to have a few per year or so, that is absolutely the norm. Actually I would say—people say, I’ve never had nightmares, and they’re probably never remembering their dreams. And that might happen, but they’re in a minority. About 85% or so of people say they have them at least on occasion. So they are quite common.

And what proportion of our dreams are nightmares? That is a trickier one to answer, but we’ve done a study where we collected close to 10,000 home dream reports. So these are not laboratory dreams. These are the dreams people tend to remember when they wake up in the morning. And so these are the dreams that we tend to have, which are again, the more bizarre, emotionally laden, narratively driven. And roughly 3% of these 10,000 dreams we looked at from several hundred people were nightmares. And about another 10% we could call bad dreams. They were highly negative dreams with all kinds of negative emotions, fear, but also disgust, jealousy, confusion, sadness, but usually not as intense as those that we find in nightmares. So a sizable proportion of our, at least our home dreams contained these highly negative, intense emotions.

Mills: So most of the studying that you do would be in a lab, right? But for nightmares, I mean, you can’t really put somebody in a lab, tell them go to sleep and have a nightmare. Is the only way to study nightmare through self-report?

Zadra: No, you can study nightmares in a lab as well. The challenge, again, it really depends what question do you want to answer? So if I want to know what’s going on in terms of your electrical brain activity when you’re having a nightmare, what goes on in terms of your respiration rate or heart rate? Does it shoot up when you’re having a nightmare? Then that I have to pretty much do in a lab. Ideally, I also, if I want to know, is it happening early in the night in REM sleep? Later in the night? So depending on the questions you have, the lab might a good place to do it.

The challenge with studying nightmares in the lab is that even frequent nightmare sufferers rarely have nightmares in the lab. And so they actually often want to come back to the lab because they go, I didn’t sleep that well—in spite of all the electrodes and so on—in a long time. And so that’s an interesting observation in and of itself. And we think that one explanation for this is they know they’re being monitored over the night. They know someone is watching over them, and that might be something that has a positive impact on them, and they feel maybe less vulnerable with respect to their nightmares.

Now, if I want to know what are the common, most common themes we find in people’s nightmares, how often they occur over periods of weeks or months in some individuals, then it’s not practical to ask someone to come in to your sleep lab and sleep there for 3 weeks consecutively. So then these home dream studies are better. And if we want to know the relationship between, do you have your nightmares or bad dreams because of stress, then I can have you keep a home dream diary and every day complete some questionnaires about maybe your stress levels, emotionally salient events you’ve had. And so then it allows us to plot over time the occurrence of nightmares and what’s going on in terms of your waking life, waking stressors, psychological adjustments and so on. So both methods are useful, they’re complimentary. It really depends—what are you trying to answer in terms of a clinical or research question?

Mills: What are the treatments that are available for people who have frequent nightmares? Maybe they’re suffering from PTSD or there’s something else that’s going on in their lives and it’s become really—it interferes with their daily waking life. How do you treat people who are in that situation?

Zadra: I am really happy that you’re asking this question because we do have very effective treatments for most kinds of nightmares. And it’s true for war veterans, trauma related survivors, children who have nightmares, they’re easy, relatively easy to implement, they’re highly effective. And unfortunately, many people who suffer from nightmares, and including mental health professionals who treat all kinds of psychological issues, are unaware of their existence. And so people and many professionals think there’s not much you can do about nightmares.

Second is many people think, Oh yeah, well, if I’m going to work on my nightmares, then the mental health professional is going to want me to go explore my childhood, my relationship with my parents, what’s going on, and I don’t have the energy for that. And so here, erroneously nightmares are viewed as a symptom of something else. But you can also view nightmares as a primary sleep disorder, a disorder which we can treat directly as a problem in and of itself without having necessarily to go explore any presumed or underlying causes—and that you can have a positive impact.

People end up sleeping better, and many say they are sleeping so much better since they no longer have nightmares or have them a lot less frequently, that they feel more energized, more self-confident. And then if they are interested in doing other forms of psychotherapy or addressing much more ingrained older underlying issues for other reasons, they feel they have the energy to do so. And the same thing happens with trauma-related nightmares.

