Welcome to stot to Blow Your Mind production of My Heart Radio. Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lamb and I'm Joe McCormick, and we're back with another closet edition. Uh So this week we got kind of hijacked off on the side trail that we didn't quite expect at the beginning of this week because of a personal experience you had, right, Robert, Yeah, this this would have happened Wednesday, and it's got me researching some other topics and looking into it, and I mentioned it to you and the next thing we know, we were putting notes together for a couple of episodes. But it's great because this is also a topic. It gets into some topics that have been requested by listeners as well. So Lenny said, a little background for for what I'm about to describe. So give us your origin story. Yeah, my origin story, such as it as it is. When I was a kid, maybe seven or eight years old, which is which is uh the age of my own son today, I had a very vivid and unsettling mental experience. It wasn't really a nightmare, but much like a nightmare, there was this ineffable quality to it. You know, like even as I try to explain it, uh, my words can't really relate how it made me feel and how it still makes me feel. Like when I when I remember it, when I think back on it, I can still feel a bit of the terror that I felt then. Uh, even though just a flat description of it sounds kind of dumb. Yeah, that's often how nightmares are. It's like the thing that was really scary in your dream wouldn't necessarily make a good horror movie because it's hard to communicate why it was scary. Yeah, exactly, Like I once had a nightmare about a polar bear that was peeking into a house with a periscope, and somehow that was terrifying in the dream, but outside of the dream, it's just ridiculous and comical. So uh, but this particular situation, it was, it was not a nightmare. Um, I was in my bed and I have always slept with white noise, so even then I had this like oversized box fan in my my childhood room. And I should also explain that I watched a lot of TV in those days, and the you know, my family would watch TV together and there were various shows on TBS that we would regularly check out, and one of them was the sitcom Sanford and Son. You remember Sanford and Son, right, Oh yeah, totally yeah, Red Fox uh uh so uh. You know, I don't want to use the verb here or heard here, because it's it's not like I actually heard sound. It's not like I experienced an auditory hallucination. It's more that I suddenly remembered it as I lay there in bed. It was like a jagged memory that was suddenly embedded in my my psyche. And it was the sound of the Sanford and Son character Fred Sanford speaking in slow motion through the back of a box fan, addressing the character Grady in this drawn out, oscillating voice. So that's great because that that has that perfect quality of something that would be terrifying in like a dream like memory, but you just can't see it from the outside. It's like I had a horrifying dream about Bob Sagett from Full House. Yeah, it's I mean, it's just so ridiculously dumb, Like if I were to to fictionalize it even a little bit, I feel like I'd want to change it completely, you know. Um, but but but the thing is like, it definitely filled me with terror, and I can I can remember that terror, and I can. I can really compare it only to the stark sort of terror that one feels in a nightmare, you know, especially with the nonsensical elements to it. And uh and indeed it also it did not feel like I was remembering something specifically from watching TV. And it didn't feel like I was dreaming. I it was, I guess, in some ways, like I was remembering a dream that I had never had. But in the sensation passed, the anxiety of it passed, although I I've always been able to feel like a tinge of it when I think back on the experience. So I've never I was never really sure what it was exactly. I kind of always just sort of thought, well, okay, it was, you know, something like a dream or a nightmare. I don't know. Um. And and looking back, I think there perhaps times in my life where I had like similar experiences in the years after that, but but pretty you know, far flung from each other, far less intense. And because of these factors, I've never really connected those experiences with this childhood experience. You know, when I think about experiences like that, especially involving lying in bed as a child. I think one thing that's often going on there is that in our memories we are having a hard time sorting the demarcation line between wakefulness and sleep. Um. And this is definitely characteristic of memories I have as a child, Like there are things that I feel like I remember as happening while I was lying in bed awake as a kid, But in fact I think they probably were some sort of like you know, edge of sleep hallucination, hypnogogic or hypnopompic hallucination, uh, dreams bleeding over into wakefulness. But that it's it's hard to sort out what's what at that age. Yeah, And I would say, prior to this week, if you really put me to task on on what that experience was I had as a kid, I would have probably leaned on on the you know, hypnogogic explanation of for what was happening. You know, like I was somewhere between wakefulness and sleep, and therefore my mind was susceptible to this kind of semi paranormal experience. And these kind of experiences are super common, by the way. That's nothing especially like pathological about them, right, Yeah, So you know, I also don't want to make it sound like this like shaped me as an experience, you know. S Yeah, like I continue to watch Sanford the Sun after it. Clearly it didn't. It didn't affect me in that capacity. No night terror can make Red Fox unfunny. Uh So so that was that was, you know, my life up until this week, uh, Wednesday, March. I then experienced what we're basically four of these in a single day. So I can I can kind of explain two of them, I guess. Um. So I've been I've been obsessed with Peter Lori this week, you know, the famed actor. Um. And I've been feeding that obsession, you know, to try and get my mind off of more stressful matters. And I was in the in the process of actually responding to an email to you, Joe about we had a slight sort back and forth about the ninety six movie Mad Love, which I have not seen, but I've been meaning to see for years because it has one of the best trailers of all time, Like the the two minute long trailer for this movie is more entertaining than most entire movies. It's got Peter Lorie sitting on the couch at his house and he's got this giant dog next to him, this bigger than he is. And then he gets a phone call from beautiful actress to like tell him what a wonderful actor he is. And then he starts explaining the new movie he's in, and it's Mad Love the movie that this is a trailer or fo yeah, and it's it's a wild movie. Um, I feel like it doesn't. It doesn't. It's not remembered as well