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Dreams and Anaesthesia: Guest Pilleriin Sikka
234 Plays1 month ago
In their second episode in a series on dreaming, Joe and Rolf are joined by Dr. Pilleriin Sikka, a Stanford neuroscientist who is currently studying the therapeutic value of dreams under anesthesia.
Hack, L. M., Sikka, P., Zhou, K., Kawai, M., Chow, H. S., & Heifets, B. (2024). Reduction in Trauma-Related Symptoms After Anesthetic-Induced Intra-Operative Dreaming. American Journal of Psychiatry, 181(6), 563-564.
https://psychiatryonline.org/doi/full/10.1176/appi.ajp.20230698
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Transcript
Introduction to Cog Nation and Guest
00:00:06
Speaker
All right. Well, welcome to the show. This is Cog Nation, and I'm Joe Hardy. And I am Rolf Nelson. And on the show this time, we have a special guest, Pila Rinsika, who is currently a postdoctoral researcher at the university of and Stanford University School of Medicine in the Department of Anesthesiology. She is also affiliated with the Stanford Psychophysiology Laboratory in the Department of Psychology.
00:00:35
Speaker
And she's on the show today to talk about some of her research. So Pilarin, thanks for being on the show. Hi, and thank you very much for inviting me. Excited to be here. Great to have you.
What is Anesthetic-Induced Intraoperative Dreaming?
00:00:46
Speaker
Yeah. And so we're going to talk a bit about some of your research, in particularly related to dreaming. And and this kind this is kind of a part of a series of shows that we're doing on dreaming. And this is a very interesting take on the dreaming work, which is to look at anesthetic induced intraoperative dreaming. ah And so I'd love to hear a little bit about you know what that is and also a little bit how you got interested and in that work. um Thank you. So maybe I'll start from the latter question then. um So i I became interested um that
00:01:29
Speaker
um I, my original interest was and still is, of course, consciousness, trying to understand consciousness, our conscious experiences, like what it is and why, you know, the big old questions, why there is something rather than nothing. And like, how can we understand if somebody is conscious or has conscious experiences, right? And one,
00:01:56
Speaker
i I thought that one good way to study it would be to study dreaming because dreaming is an interesting phenomenon where you are essentially disconnected from the environment, right? You are kind of lying in bed, not moving, um almost essentially paralyzed, at least during REM sleep. And you're not really processing sensory information that is around you in the environment.
00:02:21
Speaker
ah Well, you do process to some extent, we wake up if there's alarm and stuff, but generally disconnected. And typically consciousness has been studied as a reaction to stimuli in the environment, but dreaming, you know, it's like you are disconnected from this environment, but then you have the whole world produced in your brain. You have like all kinds of experiences.
00:02:40
Speaker
They can be very vivid, very intense. You know, I'm sure many people who are listening have had dream experiences and know what it is like to dream. So it's a very interesting. So in in essence, we have this kind of pure phenomenological consciousness that we can study the pure phenomenology without but yeah're kind of like disconnected from the stimulation.
00:02:59
Speaker
a motor output and I was interested in like wow maybe perhaps a bit naively when I started that a long time ago for my PhD was like oh but if we we could figure out the neural correlates of these dream experiences that would be one way to understand what are the neural correlates of experiences right when people are having experiences when they're not in a particular environment and then we can you know get closer to understand when somebody is versus is not conscious right and what the conscious experiences are what they're having and it's not only like in terms of dreaming that it's of course it's cool and exciting like one day to have maybe a dream catcher that we can capture you know people's experiences and see them kind of online like a sci-fi thing online what they're But that's kind of just cool and interesting and fun. But then also, you know, in cases where people are unable to respond, like, for example, when we think of people who have been diagnosed vegetative, like being in this vegetative state or unresponsive vagueness symptom ah syndrome, where we know that some people are misdiagnosed and they might have experiences, we just, the only way we can understand this is with, you know, they can respond to us. But if they can't respond,
00:04:01
Speaker
So how can we understand like, and if we could measure like brain activity, if we knew what would be the correlate, we could see whether they are having any experience,
Research and Therapeutic Potential of Dreaming
00:04:08
Speaker
maybe dreams even. And if, you know, just even that, and then of course what they would be. Of course, I was naive and, you know, we're not much closer to where we are. We can't really capture conscious experience. We don't know what the neural correlates are like.
