Investigating neural effects during floating, Dr Joel Frohlich | 2022 Float Conference

okay [Music] so I'd like to start by asking how many of you have heard of a Theta state so if this concept sounds familiar please put your hand up and that looks like almost everybody and so if you've heard that floating induces a Theta State please keep your hand up and that also looks like almost everybody so I have some news that might surprise you a little bit I'm a neuroscientist but I myself don't know what a Theta state is and that's because Theta State isn't a term that neuroscientists use we do talk about something called Theta but we don't talk about a Theta state so to find out what a Theta state is supposed to be I went online and I consulted this wonderful resource of information known as urbandictionary.com and one of the first definitions I came across was by my father's princess which says the brain wave of being in a dream state where you can receive messages from other dimensions so this is a little bit of a Joe Rogan type definition and as you can imagine I was not completely satisfied with this so next I decide to ask artificial intelligence and as you may know there are now many AI programs that will take a text prompt and convert it into an image so I use the AI program mid-journey and I gave it the prompt what is the Theta state of consciousness and returned these images for me which as you can see completely explain everything so I'm fully enlightened now I get it I know what a Theta state is but getting slightly more serious let's take a neuroscience perspective on this so Theta is a wave or more technically a neural oscillation that occurs at four to eight cycles per second and it's important to emphasize that Theta is not a state meaning it's not exclusive to other neural oscillations and this next Point might surprise you but there's actually to date no reliable evidence linking floating to Theta activity now you all raised your hands and said you had heard that Theda is involved in um floating so where does this Association come from well for one there was this 1993 published report by Tom fine and colleagues which is one possible origin for this so this study ostensibly showed Theta and Alpha activity in a sample of nine volunteers during floating but there were some big problems with the study so for one it was not peer-reviewed it appeared as a published book chapter but not in a peer-reviewed scientific journal secondly there was no statistical analysis in the study there was no computerized measure of theta power and again this was a small sample of just nine volunteers so all of these factors mean that it's possible the authors might have succumbed a confirmation bias and seen what they were looking for right now to be fair to Tom fine my understanding is that he since acknowledged the limitations of the study and he probably never intended for it to start this term Theta state now whatever the origins of the state of State hypothesis are there's unfortunately a lot of misinformation about it online so just last month I accessed the Wikipedia article for sensory deprivation okay and you can see in highlighted text here there's a statement that doesn't have any reference so it says in the last 20 minutes of the float the last 20 minutes of the float often end with a transition from beta or Alpha brain waves to Theta now again there's no study cited here okay so there's no reference for this and unfortunately in this case Wikipedia just happens to be wrong now to be fair there are other reasons why we probably associate Theta with floating and one of those reasons is that there is evidence that Theta is linked to interdirected attention for example in the context of meditation and because many of us myself included choose to meditate in the float tank I think what's happened is we've made The Logical jump from Theta as associated with meditation which we have some evidence for to Theta is associated with floating which we don't have evidence for so now that I've probably ruffled your feathers a little bit and challenged some of your ideas about Theta and floating I want to give you an outline of what you can expect to get out of this talk okay so first we're going to have first we're going to talk about what happens to the brain during floating so we're going to look at actual EG activity recorded in the float tank and then we're going to test this Theta hypothesis we're going to see if Theta activity is actually enhanced by floating and then finally we're going to look at whether brain activity recorded in the tank predicts the subjective effects of floating so at this point I should introduce myself most of you probably don't recognize me this is my first float conference so my name is Joel frolick I'm an academic neuroscientist at the University of tubingen in Germany and I received my PhD in Neuroscience from UCLA in 2018. so shortly after getting my PhD I did a postdoc in the Monty Lab at UCLA studying Consciousness so specifically disorders of Consciousness and sleep but I also developed this side interest in Altered States Of Consciousness which is how I got interested in floating and I'm no longer in La I'm now a postdoc at The Institute for neuromodulation and neurotechnology at tubing in but I am still a consultant for the institute for advanced Consciousness studies in Santa Monica and let me tell you those folks are definitely interested in floating so I'm relatively new to the world of floating compared to most of you I had my first float experience in March 2020 and this was less than two weeks before a California issued its first stay-at-home order so really just on the eve of the covid-19 pandemic and lockdowns so my first experience was a two-hour float at float lab in Westwood Los Angeles so shout out to crash at float lab if he's listening to this and as I say this was a two-hour experience and it was my first flow so I had some doubt that I would make it through the whole session but sure enough the time just flew by and as soon as I got out of the tank I recognized what a powerful experience this had been for me and how it had reduced my own anxiety induced states of mindfulness and meditation now if you'd like to hear more about my first person experiences with floating