as it should be. It has so many bizarre elements in it. There's there's knife throwing, there's their hand transplants, there's tragic mad scientists love stories. We gotta come back and do this as a as a full movie episode sometime. It's got the line in the trailer, a poor peasant have conquered science. Why can't I conquer love? Yes, it's such a great moment. But but in our email, you specifically mentioned a face that Peter Lare makes when uh, when when a previous film is mentioned to him, And and it was weird. When I was about to respond to that, I was like gonna type, and then suddenly I had like this kind of like mash up in my head, like a memory of his face in that trailer, and then kind of this this the fact that Laura is deceased, I don't know, just kind of like as if they were kind of floating in my head. And I suddenly had this just this czar deja vou like experience that was like really overwhelming, and I had to I had to get up, and I had to go go lay down. And then uh, there was a just a little later in the day, I I had another experience like that. Again. I was at a computer. I was looking over some of the telescool activities that my son had done in Google classroom, and I was making sure that everything was checked off, and it was like checked off in two different places, and you know, this juggling act of like eight different learning apps. And then suddenly I have this jagged chunk of deja vu like mental energy that, um, though quite vague this time, felt like a fragment from some old TV show, maybe Carol Burnett or something. If I had to guess, but I but I really that would be just guessing and like reshaping the memory. But again it hit me so hard that I had to get up. I had to go into another room. I like, I could feel my um, it felt like a like an anxiety attack, and I had to I had to, I had to lay down for a little bit. And then in both of those cases when I when I laid down, there was kind of an echo of the initial experience where I had like kind of another one and um and and then I was fine. But it was really weird to to to experience that, especially having not really experienced anything like that since I was a kid. All right, So I'm trying to sort out the elements of what it is you're describing here. So you're saying that there was there was an element of like sudden onset overwhelming anxiety, but also uh, sort of some mental imagery and a feeling of deja vu, like familiarity with whatever thoughts were currently entering your mind. Is that it right? Yeah? And And while the first one, the one with Peter LORI did have I guess there was some sort of contemplation of death in there, I guess, And and so that one was a little loaded, but but the other one had no like nightmare imagery. It was just kind of like a bit of TV shrapnel. And actually I had I had one more last night where I was just making I was making a drink. I was like, like making us some sort of tiki cocktail, uh, standing in the same place they normally do, and then there was just some sort of nondescript image, uh that that that gave me a similar sensation, and that passed. So you've had So these are like multiple instances of deja vu like experience in the course of a couple of days. How common is that for you? Normally? Would you say that you have a feeling of deja vu? Maybe once a year more or less. It's an interesting question because it's a question that definitely comes up in some of the studies that we're gonna look at where they ask people how how many deja experiences do you have? Is it, you know, once a week, a couple of times a month. I'd be really hard pressed to say, because normally when I have deja vu, it is so mild and uninteresting. It's just kind of like, huh, that's a bit of deja vu, and then I move on, you know, like it's never like this. So I would if I would to to to take just a wild guess, I'd say maybe maybe, like once every couple of months. That that sounds about right for me. Maybe a little bit less frequently now for me. I one thing I've noticed, and this is going to line up absolutely with some of the research we look at later. I definitely feel like I got deja vu like experiences much more often when I was a young child. UM, when I was younger. I I think I may have actually mentioned this on the show before. I have one very specific instance of deja vu like feelings that stand out in my memory, UM, and it was when I was a kid. I don't remember what age, but you know, I was young enough to be playing out in the front yard with friends. I think we were like running around, chasing each other with sticks and stuff. And there was a low hanging branch that was coming off of a tree hanging over our front yard, and I guess I was distracted. I was looking back at a friend of mine or something, and I turned around and I ran into this low hanging branch and hit my face. I think I ended up getting a black eye from running into the branch. And right then I had this powerful sensation like this is all happened before. He was standing right there where he was and I was here and I ran into the branch, and it was this time of day, this time of year. And I never knew how to make sense of that when I was a kid, because like, I think I pretty quickly understood that, like, no, this has not actually happened before. I even as a child, I don't think I attached any kind of magical significance to it, Like I didn't think that I was clairvoyant or something. It was just very odd. I was like, why do I feel like this exact thing happened before when I know it didn't. Yeah, the the stat about it occurring more when you're younger definitely comes up, which, of course it doesn't really help me out explaining this because I'm what forty one now, and it seems like I should have had the bulk of this earlier on um. But but I mean that's just on average. I mean, everybody's different. Some people have it much more frequently than other people do. I'd say it's pretty rare for me now. I think I probably it at least a few times a year. Well after after I had these experiences, I I you know, I initially asked, well, what's a different right, That's what you you can always uh, you know, use trying to deduct right things that are that are different this week. Yeah, yeah, I mean, first of all, it's I thought, well, maybe there's this panicky aspect to it. Maybe I had two innch of coffee, but no, it's a usual amount of coffee for the day. I thought, maybe, you know, had something to do with steering at screens too much because I was working, you know, at my own laptop and then having to go in and help my son with his laptop. But I dismissed that pretty quickly as well, because it seems like the connection to some sort of anxiety was unavoidable. Because, you know, while while my family and I are objectively you know, lucky and fortunate compared to plenty of other people going through COVID nineteen, social distancing, shelter and place mandates or actual you know illness, there there are