So what are these treatments? There are mainly two. The number one recommended treatment—when I say recommended, it’s by people who work in the field, the American Academy of Sleep Disorders, again, because it’s where we have the best evidence of randomized control trials, good outcome follow up. One of these treatments, the most common one, is called imagery rehearsal therapy, which in a nutshell is when you have a nightmare, take the time to reimagine it while changing something in it, change whatever feels right to you. Now, often people will say, Oh, you’re supposed to change the ending to something triumphant, whatever. Now you can do that, but you should not tell the people what to change. And some of them will change the ending, some will change the beginning, some will change some minor details. Some will make a friend or supernatural character appear and save them at the end. But there’s part of the exercise of making this decision and working through how you want to change it and how it’ll unfold. That’s probably empowering. And for many people, it’s the first time that they look at their nightmares, not as something that they are helpless to do anything about, but the idea that they can manipulate them, change something really new to them.

So in essence, the exercises, it can be adapted to children through drawings. You can have them draw a different version of their nightmare. And anytime you have these nightmares, that’s what you’re supposed to do. Take a few minutes of your day, engage in these imagery exercises, and then imagine the nightmare in a different format. Now, the sessions can certainly be more complicated than that. Some people have trouble using active imagination. Some people have at first have trouble trying to imagine these nightmares, especially if they remind them of very painful events. And so sometimes there’s exercises you need to do, relaxation exercises, imagery exercises. So start by learning how to imagine a positive scene. So sometimes there’s these things they need to do, but by and large, imagery rehearsal therapy, as I say, is something relatively simple, no real side effects. We’re talking just about a few sessions. You give these people these tools, which they go and practice at home. It can be done individually, in groups, and by and large, there is clinical improvements observed anywhere between 75-85% of those populations, which is really quite an astounding figure. We have very few treatments in psychology for anything with that level of success.

The other treatment is a pharmacological one and is really only recommended for people who have severe cases of post-traumatic stress disorder. And for instance, if we’re talking about people in combat areas, they might not have access to someone to do imagery rehearsal therapy, what have you, but they might have access to medication. And we know people who suffer from post-traumatic stress disorder in their sleep, a key neurotransmitter, hormonal modulator known as norepinephrine, their levels become abnormally high during their sleep, including REM sleep, which is probably why they have dreams that replay the traumatic events.

Now, you’re mentioning at the outset, Kim, that you have these when you remember your dreams, that tend to be very bizarre and so on. And that’s true of many people. Our dreams rarely replay our events of waking life as they occurred, right? There’s often there’s twists—the setting is wrong, the characters are wrong there, things are blended, or it starts off in this place and then goes to another one. And that’s how dreams are constructed. People who have PTSD tend to replay these negative, strong, traumatic events from their lives, and we think part of that are due to these imbalances in their neurotransmitter systems. Prazosin, this pharmacological agent, which is actually originally developed for hypertension, for high blood pressure, has as a side effect if you want, normalizes, brings back down to normal levels, these levels of norepinephrine in your brain, particularly during REM sleep. And that we think inhibits the formation of these episodic memories in our dreams, memories of events as they happened.

So regardless of what kind of nightmares you have, trauma related, stress related, and there’s some many what we call idiopathic, which is a fancy word meaning we don’t know why you have them. And again, imagery rehearsal therapy works very well, first line recommendation, and again, in cases where access to these kinds of treatments aren’t available, Prazosin for more trauma related ones is a plan B. So there are things people can do. And then there’s other things. There’s relaxation exercises. There’s something called lucid dreaming, becoming aware that you are dreaming, but these tend to be harder to teach, not as effective. And so when I see people working on these new treatments for nightmares, sometimes, honestly, I think – why? We already have something that’s really simple and we know works really, really well.

Mills: You mentioned lucid dreaming a minute ago, and also as you were describing imagery, rehearsal therapy, it sounded to me a lot like the self-training that you might try to do if you wish to have lucid dreams. Can you talk about what that means to have a lucid dream, why people are interested in doing it?