00:04:20
Speaker
ah but But that's how I got interested. And of course, then I started studying dreaming and I found a whole new world of like, okay, it's so difficult to study dreaming. How can we study it? I've tried to figure out how can we study better um dreaming itself. And then I got interested in how dreaming is related to our waking well-being. Like, does the dreaming dream experience, are they impacted by our waking?
00:04:43
Speaker
experiences and then these in turn how the impacts are waking well-being. So that was another question and from there now I ended up here where currently ah at Stanford we are studying um dreaming during anesthesia and first try trying to understand as a phenomenon like what happens what are the neural correlates but also trying to purposefully induce those dreams ah with the intention to find out whether this can be used to like therapeutically to treat, for example, certain of mental health conditions. So that's kind of like the way from how I got interested in dreams and how I ended up now studying anesthesia dreaming. And yeah, sorry, go ahead.
00:05:22
Speaker
I want I wanted to pause and think a little bit just so people are on the same background here. um If you could describe a little bit about the neural correlates of normal dreaming experiences, sort of what's going on in general in the brain during during dreams and ah sleep in general, but in particularly during dream states.
00:05:44
Speaker
Yeah, that's a great question. And on the one hand, it has long been thought, you know, when with the discovery of rapid and when sleep brim in the you know middle of the 20th century, we thought that, hey, we have figured out the neural correlates of dreams because dreams most typically occur during REM sleep. So I thought, oh, now we have figured out also the neural cause of dreaming. But of course, things are not as easy as we thought they are because dreams also occur during non-REM sleep and actually quite frequently, like let's say up to 40-50% of the time, so it's not infrequent. So and you the cords of REM sleep do not explain ah dreaming. So there has been now work, of course, trying to understand what are the neural cords of dreaming.
00:06:23
Speaker
um Not too much. I would hope that we we would know more, but like there have been some very, very cool studies by, for example, Francesca Siclari, who has tried to understand specifically, ah comparing extreme experiences but to no experiences during different types of during REM sleep and non-REM sleep.
00:06:43
Speaker
And what she has found out using then EEG, which is electroencephalography, which enables to measure electrical brain activity, has found that, well, it's the having dream experiences seems to be associated with reduced low frequency activity and increased high frequency activity in the posterior parts of the brain. So towards the back part of the brain where you have like where you typically process sensory input, especially from visual areas, but also from other sensory areas like auditory and some other motor. So there's the kind of what they call the posterior hotspot, a kind of um
00:07:19
Speaker
area in the brain where it seems the sensory information gets together and you see that increased activity there seems to be at least associated with dream experiences so that is kind of maybe and then then of course the particular contents of dream experience so if you she has also just found out that if um or showed that if you for example have people like with faces in the dreams then you see activity in in areas that typically process facial information like facial form area if you have if you think like you know often we also think in our dream we think what should you do and what other people are doing and and then you have more like activity in the prefrontal areas so so there seems to be like a nice ah correlation also with content-wise with these areas that we typically know are involved in similar processing, processing similar information in wakefulness so
00:08:07
Speaker
But but like whether it's a correlation and and what's the causation, that's of course a different question. this this This is so far what we seem to know that this is very likely kind of correlate or like, let's say, this is what we know right now. And we are trying also to test this, um looking at what happens. um What are the neural correlates of dreaming in anesthesia? And it seems to be very different because um you know it's also funny, typically how we define dreaming is having subjective experiences during sleep. And now what we find out is that, ah well, we have we can have dreams during anesthesia. And anesthesia as a state is actually different from non-REM and REM sleep, which is like, okay, so,
00:08:49
Speaker
and we don't know what, we're trying to figure out what are the correlates of of dreaming during anesthesia because that will also help us get closer to what are the new requests of dreaming irrespective of sleep or respective whatever underlying state there is.
How Does Anesthesia Affect Dreaming?