a lot of things to be anxious about right now. I mean, there's the pandemic itself, local individual, national response is to it, household protocols to stay safe, my son's tell us schooling, my own attempts to make my work function remotely, trying to follow the World Health Organization recommendations to only check the news once or twice a day, that sort of thing. Yeah, how's that going? I think I'm I'm still exceeding the recommended dosage of news per day, but it is helping me cut down a bit. Uh. And and like some of the times when I'll reach for my phone to look at the news, I will put it down instead. So I think that's it's some advice to take to heart. Yeah, I feel like looking up that stats, it's like looking up you know, like how many alcoholic drinks are you supposed to have a day. It's like yeah, uh, it's like maybe if you find yourself googling that, it's it's worth considering that you should consume less. Yeah, exactly. Um. Another another bit of of infoll throw out on the anxiety. Uh part of it is that I know on Wednesday I did go on a walk, but otherwise I didn't really leave my front porch or my house, and I ended up not doing yoga or any other kind of mindfulness exercise that day. Um, so that could have also been a factor. It's like, well, I did less to sort of get out of the default mode network and to escape panic that day. Uh. So maybe I was more susceptible to it. Yesterday I did do yoga um and only had one of these episodes. So uh, you know, again, I think that supports the idea that, well, there's something going on here with anxiety, right, And and to be sure, I can be an anxious person in the best of circumstances, and I've gone through, you know, some stressful times in my life without having any episodes like this before. But I thought, well, maybe this is kind of the accumulation of things, right, death by a thousand cuts. Right, There's just all these little things and some extra things to be anxious about, and it kind of builds up. Yeah, that kind of doesn't make sense for having anomalous I don't know types of mental phenomena. But then again, one thing that strikes me is interesting about this is that I don't formally associate deja vu like sensations with anxiety. Yeah. I had not really either, because again I didn't I had never really thought of of that experience for my childhood as being really connected to deja vu. But but after these, uh, these experiences on Wednesday, I started doing a few searches looking around, and indeed a quick glance around the internet for deja vu panic attacks indeed turned up some hits like there was someone on an epilepsy website with a post titled deja Vu slash panic attacks very tired of being undiagnosed. Another health board nightmarish deja vu and anxiety attacks. What's going on? Um? And in both of these posts people responding with like, yeah, I get this too. Uh, I hate it when this happens, that sort of thing. And granted, we're talking about message boards where people are, you know, engaging in varying degrees of self self diagnosis, et cetera. But it was enough to make me think, well, maybe there is more to this. And and uh, you know, I I've never really researched deja vu itself all that much, so I should look a little deeper. So in these episodes, that's what we thought we'd do. We take a little time to explore deja vu and to explore the connection between deja vu and anxiety and deja vu and dreams. All right, well, then maybe we should take a quick break and then when we come back, we can dive into the memory fog. Thank thank alright, we're back deja vu. Uh, a term that I guess most people are familiar with, but you might not. You might not necessarily be able to define it off the top of your head. Um, you should probably just talk about what it means, right, So deja vu comes from the French. It literally means already seen. Uh. Now, there are actually a number of different terms for similar, overlapping experiences that often kind of get blended together and blurred together. For example, there's another term that's sometimes used. It's deja vit coup, which means already lived. And so there's like a lot of things that we call old deja vu meaning already seen or probably you know, probably could be categorized as deja viku, meaning like I've already been through this situation or I've already lived at this moment. Yeah, they're they're about like twenty different variations of this and uh and I'll get to some more of them in the second episode of this series. Yes, But basically, whatever it is, deja vu, deja viku, uh, it means that you are having some kind of experience of a stimulus. You're looking at something, you're hearing something, you're feeling something, you're going through a situation, and you suddenly get the feeling that this has already happened. I've already seen that, or I've already been here, this has happened sometime in my past, despite evidence to the contrary that like, you're not seeing something you've already seen, you're not living through a moment that has already happened. I feel very confident that, you know, in my in my experience as a child, that I had not already been playing with those same friends and run into a branch and gotten a black eye and all that. For some reason I felt like I had. Yeah. Likewise, my childhood experience was it was again not that the feeling that there was an actual voice in the room with me. It wasn't It wasn't like that. It was just this feeling that, you know, the terror was associated with the fact that I didn't understand like what the sensation came from, not that it was real. I guess with your original sensation as a child. There's another level of complexity though, and that'll get into stuff we'll talk about more in the second episode, with ideas like de jaureev which do you like that? How I said that French word? Oh yeah, you hit the fresh nicely on that, which means already dreamed. So like there are some cases where you're not even experiencing real external stimuli. You know, it would be like I already had this experience as a dream. But then maybe the current experience isn't is just an imaginative moment. So it can get very complicated in meta um. But I mean, especially since just the the vast differences that are possible from from brain to brain, from mind to mind. Um, That's kind of the sense I get from a lot of this research is that when you're dealing with the basic broad deja vu experience, uh, you know, one size is not gonna fit all. Like, it seems like it's going to be a slightly different experience, slightly different frequency, depending on the individual and the current state of the individual. Right, I would maybe categorize all of this stuff under an umbrella that we could just call anomalous familiarity, a sense of familiarity with something that you have no reason to be familiar with. So credit for the term deja vu is usually given to a French philosopher, writer, and parapsychologist named Amil