Zadra: Well, lucid dreams essentially are dreams in which you are aware that you are dreaming while you’re still in the dream. And people are interested in either learning to have lucid dreams, or having them more often, because they’re associated with an idea of being able to influence or control the outcome of your dream. And so people think, It’d be great if I could soar through the air tonight in my dream or meet person X or Y, or I do these activities and so on. Now that can happen, but people often underestimate how tricky and hard it is to have these kinds of lucid dreams. So before I was mentioning nightmares, some people at the very end of their nightmare might go, Oh my gosh, yeah, this is just a dream. And they wake themselves up. So were they lucid? Sure, for one and a half seconds. That’s it.

On the other hand, you have people who can become aware. They’re dreaming, they know where they are asleep. They say, Yeah, I’m at visiting my girlfriend, or I’m in my apartment, I’m sleeping here. I got an exam tomorrow. So they have access to some kind of memories of their daytime lives and then to various degrees, they can use this awareness to try to manipulate or change how the dream unfolds. So you might be having a dream where you are at work, you’re stuck in traffic, you’re in a class, something that is sort of mundane, you want something more exciting, then you can try to transport yourself through lucid dreaming to an outdoor café in Paris, to the moon, to whatever. Now that might work. That might not work. And so becoming lucid, I tell people, that’s the easy step. Becoming aware that you’re dreaming, that’s the easy step. The hard step is how do you go about using this awareness to change the dream if you want to do it, and to do it in a way that you don’t get overly excited so that you wake up.

We’re talking about nightmares. And often people wake up because the emotions they feel in them become overwhelming. They overwhelm their system. They’re so scared by what’s about to happen, they wake up. But being over enthused, overjoyed in your dream can have the same impact. On the other hand, it’s very easy also to forget that you are dreaming and to fall back into non-lucid dreaming. And so you’re sort of on a tight rope on one side, you get overly excited, you wake up on the other one, you’re a bit too detached and you lose your dream lucidity. So all I’m saying is that it’s great fun. Lucid dreaming is actually the reason I got interested in dreams—is from a really wild, lucid dream I had while I was in college, the first dream I ever wrote down. And that’s what sparked my interest in all of this. So it literally was a life-changing dream because it changed my career path or what I was aiming for. But it’s not as simple as many people or as easy as many people make it out to be.

Mills: I want to change gears for a minute now and talk about sleepwalking or parasomnias, which is a great word. I have a really good friend who at one point in her life, she would go to bed, go to sleep, and at some point she’d get up, she’d unlock her apartment door, she’d vacuum her living room in her sleep, and then go back to bed—no consciousness. She’d get up in the morning and the vacuum cleaner’s in the living room, the door is open. And she realized that she was doing this. What makes people sleepwalk? Why do some people sleepwalk and do wild things, and some people never sleepwalk at all?

Zadra: That’s an excellent question. So we know that most people who sleepwalk have a genetic predisposition for the disorder, for sleepwalking. So it tends to, no pun intended, run in families. Now, the kinds of behaviors people engage in are really very variable. Some people have fairly mundane episodes of sleepwalking. They might just sit up in bed, point at a wall, mumble, play with their bedsheets, maybe get up and then go to sleep on the couch, whatever. They’ll wake up somewhere else, but they’re not in any risk of injuring themselves, injuring others. You mentioned your friend who would go up and who would get up and vacuum. That’d be good. That’s really effective use of her parasomnia. Maybe tack on doing laundry and so on—folding. That’d be a good use.

So some people do engage in these activities. We’ve had musicians, even, from local orchestras here who were sleepwalkers and during their episodes would play, would take out their musical instruments, start playing it. So you’re hearing a cello at 2 in the morning where your neighbor isn’t all that thrilled. On the other hand, there’s people who put themselves in situations of danger. They can unlock the door, leave the house. I’m in Montreal. February here is pretty cold, snow, ice. They might leave their home just in their underwear or in their pajamas, get severe frostbite, cross the street risk of being hit by an automobile. Some have very agitated episode. They think there might be an intruder in the house. People have unintentionally, of course, spat on their children because they did not recognize their children during their episodes. And some people have manipulated firearms, knives during their episodes, have gone up on roofs. So they’re putting themselves in situations of danger.