00:09:02
Speaker
Okay, so when we say dreaming under anesthesia too, I guess most people would think I hope I'm not doing a whole lot of experiencing under anesthesia. Are we talking about ah just lighter levels of anesthesia? So just sort of varying the dose so that you're not totally knocked out? Or how does that work? Yeah, great question. So yeah, and so this has been one thing why for a long time it was people were trying to get rid of like didn't want even talk about dreaming during anesthesia because the worry was that oh my god what maybe what if means that people are actually aware of the surgical environment and what is happening to them so everybody tried to get rid of it like as long as there's no experiences um so but what we see is actually people do have dreams um well
00:09:49
Speaker
when they emerge from even very deep anesthesia, right? like We don't know, again, we have difficulties knowing when the dreams occur. They'll think we know when people were dreaming, we they wake up, we ask, when did you dream, right? And so we know that it happened during anesthesia, even if they had very deep like surgical level sedation, they are unaware of the environment. So we also ask, for example, anesthesia, first thing, what was the last thing you remember? What is the first thing you remember? Did you have any experiences? And so people often have dream experiences,
00:10:19
Speaker
but they are unaware of the environment they are in so which is a great thing they are not aware there is no intraoperative awareness it's it's again very purely this kind of disconnected conscious experience a state of disconnected experiences where you having the full-blown experience but you're not connected in any way to what is happening around you with you which is of course great to know so yes yeah but again we don't know when it happens what because in we don't wake people up usually Well, it's very difficult to wake people up when they're very, very deep, right? Then, you know, usually surgery happens then. It's when when you kind of start lightening the anesthetic doses. And so the question is, does it happen then the dreaming, which is then the kind of emergence from anesthesia, which we assume probably is happening.
00:11:04
Speaker
And content wise, do you get dreams that are more ah REM type dreams during anesthesia or are they more non REM sort of more mentation type dreams ah during anesthesia? Yeah, so we're trying to figure that out. I think we have like both. Well, actually, sometimes, like, for example, we started from that the the the case, the case series that we just published where we had this um women who, when we tried to induce streaming, where I found emergence from intraoperative anesthesia, um they had really, I would say, vivid, emotionally intense um experiences that would be more like gram-like. And also, we are now doing like studies in laboratory, non-surgical settings. So we are actually experimentally inducing dreams during anesthesia.
00:11:56
Speaker
um And we also see some dreams that are very REM-like and others are less like, yeah, like just like images of, you know, on one hand you can have, I don't know, somebody just had this kind of experience where she was an alloy and in a grid of metals and talking to other metals or talking to a parent. What is that really bizarre nature? Very bizarre, which is typical of REM dreams. And at the same time, you can have, oh, I was in the meadow with my dog. So there's variation. But there's been also a previous study published by a Finnish group, which they directly compared the dreams to other sleep dreams and found that they're more similar to non-REM sleep dreams. But what we see is basically
00:12:40
Speaker
Yeah, it varies. And then the question is, okay, why and how, and well, we're trying to figure that out. How do you pick apart the, you know, whether someone is having a dream, but can't remember it versus, you know, just never had a dream? That's a million dollars. Of course, it's very difficult. We don't know. um Because obviously what we know is what people report us, what they report us is what they remember. And, and so of course, it's very much inter Yeah, intertwined with memory, right? Like, we only know what if they remember. And of course it's very likely that, like the same with normal dreaming, right? That people might have dreams. And mostly that's why people say they don't dream because they just don't remember them, right?
00:13:22
Speaker
um And this is it because like, do we actually all the time dream and we just don't remember the other things or yeah. So that's a question. So right now we are not able to do that. That's, if one day we can figure out the neural correlates of experience and the memory consolidation, then we're probably able to know. But right now we just have to rely on that kind of, it's the recalled experience that we're measuring really. Yeah, that makes a lot of sense. In the case of anesthesia and anesthesia dreaming,
00:13:51
Speaker
Are there manipulations to the anesthetic that you can do that make it more or less likely that people will remember their dreams? Yes. So two things I would like, one is like in the surgical setting, it's difficult to manipulate, right? Because there are the ideas just to do normal anesthesia. You will put people under a steep sedation and then, you know, you don't want to do anything else, then just make them sure that they're and under, like, really unconscious. But like, so this is where the the anesthesia dream project started, is Dr. Harrison Chow, who is a clinical anesthesiologist here at Stanford, started like
00:14:22
Speaker
ah to develop this technique where you know usually in the surgical setting people are woken up very fast like so surgery is over and then let's get the person up and out of the operating room and so he started doing this kind of slow emergence where you turn off the anesthetics and you let you give time for patients to emerge right so they kind of slowly come out and that seems to um And also he's like observing online frontal EEG activity, which he can measure using a set line, which is a kind of commercial tool um where he's kind of seeing that there's
00:14:56
Speaker
there's a reduction in alpha power in the frontal areas, which is typically associated with proper fall anesthesia, and it seems to start fading away. And you start seeing increases in high-frequency activity, beta expand in frontal areas. and then he's oh And then he tries to keep the patients in that state without waking up immediately, but tries to keep it at least, let's say, 10, 15 minutes. That seems to be ready to dreaming. And he has been very efficient in in then producing or like producing a state that is conductive to dream experiences. So people very likely, and he seemed that people seem to be like much awake and better when they wake up, they're able to talk, they are not confused, they don't feel bad. So that seems to be, so there you just kind of manipulate basically at the dosage to turn it off, but not fully, and you let them slow emergence. Now we are doing this now in ah in a non-surgical setting, in experimental setting, where we're actually manipulating our different parameters.