warrock Uh. He used the term in a letter to the editor of an academic journal in eighteen seventy six. Though I do not think Barak made a distinction from what I can tell, between deja vu is like a normal psychological phenomenon versus the supposed psychic power of clairvoyants. And this is something that comes up a bit throughout the history of research on deja vu. Um. I think it's more recently that deja vu has been has gotten a lot of attention as a like just serious subjective phenomenon, as opposed to people looking at it trying to find evidence that it's like literal precognition. It's weird, isn't that. This this kind of idea about deja vu is really reflected in the Matrix movies, remember where uh, if you see a black cat twice or whatever, it's just a glitch in the matrix and it's not really treated. It's not really a major plot point. It's just kind of like, huh, isn't that interesting? Uh? Nothing, you should waste your time with neo just to keep keep on course. Well, you could look at that two different ways. You could look at that as like, oh, it's just a little thing, or you could also look at it as at least in the Matrix movies, it is giving you real information about the external world. And oh, and one thing that we will come back too is there are some theories of deja vu in which the experience of deja vu is giving you some real information about the external world. But it's not clairvoyant or precognitive. You're not having the sensation because you actually saw the future from the past. It's more likely having to do with the brains straining to connect memories that that may not be exactly how they feel. Yeah, but one thing that I found was interesting is that before it was fully described and named in the clinical or scientific context, deja vu was observed by a number of authors and poets throughout history. Yeah. I was reading a little bit about this from the deja vu researcher Art Funk. Howser will come back to some of his some of some work that he was involved with the paper that he was a co author on. Yeah, a little bit later. Uh, but but he pointed out a few different early examples. Uh. One of the earliest, I think the earliest that he identified, Well, he's pointing to the writings of St. Augustine, but to understand what Augustine's critiquing. You have to go back to the Roman poem uh Avid, who lived forty three b C. Through seventeen C. So Avid had written about the human soul is a thing quote deathless and ever quote when they have left their former seat, do they live in new abodes and dwell in the bodies that have received them? So all of it is getting into ideas of precognition and more specifically the survival of the human soul. So a. It is not talking about deja vu here, but what he's talking about like basically the idea of reincarnation, about the soul passing from one life to the next. Uh So, three hundred years later, St. Augustine is critiquing of its words and he writes the following quote for we must not acquiesce in their story. Who assert that as Samian Pythagoras recollected some things which he experienced when he was previously here in another body, and others that they experienced something of the same sort in their minds. But it may be conjectured that these were untrue recollections, such as we commonly experience in sleep when we fancy we remember, as though we had done it or seen it what we never did or saw at all, And that the minds of these persons, even though awake, were affected in this way at the suggestion of malignant and deep deceitful spirits whose care it is to confirm or to sow some false belief concerning the changes of souls in order to deceive men. And that is from Augustine's on the Trinity. Uh so, so basically he's he's saying, okay, of it is, uh, you know, don't listen of it because he might just be talking about this thing that we have all have some experience with. And funk howser saying that that Augustine is is probably talking about deja vu. Here. Yeah, I found another great example by the British poet Alfred Lord Tennyson, who wrote a poem around eighteen thirty three or eighteen thirty four called The Two Voices. Uh. This poem was written during a period of just deep misery and despair for Tennyson. The basic form it takes is of an internal argument between two parts of himself about whether or not to commit suicide, which he describes saying, quote, pain rises up old pleasures Paul, there is one remedy for it all. It's actually very similar in many ways to the famous to be or Not to be soliloquy from hamlet Um. It's certainly one of Tennyson's darkest works, but there's a lot of strange beauty and insight in this passage where he discusses the sensation of false memory, which did not yet have the name deja vu h. So Tennyson writes much more, if first I floated free as naked essence, must I be incompetent of memory for memory dealing but with time and he with matter? Could she climb beyond her own material prime? Moreover, something is or seems that touches me with mystic gleams, like glimpses of forgotten dreams, of something felt like something here, of something done I know not where such has no language. May declare that's nice. I also I am. I don't know if I'm alone here, but I feel like you could probably drop a beat behind Tennyson and it would have some serious flow to it. There's another one from British poetry that I found. It's kind of on a happier occasion, though it's by Samuel Taylor Coleridge, and he manages to take the happy occasion of a poem and and go in very dark places with it. But anyway, this is from a sonnet by Cole Ridge called composed on a journey homeward, the author having received intelligence of the birth of a son. He begins by about it exactly, I love it, But he writes, um off to or my brain does that strange fancy roll which makes the present while the flash doth last seem a mere semblance of some unknown past. And then one more. Charles Dickens writes about it in pretty straightforwardly in in his novel David Copperfield, he writes, we have all some experience of a feeling which comes over us occasionally, of what we are saying and doing having been said or done before in a remote time, of our having been surrounded dim ages ago by the same faces, objects and circumstances, of our knowing perfectly what will be said next, as if we suddenly remembered it. I like the part about dim ages ago because I think that is also a very consistent and interesting feature of deja vu experiences, at least in my life, and as I've often read about them is so you have the incorrect sensation of remembering present events or present stimuli from the past, but you can't place it. So you don't think like I had an experience like this four months ago, or you know, I had an experience like this two years ago. It's more like it had been in this inaccessible, kind of vague other time, which I think maybe the reason that a lot of people chalk this up to memory of past lives. Yeah, you can