And so it’s the ones who have these more agitated complex episodes, who are the ones who are most likely to come to a sleep clinic. So there’s the genetic predisposition, and then why do you have an episode on Tuesday, not on Wednesday? Why do you stay 2 weeks without having any? And then you have three in one week. And we know that having irregular sleep schedules, being sleep deprived is one factor that contributes to why you have it one night and not another. The reason is that sleepwalking occurs in slow wave sleep. Our deepest stage of sleep we have tend to have most in the first third of the night. But if you are sleep deprived, either acutely because you’re doing shift work because you stayed up all night to study what have you, when you go back to bed, that is the stage of sleep that’ll come back with the biggest rebound.

Not all stages of sleep resurface equally. So that one has priority. And because episodes occur out of slow wave sleep, if you have a lot more of it and it’s more intense, you’re more likely to have a sleepwalking episode. Many will say also, if they are in periods of stress, and it doesn’t matter what the stressor is, it could be a financial stress, could be a good stress. If you’re going to give birth to a child, you’re starting a new job. Anything that stresses you can also facilitate the occurrence of sleepwalking. And incidentally, sleepwalking takes place—the people are not fully awake, nor are they fully asleep. When we look at what’s going on in the brain during the episodes, some neural circuits are fast asleep and some of them are partially awake. And depending what circuits are doing what you have agitated episodes, calm episodes, people talking, understanding people are really agitated, and when I need to get out of the house, they think there’s an immediate danger because there’s a noise in the room, a disturbance. They’re changing positions in bed.

Normally, a non-sleepwalker, we might just wake up—there’s a bang in the room, for instance, a sudden noise—for sleepwalkers, their brain gets stuck transitioning from slow wave sleep to wakefulness. It gets sort of stuck halfway. Some parts of the brain are awake, others are still asleep. And that what gives rise to the state. And that’s why you’re mentioning a friend who would vacuum. Well, if you’re vacuuming, you got to be able to see your bedroom door and open it and see where the vacuum is, and then to be able to find the electrical cord and plug it in. So you are interacting with your environment. On the other hand, your logic might be completely off. You look at the sleepwalker do something, and you go, my gosh, what are they doing? And it makes sense once you know what is going through their mind.

So the other example I like to give is someone who during the episode sees his dog, which is on his bed and his real dog was on his bed, jumps out of bed, grabs the dog, runs to the bathroom, turns on the shower, and throws the dog under the shower head. Now again, the spouse is like, what are you doing? But he had seen little flames shooting off the dog’s fur. So if you think your dog is on fire, well that action makes perfect sense. So sleepwalking is also very interesting because it raises all kinds of questions about the mind—consciousness, volition, are we responsible for our acts? Do we remember them? There’s all kinds of also medical, legal implications. So a fascinating, to me, sleep disorder.

Mills: It sounds a lot like migrating birds that can put half of their brain to sleep and they can continue flying. I mean, have you found similarities in that respect?

Zadra: Well, for the migratory birds you mentioned, or dolphins and whales who also have what’s known as unihemispheric sleep, which is half the brain, one hemisphere sleeps at a time. Migratory birds, that allows them to fly days on end as they’re crossing the oceans. For example, some dolphins, they need to surface to breathe. And so the reason they had unihemispheric sleep is that it allows part of their brain to sleep and the other one to go, Oh, okay, it’s time to surface, we need to breathe.

And so it is analogous in the sense that sleep and wakefulness are co-occurring or coexisting inside a same brain at the same time. Just that in the case of migratory birds, some species of ducks and other mammals, it has an evolutionary basis. It works. Here, it seems to be a bit of a breakdown in how these systems, which are very complicated to work, and if we think transitioning from wakefulness to sleep to back from wakefulness is things we take for granted. But it’s like going under anesthesia. I mean, you lose consciousness and there’s a lot that goes on in your brain to allow you to fall asleep and then to bring you back into wakefulness. And a lot can go wrong in there as many people with all kinds of sleep disorders starting with insomnia, unfortunately, know. But yes, what you mentioned are interesting parallels that show us that having sleep and wakefulness coexist in the brain is something that we can naturally observe in other species.