00:15:47
Speaker
So it seems that one is the level of anaesthetics, the other is like the speed of which you kind of people emerge. So it's many things, it's there it's the type, the dosage, the speed of emergence um that that we're trying to manipulate and And we're trying to find out this kind of soft spot where people are still anesthetized and fully sedated so they're not aware of the environment, but they are ah aroused enough or at least the cortex or brain is activated enough to have experiences and keeping them in that state. In a surgical setting, it seems to be actually easier because there are also other drugs on board in addition to, you know,
00:16:26
Speaker
let's say propofol in this experimental setting we're just using propofol now so trying to get people in that sweet spot um like just below the surface of like awareness and a and so we're trying to figure out what's the best protocol and we seem to be like quite efficient now in in trying to in getting this state where people would dream and and then they wouldn't dream um so So independent of dreaming, and this is just sort of my ignorance in the topic of anesthetic, what are the general effects that prophenol or similar kinds of anesthetics are having on the brain?
00:17:04
Speaker
Yeah, so on the one hand, we know, and the on the other hand, we don't know very much also, it's very funny. But like, let's say proper fall, for example, it's just like a GABA agonist, so works on the inhibitory neurotransmitter and just generally inhibits like neural activity across the board. More specifically, it's so interesting, we actually don't know very much also the the the mechanisms of anesthetics, we just know they work, they work also not in humans only, they work even on plants, which is kind of surprising to me. um So yeah, so There are other kinds of anesthetics that that um you've we've looked at or thought about for that there might be dreams de occurring. Are those also similar GABA agonist type anesthetics? Except ketamine. But ketamine is known to be like a glutamate agonist and ketamine of course
00:17:52
Speaker
produces hallucinations also, you know, in the waking state, is it associated? So it's it's a different mechanism. And of course, you can get dreams with ketamine as well. So it's not like only this mechanism, right? And of course, and what otherwise you can, so we are arguing that it's not specific to the anesthetic, even though they might have ah different mechanisms. um But we can, we're able to get this dreaming state across different aesthetic and other stuff shown that too.
00:18:19
Speaker
And then you know the a big part of this work is the idea that these types of dreams might have some therapeutic beneficial effects, particularly in, for example, patients who have post-traumatic stress disorder. I'd be curious to hear like, where did that idea come from in terms of just the idea that dreams might have some opportunities for therapeutic benefit? And then, yeah, just like where did that idea come from? where' is What's the the lineage there?
00:18:50
Speaker
um So I think there are two answers to this question. One is like generally the idea that when we don't talk about anesthesia per se, but like dreams, what is the function and the idea that maybe dreams themselves might have, well, might have or have not functioned. There's like debate about there. But if they have a function, and the idea that it might be somehow not only reflecting on mental health, but might be like beneficial, for example, they have like a whole bunch of emotion regulation theories.
00:19:15
Speaker
of dreaming, which suggests that dreams help process memories. So they kind of rely on the memory consolidation theories, which argue that, yes, during sleep and dreams, we process memories, but that this is beneficial for, let's say, down-regulating negative affect, negative emotions, and it's beneficial for waybook. Whether that's the case or not, there are studies testing that. I don't know about that particular, but that's to the anesthesia dreams. So really, it goes back to this. So why we are testing, so especially on PTSD,
00:19:43
Speaker
um, patients or symptoms is, so we had like, uh, just, uh, happened to come across, uh, certain patients, actually so far free patients who came to the surgery like they do for totally different reasons. And Dr. Harrison Chow was the anesthesiologist and he induced them dreaming state, or let's say the state pre-emergent state that is very likely to be associated with dreaming.
00:20:11
Speaker
and And these patients um all had like very powerful dreams. Now, what we kind of discovered right after they were there, they just came to surgery, but we found out that three of those patients, they had PTSD or acute stress disorder already while they kind came to surgery. One patient um had suffered a traumatic knife attack.