I've written this article online titled my Out of Body Experience that's a nautilus magazine so you can check that out if you're interested getting back to the story so as I say this happened right at the beginning of the covid-19 lockdowns so I had many months of staying at home where I couldn't go float again but I could reflect back on this experience I'd had and I could ask myself how I could use my skills as a neuroscientist to better understand floating so naturally one of the first things I did was I looked up scientific papers on floating and I found the work of Justin Feinstein so many of you know Justin many of you know that he's a very friendly guy so I emailed him I started collaborating with him over Zoom and last year he shared with me these Bluetooth EG data recorded in the tank that I'll be presenting to you today so just to dive into some details of this experiment this happened at Liber in Tulsa Oklahoma and there were two groups of participants recruited so there were healthy control volunteers and there were also volunteers with clinical anxiety and the volunteers completed two experimental conditions so there's a float condition okay and the float condition is interroceptive now you may know that library has this open fiberglass float pool with no enclosure which is really great for participants of clinical anxiety okay it cuts down on the risk of claustrophobia and there's also work coming out of Library several years ago showing that floating is an interoceptive state so it enhances internal bodily Sensations such as breathing and this was compared to an exteroceptive film condition in which participants watched this BBC planet Earth nature documentary so naturally if you're watching a film your attention is directed outward yeah so it's an exteroceptive condition so to go into some technical details this was a randomized controlled trial meaning that participants completed both conditions but in randomized order and we collected EEG data in both conditions and in fact during the float we had usable EEG data from 36 subjects including 21 subjects with anxiety disorders and 15 non-anxious volunteers so I'll give you a breakdown of what these sessions looked like so they're both 90 minutes to float in the film and in the float we have 10 minutes at the beginning where there's lights and music that gently Fade Out to ease a participant into this stimulus-free environment yeah so that's at the beginning and then at the end of the float we have 10 minutes of lights and music that gently fade back in to ease a participant into a normal sensory environment so it's these middle 70 minutes here that are dark and silent and so that's where we chose to analyze the EEG data from now for those of you who have floated you know there's three stages roughly speaking to this experience there's this pre-float Baseline where you feel relatively normal presumably then you have what happens during the float itself which if you have a good session includes some interesting psychological effects and then you have this uh whoops then you have this post float Afterglow if my slides will go back to it where you have these after effects of floating okay and the after effects of floating have been studied already by Justin's team at Liber using fmri neural Imaging but what's really difficult is to study what happens during the float itself okay so to illustrate how this is non-trivial I want to use a more intuitive example so you might ask yourself if you've ever wondered whether the lights in your refrigerator stays on when the door is closed how would you ever know you could open the door and look inside but then you're ruining the very closed environment that you're trying to study so with floating we Face a similar challenge we can look inside the tank open it up put some instruments inside but then we're probably going to ruin the very stimulus-free environment that we want to study so I want to talk now about two common Technologies for studying brain activity in the laboratory one is fmri or functional magnetic resonance imaging okay this is commonly known as brain scanning so fmri has very good spatial resolution and it produces these pretty pictures of the brain that you see online and in the news and it looks it looks at what parts of the brain are using the most oxygen okay but unfortunately fmri has poor time resolution it's rather like watching a movie that's just one frame per second and we cannot use it to study these neural oscillations such as Theta which are four to eight cycles per second and furthermore if you've seen an MRI machine you know that it's this enormous magnets that weighs as much as an elephant right and the local magnetic field produced by the MRI machine is so powerful that it has to be kept in a specially shielded room away from metallic objects so obviously we're not going to deploy MRI in the float tank okay we can have subjects get out of the float tank and then go into the MRI scanner okay that's a study that Justin's team at library has done before but we cannot use MRI to study what's happening during the float itself so an alternative technology is EEG or electroencephalography so EEG is lightweight it's portable and it's inexpensive okay and it has low spatial resolution meaning it doesn't produce these pretty pictures of the brain but it has very high time resolution meaning we can precisely look at the timing of neural events and we can study neural oscillations such as Theta okay so far so good but there are a couple challenges to deploying AG in a float tank so one is tactile sensation here you can see this picture of me um wearing an EEG cap and this cap holds the electrodes together that oppressed against the scalp to record electrical brain activity and you know it's quite tight there's usually a chin strap that holds this in place and furthermore there's this conductive gel that has to be pipetted underneath each electrode and all of this creates a lot of tactile sensation okay which kind of defeats the whole point of going in a float tank in the first place so the next challenge is called bridging all of you know that the water and the tank is highly sailing and these salts can act as an electrolytes okay so they can carry current between electrodes and