definitely see where if you wanted to believe in past lives, this is the sort of the sort of stuff you could turn to and sort of you know, warp into evidence. Um now, Yeah, And indeed, most examples that that I mean I've experienced. I think all the examples I've experienced have that vagueness to them, and you do see that in most of the reporting. However, when we eventually turned to the link between deja vu and dreams, there are some specific cases where people have a strong connection between like the deja vu experience they're having now in a specific dream that they remember. Um. So, I guess just a reminder that, yeah, with with deja vu experiences, with this broad category of DejaVu experiences. There's there's a lot of variety and so there even though that the trend seems to be towards just you know, the things, the damn ages, there are occasions where it doesn't seem so dim to the person experiencing it, which is very interesting. It makes you wonder what's different about those cases. And we'll get into some of that probably in the second episode. Well, are you ready to jump into some basic facts and findings about deja vu from scientific research? Yeah, let's do it. Let's let's just start talking about what we know and what some of the theories are regarding the true nature of deja vu. All right, let us jump on this ghost train. Uh So, first thing is, occasional cases of deja vu are very common for neurologically typical people. Deja vu as I think we alluded to this earlier, but it does not typically a sign of any kind of known pathology. It's just pretty common for people to experience it. Approximately sixty percent of people report having experience to deja vu at some point. Yeah, we're we're of course going to hear a lot from listeners about their particular experience with deja vu. And I just want to mind you if you have not if you were one of these, uh, these people that have not experienced deja vu at some point in your life, I want to know about that. I want to hear what that's like, and then how and how you process other people's reportings of of deja Yeah, that's interesting. I wonder if I guess it's fairly straightforward to explain, so you could know what it was, but you might not be able to understand how it feels if you've never felt it, even though you could. I mean, somebody can explain to you, like what the frequency of light of the color red is, but you might not really be able to understand it if you've never been able to see red. Yeah, because uh, deja vu in particular, My take on it is that it it feels at least casually weird. You know, every time it happens, it is at least notable for a second where like huh, well that's that's odd, and then then you move on. Well, No, I do think that's interesting because to me, deja vu feels inherently weird. It's just weird because you realize that it couldn't be correct, Like, it's not just weird because you logically recognize the misperception. For me, deja vu feels weird the moment you experience it, before you even realize anything's wrong. It is accompanied by a strange sensation. See that that's interesting because it makes me think of But between the two of us, like your, your typical deja vu experience might be maybe more intense or at least, uh, you end up contemplating it more I don't know than than I do. Uh. And then of course the episodes like I've had this week are certainly more pronounced than than either of these cases. So I don't know. But when when I experience like just typical deja vu, it is, it is generally just so casual that I might mention it if I am, you know, if i'm you know, around somebody that I'm close to, But otherwise it's just it's like seeing a bird flyover that's fun, like, oh, well, there's another bird. I'm not going to point it out because it's not a special bird, it's just another bird. Well, maybe this is another thing for listeners to tell us about. Oh yeah, I would love to hear from them, so we know it happens every now and then at least pretty frequently to even typical otherwise healthy people. But is there any psychological or neurological condition consistently associated with deja vu? I would say the answer to this is um. The actual evidence for the link might be a little more tenuous than has sometimes been suggested, But in the history of research on deja vu, there appears to be one major answer here, and that is temporal lobe epilepsy or t l E. So, temporal lobe epilepsy is characterized by focal seizures that begin in the temporal lobe of the brain. And the temporal lobe is very important. It's a crucial part of the brain that's been associated with major brain functions like emotional association, visual and short term memory. Does a lot of stuff with memory, like understanding and processing language. There's a lot that goes on there. So where does the deja Vu come in? Are people with temporal lobe epilepsy just more likely to have deja vu experiences? The answer there is no. Instead, there is a specific case where people with temporal lobe epilepsy tend to report deja vu, and that is in what's known as the aura before the onset of a seizure, so people with recurrent seizures often get this weird combination of feelings right before seizure happens. It's it's sometimes described as a kind of like series of warning signs. So these might include sudden, unexpected emotions like you have elation or fear with no cause. Another one might be numbness in parts of the body, weird smells or tastes from out of nowhere, like I smell oranges. Another one is known as epigastric phenomena. This refers to a weird feeling in the abdomen. I've read it some times described as a rising feeling, like when you're plummeting on a roller coaster. Um epigastric specifically, I think, refers to higher up on the abdomen, so very often it's like right below the chest, above the stomach, you know, right sort of where your solo plexus is. But then finally, another recognized symptom of of the aura for temporal lobe epilepsy is deja vu, which is interesting, right, yeah, because this this makes us look to causes in the brain, like like more specifically, it's it's it seems like there must be some sort of uh in neurophysical origin for what is occurring. Yes, But on the other hand, I think we should also acknowledge that deja vu is, as we've said, pretty common in people with no otherwise identified medical or neurological conditions. Um. And I want to quote now from somebody I'm going to be referring to a lot throughout this couple of episodes. This is Alan S. Brown, who published a big review of of deja vous research in two thousand three in the journal Psychological Bulletin. And this is an older paper and we will have to refer to some more recent ones to supplement it, but up to that point, it's a really fantastic review of all the research leading up to the early two thousands. Uh. And So Brown writes about the association between temporal lobe epilepsy and deja vu that despite