00:20:34
Speaker
So, so she was very traumatized by this attack, was not able to talk to anybody. That had happened two weeks before surgery. She was, you know, had nightmares. She was not able to sleep and not that you know afraid to talk about it. She came to the surgery. ah Dr. Harrison-Chalen induced the dream state. She had a dream where she was attacked by the knife. She went to the OR, but the dream continued at home. or She woke up from the nightmare, but they're doing anesthesia. The dream continued where she um the hand was repaired. She went home and was able to just normally do things. And when she woke up, she was like, wow, this was like the best sleep ever. And she was able to talk about the trauma. Her symptoms went away. She had no nightmares about this. And basically, it it's almost like
00:21:22
Speaker
this resolved the nightmare and with that the trauma.
Therapeutic Benefits and Case Studies
00:21:26
Speaker
And now very recently this year we published another case series with two patients who similarly had PTSD just coincidentally these two female women.
00:21:37
Speaker
had ah both lost their sons. So they were suffering trauma. It was a traumatic event for them. One woman lost her son due to suicide, the other due to alcohol poisoning. And that has happened years before. And because of that, they both had nightmares, PTSD, symptoms, depression, anxiety. So they came to surgery, again, total different reasons. ah They went through the anesthesia protocol developed by Dr. Harrison Chow.
00:22:04
Speaker
and then um We have been like now, together with, I mean, Dr. Boris Heifetz's lab. So Dr. Eisenhower contacted Boris Heifetz and we've been studying those patients. and And anyway, so these women, their anesthesia dreams were just um like basically euphoric they they said. So one woman dreamt that she was, she basically relived the birth of her son which originally had been very traumatic but in the dream it was like deeply joyful. She had also another dream where she saw the son running on the field with a dog, the dog that he could never have and she was very sad that he could never be with a dog but he saw the son there with the dog and for her it was like
00:22:44
Speaker
really such a relief so she of course when she emerged she was sad that it was just a dream but ah she kind of thanked the doctors and saying thank you for having given me this time like you know where you see your your son being happy right and that it's good and After that, she has basically has no PTSD symptom anymore. Anxiety, depression, her nightmares went away. and she This has been lasted, we are still in contact with her now almost two years. The other patient had also similarly um a dream where she was together with her son in this very warm, beautiful, light presence, a euphoric dream, and again also has not had symptoms of PTSD, ah depression, anxiety after that. so This is where we are coming from. so We have this case studies and
00:23:28
Speaker
And so that's kind of, oh, is it really that something that the anesthesia enables somehow process those traumatic memories in a way that provides relief and whether that would then somehow be helpful for their symptoms. Of course, in the surgical context, it's observational studies. We don't know. We need to test it. So now we are doing this. We took this stuff to the experimental setting and we're trying to test without any surgery, without any other drugs.
00:23:57
Speaker
is this the dreaming itself that enables to kind of like reduce symptoms of ah PTSD. And if it does, of course, other mental health issues possibly as well, but but that's what we're kind of just trying to figure out now.
00:24:12
Speaker
So this is really interesting stuff. um Do you relate this back to um some ideas about the function of dream, like threat simulation um theory, the idea that we may be reprocessing um um potentially dangerous situations and um able to resolve them, say, to our advantage um in dreams? So it's sort of like a practice space or something like that. Does that?
00:24:37
Speaker
seem like a framework for these kinds of results, that your or these kinds of um these kinds of dreams that you're talking about? Yeah, that's a good question. um I will quickly mention also Dr. Reimann Zuhu, who is the who who put forward this theory. He was my PhD supervisor, but oh, okay. But like, so I think there's this I would say that, so the Fred simulation theory is a very different type of dream theory, right? Like, it's like an evolutionary. It kind of doesn't argue so much about what the dreaming right now would be beneficial somehow for a waking world. It kind of just argues like, why kind of starts from the findings that dreams, like normal sleep dreams seem to be very negative um and a lot of threatening content. um And then why would that be the case? And then he has put forward that it's kind of evolutionarily
00:25:27
Speaker
um offers this kind of like virtual simulation space to go through the possible threats that we might encounter, especially in the you know earlier times in human history, where you know what threats you might encounter, so you can kind of safely, in your virtual simulator, practice those so that it's helpful. But what is important point here is that um It doesn't, the Fred simulation actually the is working very well when you have lots of bad dreams. And nightmares are actually a good example of very well-functioning Fred simulation. And actually it might be bad for your wellbeing because nightmare disorder is separate. So so in that sense, it's it's a theory that says why we have say negative dreams and what the function would be, even if it might be not so beneficial or adaptive toward everyday life. Whereas the motion regulation theories, which are different
00:26:15
Speaker
group of theories would argue that, hey, dreams actually are adaptive for a current, ah or if everything works, if whatever is the dreams are doing, they're able to down regulate the negative emotions and arousal, then that would be beneficial for a waking life. So in a way, they would explain why there's negative content, but like, on one hand, it would be adaptive now and the other would say no. so that i That totally makes sense. Yeah. um And that, and And that um makes sense for thinking about this just this really positive, especially positive affect that these people are having. You said euphoric affect that some of these people are having after these dreams too. Do you have any sense of what might be responsible for that that might be really causing a sort of really positive or or happy feeling during anesthesia?