Mills: So last question. I want to ask you about your concerns that I know you’ve expressed around dream hacking, where advertisers try to work their products into our dreams. Can you talk about that? How well does it work? Is this something that we should be worried about?

Zadra: Okay, so it’s not something that is ongoing now. And as far as I know, I haven’t been paid by some secret sleep advertiser to say that. But there is this growing technology that is being used for good, for treating nightmares, for mental health issues, known as dream engineering. And dream engineering is the use of various technologies and techniques to try to influence some, manipulate dream content, and it can work quite well. But like many things, many technologies that work well, they can be used for different reasons. And so we do have enough evidence to believe that it wouldn’t be that farfetched to use some techniques or develop variations of them to engage in product placement while we dream, of which we may not even remember having dreamt of that, and these can be images that are implanted, but it can be auditory stimuli that are presented in our sleep.

And now as more and more people have sleep trackers, have different monitors during their sleep at home, various wearable devices, devices also that record your sleep, I mean, any sounds, which can be really useful because you want to know—are you snoring? Are you not snoring? You can have these apps that will record you. But there’s nothing precluding these apps from sending you stimuli. And if you’re sleeping with a sleep wearable, then the company might know when you’re in REM sleep, when you’re in deep sleep. And so know in which phase of sleep these stimuli might be most effective to influence your choices, behaviors, purchases. And so are we there now? No, we’re not. Could we be there in the near future? Certainly.

And there’s at least 40 sleep and dream researchers who are worried enough that we all signed this letter petitioning to put guardrails. We should have one last refuge where we are not exposed to advertisement, and that is our land of dreams. My so to speak nightmare is one day where I’ll be able to say, Kim, give me $10 a month and I’ll guarantee you ad-free dreams, you can opt out. I think that would be a horrible world to be in. And so we’re bombarded sufficiently and personal data collected sufficiently throughout our waking lives and activities that we think that sleep and dreams, which also have very important functions, should be off limits, especially since there’s good evidence that you can do these manipulations that can impact people’s choices. Even for a brand of candy, for instance, has been shown to work, but they have no idea why they change from Smarties to Skittles, things of that nature, but it’s because of stimulation presented during their sleep. And so I think that anything that can change people’s views, preferences, without them knowing why that is, the key to me is something should be off limits.

So like I said, it’s not here now, but we think we should maybe be proactive and vigilant. And if we think what advertisers are willing to spend for 30 seconds of advertising during the Super Bowl or during some highly rated shows or podcasts or what have you, how much are they willing to spend if they can have a technology that can access your mind for a couple hours every night? Well, it turns out a lot. And if researchers with meager means like many sleep researchers in the world can do these various simple experiments, if companies with a lot of means and a lot of resources could certainly develop techniques that are much more effective and potentially much more harmful, depending on how you view it. We are concerned more about what lies down the road and things should be proactive rather than 10 years down the road going, Oh my gosh, this is horrible and how do we get out of it? Which is what we’re basically doing now with many other technological developments.

Mills: Well, I’m glad to hear that you’re working against that. I think we all have enough to worry about in life right now. So, Dr. Zadra, I want to thank you for joining me today. It’s been really interesting.

Zadra: Oh, it’s been fabulous exchanging with you. Thank you for having me.

Mills: You can find previous episodes of Speaking of Psychology on our website at speakingofpsychology.org or on Apple, Spotify, YouTube, or wherever you get your podcasts. And if you like what you’ve heard, please subscribe and leave a review.

For those of you who want to know more about psychology and the work of APA, you can join us as a supporter. You don’t have to be a psychologist. The benefits include a subscription to our award-winning magazine, Monitor on Psychology, as well as discounts on our books and other publications. So if psychology is your passion or if you just want to know more about the science, you can become a supporter by visiting at.apa.org/speaking. That’s at.apa.org/speaking. If you have comments or ideas for future podcasts, you can email us at speakingofpsychology@apa.org. Speaking of Psychology is produced by Lea Winerman.

Thank you for listening. For the American Psychological Association, I’m Kim Mills.