the fact that it is a recognized symptom of a t L a seizure on set, deja vu doesn't appear to be more common in general in people with epilepsy. Quote. The weight of evidence argues against deja vu being more common in people with epilepsy or being diagnostic of seizure pathology. So there's a couple of things to weigh. They're on one hand, it is a recognized feature that a lot of people report when they're about to have a temporal lobe epileptic seizure. But on the other hand, it doesn't appear that people with temporal lobe epilepsy have deja vu more often than people in general. And uh yeah, And for for that to make sense, I have to do is just think back to some of these other symptoms uh we were listing, uh that are part of the TLA. Like, none of these other symptoms are things that are exclusive to people that are experiencing uh, epileptic seizures or anything. Uh So it's just deja vu is thrown in the mix, but it's not exclusive to people with this condition, right uh now, deja vu appears to be that this is one that that does look pretty solid in in the research. It is associated with stress and fatigue. You are more likely to have an episode of deja vu when you are tired and when you are agitated and you've got your stress hormones you're pumping your no adrenaline and cortisol. And this is interesting because I wonder how I mean it's not exactly the same thing as Robert. You're talking about your experience with UH sudden anxiety producing episodes of deja vu. But it makes me wonder if there's some kind of connection here. Yeah, I mean, when I ran across the same information, I I lined it up with what I had experienced, and Okay, you know, obviously there's the stress level, which I've already touched on, but also, um, all the experiences I had were in the afternoon or the early evening. They were not in the morning. You know, I did not experience them like when I in the first few hours after waking up or anything like that. So it's possible that, yeah, I'm throughout the day, I'm getting getting more tired, I'm having you know, I have less energy to handle sort of the ambient stress that is around me and UH, and that could potentially have some connection to the deja vu H like experiences that I had. Yeah, totally. Now, the next thing that I thought was interesting is that Brown reports that some studies have found that people who travel experience deja vu more than people who don't. For example, I was looking at the paper by Richardson and Winnaker from nineteen sixty seven. It was summarizing an earlier study by Chapman and Mench from nineteen fifty two. But this study had defined travel as going more than fifty miles away from home, and it reported findings that quote, non travelers experienced deja vu in only eleven per cent of their number, and in those who traveled twenty five percent of their number. There was no relationship with the frequency of travel. And so that part about no relationship with the frequency of travel makes me wonder, like, why would it be that people who like if this effect is real, why would it be that people who travel some have more deja vu than people who don't travel at all. But if you travel a lot, you don't appear to have it much more than people who travel a little. Well, well, the I guess the main potential answer that comes to my mind is that if we're thinking about deja vu as this experience by the novel seems familiar, if something new seems like something old, then perhaps there would be more potential to experience it if you live the sort of life in general, uh, either via travel or you know, via other acts that line up with this personality type. Uh. You know, the more novelty in your life, the more potential there is to then have that turn around and be made a seemingly mundane through deja vu. Oh yeah, well no, I've actually seen that hypothesized by a researcher who who I think we're going to talk about more later and Cleary who's done work on on deja vu. But I think I also saw her mention at some point that there's some research indicating that people who watch more movies are also more likely to experience higher deja vu frequency. Interesting now, now one I have to catch myself though at the same time, because when I think back about deja vu experiences I've had in the past, a lot of them have not They have not occurred while I'm traveling. They occurred like if I'm if they're occurring during novel experiences, they're only mildly novel, you know, like, oh, like I've never maybe I've never stood in my backyard with a coffee mug, you know, at this particular spot before. But that's hardly on par with say, traveling you know, around the world to to Bangkok or something. I was sailing to Byzantium. Yeah, um it was. So there's an interesting thing that Alan Brown notes in his review, combining the last couple of facts, the idea that deja vu appears to be strongly associated with stress and fatigue and the association with with travel um He he notes that there it was at least one clinician in the nineteen fifties who observed that reports of deja vu were especially common among soldiers heading into battle. Weird, but it would combine those things, right, Heading into battle tends to combine stress, fatigue, and travel into new locations. Yeah, yeah, you're really piling those up. Yeah. Now there's another one, which is that frequency of deja vu experience also shows a positive relationship with socioeconomic status and level of education. On average, people who are wealthier and people who have attained higher levels of education experience more frequency of deja vu, or at least report more frequency of deja vu on average, And that does complicate some other findings by the way, Like for I think Brown actually mentions, I wonder if like this is acting on the travel variable, right, that, like, people who have more money or probably more likely to travel more frequently, So something could be going on there. Yeah, And of course it also makes me wonder about the populations that are polled for these kind of studies. You know, um, I know that there's going to be at least one study later on that that the researchers point out that, well, we we looked at like four people, but they were mostly psychology students, you know, so common with psychology research. So yeah, not to because I don't know the particulars of the data that they're referring to here. You know, perhaps the polling data is uh is the survey data is more robust than I'm giving it credit to. But I mean, obviously that's always a potential problem when you're when you're considering information like this. Absolutely another thing I thought this was interesting. Men and women seem to experience deja vu at about the same rate. There have been a few studies here and there that found gender differences, but they were not directionally consistent, and combining all the results together did not find any differences for gender. Now, we've talked about overlap