00:27:06
Speaker
Yeah, it's a great point. Also something I forgot to mention perhaps before when we asked that, what are other dreams more like REM or non-REM dreams? That's one very big difference between anesthesia dreams and other dreams or normal dreams or whatever we call, because they are typically almost always pleasant. Not always necessarily euphoric, but like right now I'm just analyzing the data from more than 400 cases in and in the surgical setting. i see and you know 85% are positive right like and there's just a few otherwise and they're neutral or a few somewhat sad or whatever it is so that's a big difference so there's they are by default positive or pleasant experiences which is great right so what is the case i can only just hypothesize i don't know but i assume it's something to do with the anesthetics right that they kind of
00:27:52
Speaker
ah put us into this kind of low arousal state. Of course, they are not opioids. of You would expect that with opioids. But there are some studies that also show that maybe propofol has like some antidepressant de effect. it may be good Even though we argue that it's not specific to propofol, that we could get the same with other drugs. so It's just this kind of general low arousal state, I would say, that then then if you have experiences, it just happens on top of this more low arousal sympathetic arousal state where you don't have this It kind of, whatever you experience, it doesn't ever get to the level where you would have a nightmare type of scenario. Well, I can't say never because we still need to figure it out, but but that's the kind of working hyposis a working hypothesis is like, okay, that perhaps the the brain, ah we are able to reprocess some elements related to this traumatic memory or whatever people are worried or concerned about what's in the mind, but it's played on a kind of low arousal state. It's almost like reconsolidating these memories in a like,
00:28:52
Speaker
in this kind of lower also state and that might be helpful, but why they are pleasant and yeah, we need to figure that out more specifically. Along those same lines, are there things that you were trying to do to amplify or ensure that the effects are beneficial? So yeah just sort of increase the therapeutic benefit for patients when they're experiencing these types of dreams?
00:29:16
Speaker
Yeah, that's a great question. I think we're just so early starting here, trying to like make sure that we can induce the dream state and what are the correlates. And then, of course, what can we do? like Manipulating content is like the next question, right? like What should we do to actually induce more positive? Or do can we trigger particular dreams? And this is something we we we like would be the next step to figure out, like can we manipulate that? But right now, we're just trying to see whether we can do it in a consistent, reliable manner and what are the yeah underlying neural correlates and whether that would be beneficial. And then of course, the next question will be, if it is or if it isn't, can we trigger like some specific content type, like more pleasant or or anything like that? So yeah, right now I don't know the answer.
00:30:02
Speaker
ah so Do you think there's ah a relationship between the sort of therapeutic ah benefits of anesthetic dreaming and psychedelic therapies? Great question.
00:30:15
Speaker
so i was thinkinging toojo i was kinna so because Because I think that's exactly where we're thinking. that but if i Because I talk to these patients as well, the way they describe their anesthesia dream experience is, to me, it sounds really like as as if they have had um similar very similar when people describe their like transformative psychedelic experiences. like There's something profound and it changes the way they feel, they see the world, they they approach their life. So that's exactly what we're we're we're trying we're we're kind of framing it as. um
00:30:53
Speaker
But is it ah another method or way to produce transformative experiences? In one case, using psychedelics. In other case, perhaps we can use dreaming. But we don't know. we're we're Actually, we're also trying to like compare psychedelic experiences with these anesthesia dreams and other dreams to see like to what extent they're similar or different. but But that's basically, we are trying to go that road, yeah like thinking that it's just, especially now that there's so much work on psychedelics and their mental health benefits. And the question about to what extent is the role the experience as a role in that. And we're also i mean doing actually parallel studies on that too. At Boris Heifetz's lab, Dr. Boris Heifetz, his work is all on trying to understand the mechanisms of psilocybin, ketamine, MDMA, things like that. so So that's what we're trying to see is yeah whether we can actually use some other methods to induce similar type of experience, or at least that would have similar types of therapeutic effects.
00:31:52
Speaker
Well, that's that's very interesting. In terms of the neural correlates, you know a couple of the things that are mentioned frequently in psychedelic experiences are ah diminution of the default mode network and increases in brain entropy. Do you see either of those in anesthesia and anesthesia dreams?
00:32:13
Speaker
um I hope we will be able but to answer that question. We have tested that. So now we are just in the middle of collecting that data from ah using EEG. So then we are actually trying to look into the entropy measures as well and complexity of measures. In the long run, hopefully we'll be able to conduct some fMRI studies as well. ah There is a group in in Harvard and an NIH that also occurring out currently studying. They are using fMRI to study dreams, but they are just looking normal dreams. And they're what they just reported dream vividness seem to be associated with increased
00:32:58
Speaker
ah connectivity between PCC, posterior cingulate cortex, and sensory areas. But like, really, like I said, as these are dreaming, there's so little research that we just don't know yet, but hopefully we'll figure it out but very soon. Next time. I can't say something about that.
00:33:16
Speaker
That's great. So just a question about experimental design and and thinking about the experiments here. So you're going to be putting people through anesthesia. They're going to be having some dreams. Hopefully you're going to be getting some information about their dreams. You're going to look at whether they their mental health has gotten better. I guess the first question would be just like what kinds of measures are you interested in looking at in terms of improvements ah in mental health?
Can Anesthesia-Induced Dreams Reduce PTSD Symptoms?
00:33:42
Speaker
um So the study that we're just about to start, um PTSD patients, of course, we're especially focusing on symptoms of PTSD because that's our main outcome.
00:33:54
Speaker
um So we hope that we would see a reduction in PTSD symptoms in those who dream versus so those who do not dream, or at least a larger decrease. But also we track, of course, other aspects of mental ill-being, like symptoms of anxiety, depression. But in addition to that, we also look at aspects of wellbeing because you know mental health is not just the absence of mental illness symptoms, it's also the presence of mental wellbeing symptoms, if you like.
00:34:18
Speaker
um and we're tracking like different aspects of wellbeing at the same time. So we have actually a broad range of measures that assess aspects of but the main focus is currently in pds on PTSD.
00:34:30
Speaker
Great. So that makes a lot of sense. And I guess that relates to the the ah letter that you shared, the letter to the editor um that did show reductions in PTSD symptoms in those women that you mentioned, as well as reductions in anxiety and depression symptoms, ah which is which is really you know a great early result.
00:34:51
Speaker
how are you thinking about ah comparing that to something? like what What would be a comparator or or placebo kind of group for that, just to see that you know this is a function of the the dreaming per se or the anesthesia per se? or you know just how do you How do you think about that in general? just like what are the What are the relevant comparators?
00:35:10
Speaker
Yeah, so if we want to argue that it's specific to dreaming, right, then that should be the only thing that is manipulated rather than anesthesia or anything related to anesthesia. So what we are planning to do is to randomly assign participants into those who in whom both so all everybody goes through anesthesia, proper anesthesia,
00:35:32
Speaker
In one group, we'll try to use the protocol that most likely results in dream experiences, in the other group that doesn't result in dream experiences, and then measure the outcome. So the difference would be um not specific, hopefully, to to proper for let's say in this case, but dreaming. Of course, there are some differences then in in we would ideally we keep generally the dose or level of propovol same ideally and it's like the emergence speed but there might be of course some differences there but we would hope that it's not specific to propovol of course it could be that it's like let's say we find both get better or don't get better or let's say both get better and then we don't maybe know to what extent it's the propovol so we have been just discussing that another
00:36:17
Speaker
ways to um compare it to standard, like the best treatment right now, which is for nightmares, which is imagery rehearsal therapy. And then of course, like a weightless control would also be relevant. But the current idea is to just like start from the assumption that it's the dream and then compare, otherwise keeping it the same things the same, inducing the dream state versus not. And then looking whether there's what would be the differences in those two groups of patients.
00:36:43
Speaker
and makes a lot of sense. All right. Well, what what are this is really interesting research. It's so just cutting edge, really interesting like next level stuff. i'm i'm This is great. where where where you Where do you think it goes from here? like What are you excited about in terms of where this research goes next? like What what like yeah gets you fired up? um I mean, first of all, it is already super exciting. I think realizing that actually- But people already dream, like, I mean, many people are actually shocked to hear how much people dream during anesthesia and that's already new. And then, so first of all, like, can if if that would be possible, we could have like a whole new treatment for maybe not only PTSD, but for other conditions, right? We we don't know yet, but like if it is. ah Additionally, from that kind of more practical clinical perspective, I mean, if it is a pleasant experience and it's beneficial, then,
00:37:44
Speaker
How many millions of surgeries are happening all the time everywhere? Like changing a little bit of surgical, let's say not surgical practice, but the practice where we don't kick out people who are immediately when it's over, but give like five minutes extra time. If that is beneficial for, you know, the recovery or how they feel, even just if they feel better, the mood, like they're more aroused.