with neurological conditions, but here's one that should be very interesting. What about drugs. Do do any drugs cause increased uh chances of deja vou? Well, there are some isolated reports of certain drugs yes and causing very frequent episodes of dejav For example, I was looking at a paper from the Journal of Clinical Neuroscience in two thousand one where authors A. Tarot timon In and Satu K. Jones Yaskalainen. I think UH report the case of quote a thirty nine year old Caucasian, healthy male physician who developed intense recurrent deja vu experiences within twenty four hours of initiating concommitant UH. And this is a couple of drugs. I'll try the names here, amantadine and UH phenal propanelamine UH. Those are treatments against influenza. So the day he was started taking these two drugs at the same time, amantadine and phenal propanelamine and UH, and then the deja vu experiences stopped as soon as he stopped taking the medication. Now, amantadine is a drug that has multiple effects. It's used to promote dopamine in patients with some neurological conditions I think, like Parkinson's disease, but it's also used as an anti viral against influenza type A. Meanwhile, phenal propanelamine is a decongestion that is sometimes used as a cough and cold medicine. Um and I should note I also found at least one other case report from the nineties of psychosis in an otherwise healthy patient brought on by this exact same drug combination. So this appears to be related to the ability of these drugs to mess around with your dopamine levels. But we don't know for sure. And I must say that that would be such a strange symptom to report to your doctor. You know, they say take two and call me in the morning, and you call her back and say, Doc, I am I am experiencing deja vu every five minutes. Yeah, I mean, that would that would be something. But again, I mean there are other medications that have, you know, weird side effects like this. There's a there's a particular malaria treatment. I remember. I remember being on vacation and chatting with another couple that was on vacation, but I believe this was in Costa Rica years and years ago, and the older couple we were talking to they were both on this, uh, this anti malarial medication. Uh, you know, it's just just in case. But they were talking about the vivid dreams they would have every night because of it. Yeah, it was. It was quite interesting. It makes me want to come back and do an episode on malaria drugs because there are some there's some interesting stories about UH side effects and complications that have occurred with some of them. Well, maybe we should take another quick break and the when we come back, we can discuss maybe the single most consistent finding in the literature on deja vu. Thank alright, we're back all right now. I think Brown actually notes this in his review that that probably the single most consistent finding in the literature on deja vu is that frequency of deja vu decreases with age. Isn't that strange? Like there there's a graph that's included in UH in Brown's paper here that shows UH like it takes average yearly experiences like the san of number number of yearly experiences people report. And I imagine that there must be a lot of guessing because if you're like us, we don't exactly remember, but you know people people are estimating, and you know, you look at it and people in there, like early twenties, there's this spike and that they're reporting somewhere between like two and a half and three UH experiences on average every year of deja vu. But it's it's sharply curves down. You're down to like one or a half by the time you're in your late thirties, and then people in their like sixties are reporting extremely little with the internet. You know, it's a good thing we did the episode. If we if we kept going, you and I are just going to get older and older and we'll have fewer fresh memories of deja vu to talk about. Oh, we just got to keep our stress and fatigue up and then we can buck the trend. You know. Now here's another big trend about deja vu experiences that we see reflected in you know all a lot of these different variations of it, including it's what is often held up is its opposite Jimmy's oh yeah, and that means uh, something like never seen. It's the inverse it would be, uh, you know, deja vu is you see something new and you think I've seen this before. Jama vu is you see something you should be familiar with and you think it's brand new, You've never seen it before. Well, well, one of the an attribute that one tends to encounter in all of these experiences is that people with intact reality testing do not have a problem identifying the deja vu as inherently unreal. And this comes back to something we were talking about with our own experiences, you know, like even these really pronounced experiences I had yesterday, even the experience I had as a as a kid, like my my brain kind of fact checked them and said, is this real? Is there really? Is Fred Stanford really in my bedroom speaking through a fan? Uh No, he's not. This is something else, you know, yes, and that it's not. That's not a function of you being like a hyper skeptical person or something that that's like, that's normal for human brains. Yeah. So I was looking at reading around a little bit about reality testing, and according to the University of Adelaide philosophy professor Philip Grands, it's basically the system by which the brain monitors the brain's own storytelling system, the very narrative of our lives. So it ends up testing and rejecting ideas about reality. Now, I was running across uh, um, this is actually a two thousand and fourteen press release and or an interview that was published on Eureka Alerts and uh. In this, Grands used the example of wondering if a common headache is a brain tumor. Like you get a headache and you're like, oh boy, I've got a headache right now. I wonder if this is a brain tumor. Well, in a typical mind, this sort of thought is probably quickly rejected. You're like, no, this is just a normal headache. I had one of these last week and it wasn't you know, when't a brain tumor, then it's not a brain tumor. Today. It's nothing to get upset about. Okay. But but if one's reality testing is faulty, the notion that this might be a brain tumor, it might persist, It might even become more dominant, It might you know, become the thought itself becomes a malignancy. Uh So this, you know, faulty reality testing plays into various delusions, especially delusions that are tied to the way our brains process the familiar and the novel. And one of the examples that Grand's points to is cop cross delusion, which we've discussed in the show before. Yeah, Cap craws, where you believe that um that people you know have been replaced by doubles. So like you might see you know, it often results from a particular brain injury or neurodegenerative disease or something that um causes a dysfunction of the part of the brain that accused the feeling of familiarity when you recognize familiar faces. So you might see members of your family and you recognize them, you say, that looks just like dad. What you don't feel familiar and thus you think that's not him though, so you think that he's been replaced by a doppelganger or look alike. Yeah. So, so we can see that as kind of an extreme example of an illusion that's tied to malfunctioning reality testing. Uh and uh and deja vou is also an example of a mental experience that is subjected to reality testing in a typical brain, and indeed, it will generally fail a reality test even if it's distracting. Part of the distraction for us is generally realizing that it's not real. Like just this week, those experiences I had, like one of the super distracting things was that I realized that this wasn't you know, that this something was weird here that you know, it made me question the software, the hardware involved a little bit but it didn't make me think you know that, you know, mind flavors are sending thought beams into my brain or anything. Yeah, I mean this is generally an interesting question. How how the brain tells what's real? I mean, I feel like we we could do episode after episode on this subject. Actually, but like, like this came up not too long ago when we were talking about visual imagination. I think this was an episode from last summer. Um how there is evidence indicating that the brain uses some of the same infrastructure for imagining visual images that it uses for seeing with the eyes. And so if it does that, if there's stuff going on in the visual processing centers of the brain, just like when you actually look at a basketball, uh as when you imagine a basketball, how does your brain know that when you are imagining a basketball, you're not really seeing one. Clearly, there can be cases where that that reality testing fails. And this would be like you imagine seeing something and then you think it's really there. This is you know, I think what's generally accepted to happen in psychosis is like your your reality testing fails in the line between what is imagined and what is perceived as reality breaks and this of course, applies yet to dreams as well. Grant's pointed out that during dreams are reality testing is effectively switched off, so we simply have experiences. We don't have beliefs about experiences, which was interesting. I I don't think i'd ever you know, certainly we've covered dreams in the nature of dreams and thoughts about dreams in the show before, but I don't think I've ever heard it put so succinctly before. Yeah. Well, I think we have talked about the idea that in dreams, clearly critical thinking is reduced. Yes, yes, definitely that that seems to be an extremely common feature of dream cognition, and not just the kind of deliberate, effortful critical thinking that you do when you're like, okay, and I'm trying to understand is there a problem with this scientific claim or something. I mean, the normal automatic critical thinking that we do that forms the basis of our intuitive reality testing, even that is sort of turned off sometimes in dreams, or at least greatly diminished. Yeah, it's the kind of statement that makes me feel better about being such a horrible lucid dreamer. Not that I put in a lot of work on it. But I have frequently noticed that at times, the rare times where I feel like I could have lucid dreamed, I clearly didn't have it in me. Like I just fell right back into into just experiencing and certainly not having any beliefs or thoughts about the experience. This is so embarrassing. I'm such a dream loser. I've probably told you this before, but a very common experience I have in dreams is stopping in the middle of a dream and thinking, hold on a second, I'm dreaming right now, right is this a dream? And then in the dream I try to pursue that question and interrogate it, and then I, invariably every single time, end up concluding no, this is definitely real. Uh See, I've had I've probably shared this before too. I'll have experiences where I'm dreaming, I realized I'm dreaming, and then I just click it right back off again, and then I just fall right back into the dream. I had that moment where I was like raising my my head above the waters, and I could concede like that seems the time to take the reins of of the dream and and then engage in lucid dreaming. But I don't. I just fall right back underwater. This is funny. So we've got similar things going on, actually, except I just like I address it more head on and still fail. By the way, Grande is the author of the Measure of Madness, Philosophy and Cognitive Neuropsychiatry, which was published by m T Press if anybody wants to to look up more of their work. But uh, in general, though, just about the connection between deja vu and dreams, I guess it's gonna be the next episode of Stuff to Blow your mind where we'll definitely touch on on some studies related to that, but then we'll also get into really some of the core theories regarding that the true nature of deja vu itself. Yeah, next time we're gonna explore scientific theories that have tried to explain why the brain creates the feeling of deja vu, what comes from, and we'll look into dreams, we'll look into anxiety and more. I think it's gonna be very fun. Yeah, and certainly feel free to reach out to us in the meantime, knowing, of course that there's about to be another episode where we'll we'll probably answer some of your questions but hey, maybe not. Uh So it's always good to hear from you either way. In the meantime, if you want to check out other episodes to Stuff to Blow your Mind, you can find us wherever you find your podcasts, wherever that happens to be. Just support the show by rating, reviewing, and subscribing, uh though. That's the trinity of actions that help our show out. And if you just go to stuff to Blow your Mind dot com, that will shoot you to the I heart listing for our show where you can basically do all three of those things as well. Hughes. Thanks as always to our excellent audio producer Seth Nicholas Johnson, who, again I just want to emphasize, has been doing really heroic work while Robert and I and all of us are trying to work from home and do social distancing. Uh. Seth has helped us figure out all manner of gear stuff, closet stuff, and then today I couldn't even understand why my microphone wasn't working for the first half hour we tried this, So thank you, Seth. Thank you Seth. Uh. If you would like to get in touch with us with feedback on this episode or any other to suggest something for the future, or just to say Hi, let's know how you found out about the show, what's going on with you, whatever it is, you can email us at contact at Stuff to Blow your Mind dot com. Stuff to Blow Your Mind is production of I Heart Radio. For more podcasts for my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you're listening to your favorite shows.