00:38:04
Speaker
I mean that's huge if you think like changing some kind of like clinical but practice aspect and of course as a consciousness researcher um you know if we would figure out what are the neural correlates of dreams or the experiences irrespective of what state we are in of course that hopefully will lead us one step closer to understanding the neural correlates
Future of Dreams and Consciousness Research
00:38:25
Speaker
of experiences. One day as I said I'm still still the same idea I had like a long, long time ago, where it's like, can we one day, you know, just measure the brain and see if somebody's having any experiences at all and what these experiences are. um Yeah, and and and and all kinds of, yeah, I think that's like my main main thoughts, which I think is super exciting. Yeah, that's that's that's awesome. That's a really exciting line of research.
00:38:52
Speaker
but I have another another question that i've I've been dying to ask too. And we've been talking about some specific dreams where there's a real world um sort of therapeutic thing happening um so that theyre they're relating those dreams to something in real life. And it's always been sort of tricky to figure out what the relation the relation is between real life experiences and content and dreams. How do you see what ends up making it into dreams? Does it Is it ah is it relatively random, a random assortment of memories? Or is there some structure we could say about, you know, ah how and maybe important things from our our life, you know, as what Freud said de residue makes it into into our dreaming life? That's a great question. agan So there is like, of course, a lot of research on not trying to understand what
00:39:48
Speaker
why certain things appear more likely in dreams and not others. There's like the so-called continuity theories. Actually, there are two types of continuity theories. One would argue that dreams just reflect our experiences, whatever has happened to us events, but that's kind of quite not specific about what, why some type of content is more likely to appear in these others. Then there is the continuity theory kind of framed by Domhoff, William Domhoff, where it's like, especially personal concerns um that um appear in dreams, like things that you're worried about. So I think, and then other research studies which seem to indicate that the more emotionally intense, and salient events, more emotionally salient experiences are more likely to appear because they're relevant for us. So like, we don't dream very often about writing or working behind a computer or like stuff like that. It's more,
00:40:39
Speaker
but if there's a worry about something going wrong or, I don't know, you were talking about being late for the exam or or not knowing what to do or things like that, then that's like the concerns that are important for your brain, I guess, to remember. If we think that that that's what is going on, it's kind of like trying to sort through what is necessary to remember and this kind of gets selected, perhaps to to process and <unk> decide what gets stored, what doesn't, and whether dreams are just reflecting that process or are fundamentally involved in that process. That's of course an open question, but but there seems to be emotionally salient events.
00:41:13
Speaker
that most likely occur. And of course, the day residue, there is evidence for that, that most recent, but also there is like um a dream lag effect, which shows that items like seven days a week ago, kind of are more likely to appear, which probably says something about the memory consolidation processes occurring or memory processing. But also of course, we dream very much often about like childhood stuff or somehow it's combined with with current things. and And again, I think it reflects that kind of memory processing. But basically I think the answer would,
00:41:42
Speaker
most likely to be like the more emotionally salient relevant concerning things to us are more likely to be selected ah for um for processing and also for like appearing dreams.
00:41:55
Speaker
Yeah, and I mean, I think maybe there's a temptation to to sort of appeal to the freud that Freudian idea that there's kind of an act of unconscious that's selecting things for you, almost like a second mind inside your mind that's deciding this stuff is important and and um and then actively disguising it in some sort of way. So this sounds like a less some laden version of that of that way of thinking, not not not necessarily attached to any act of unconscious doing anything, but um that emotionally salient events might um might be activated, but not through some sort of conscious agent or unconscious agent. Yeah, that's an interesting idea and connection.
00:42:42
Speaker
Well, great. Hillary, maybe that might be a good ah place to stop, ah you know, conscious of of the time here. We really appreciate your coming on the show. And yeah, really interesting, really, really interesting research. And yeah, great to talk to you. We'd love to have you back again when ah you've got some more more data and some more findings to discuss. And yeah, just love to follow the story.
00:43:06
Speaker
Thank you so much. It's been pleasure, really. I love to talk about dreams. I'm so happy to talk about them.
00:43:17
Speaker
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00:43:35
Speaker
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