so if we have EG submerged underwater in the tank these electrodes are going to become electrically coupled okay so this means they're all picking up the same signal it would be rather like you're watching TV you're flipping through the channels and every channel is showing the same TV program okay so obviously that's not a desirable thing now fortunately the company neuroverse has come up with a very elegant solution to this problem in the form of a product called the brain station which you see right here oh whoops yeah right here so you may know neuro verse from Ricardo the CEO who's spoke in a previous float conferences and the neural verse product brain station it's attached to the forehead it stays above the level of the water and it's completely wireless okay it uses Bluetooth technology to record EEG signals so the brain station solves the problems that I've outlined already okay so there's minimal tactile sensation there's no cap okay nothing like that it's just this little device that fits on the forehead and Records frontal EG there's nothing submerged under water we don't have to worry about bridging and it's only one channel nonetheless it's designed to be waterproof and it's designed to be saltproof so it's wrapped in Tegaderm to protect it from Salt and it's wireless so this is Bluetooth technology there's no wires and there's no cables all right so now that I've told you how we can use EG to record signals in the float tank I just want to give you a brief primer on how to think about EEG like a neuroscientist so you probably already know I'm just going to make this more intuitive you already know that you can take white light send it through a prism and you get these different colors or frequencies of visible light out the other side and in the same manner we can take the EG signal send it through this mathematical tool called the Fourier transform and we get these different EG frequencies out the other side so I'm just going to go through the different EEG frequencies the lowest frequency that's commonly studied is called Delta okay so this is one to four cycles per second and it's often associated with states of deep unconsciousness like dreamless sleep and general anesthesia there are some big exceptions to this which will become important later in the talk so I want everybody to understand that no one frequency band is associated with just one function okay that's important next there's data which we've already talked about but just to recap it's four to eight cycles per second and it's often associated with states of interdirected attention such as meditation after Theta comes Alpha at 8 to 13 cycles per second Alphas associated with neural inhibition so for instance if you close your eyes the visual parts of the brain become inhibited and you see these very high amplitude Alpha Waves over visual cortex after Alpha comes beta beta is 13 to 30 cycles per second it's involved in various functions but most prominently bodily movements in the motor system and then finally we have gamma which has 30 cycles per second and upward so gamma is involved in cognitive functions like attention and working memory but it also overlaps with the frequency range of muscle activity and a lot of times EG is also picking up muscle activity in addition to brain activity which means that in EG studies we need to be careful to see that the gamma activity is really coming from the brain okay so I know I think you have a lot of information about neural oscillations but I still want to give you one more primer on how to understand the EG figures that I'll be showing you today so these are called time frequency representations and they're tools that show the EEG power at different points in time and in frequency so they look like this okay rectangular plot and on the horizontal axis of this plot we have time in minutes yeah and then on the vertical axis we have frequency and cycles per second or Hertz and notice that when we go up in frequency we go up logarithmically which means rather than counting linearly one two three four five we count logarithmically one two four eight sixteen thirty two and the reason we do that is because it results in more even spacing between the different EG frequency bands now finally there's this color bar here which shows the strength of the EG signal at different points in time and frequency and this is often set up as a contrast between two conditions so in this example we have a contrast between float and film it's float minus film and so where we see warm colors here like these Reds oranges and yellows yeah this is where we have more EEG power in the first condition the float condition where we have these cool colors these blues and cyans this means that we have less EEG power in the first condition the float condition and where you see green you have approximately the same power between these two conditions okay so just to recap I've overlaid the different EG frequency bands on top of this time frequency representation so we have the lowest frequency Delta down here and we have the highest frequency gamma up here and because we have this on a logarithmic scale frequency is logarithmic here we have roughly even spacing between the different EEG frequency bands so now if I take this overlap away what we're looking at right now is the contrast between the float condition and the film condition and the healthy participants in the study so I know this is a rather technical figure which is study it carefully see what patterns you can glean from it I think the first thing you'll probably notice is that there's a lot of warm colors here toward the bottom of the figure and remember when we're looking at the bottom of the figure we're looking at these low frequencies okay so that means that floating enhances low frequency EEG activity compared to the film condition and then if we look at the top of this figure we see that there's a lot of these cool colors these blues and cyanes and that means that in the high frequencies like gamma and beta we see attenuation of EEG activity in the float condition compared to the film condition yeah and you might ask yourself what frequency you think this enhancement is happening in at the bottom okay and you might be thinking about Theta but if you look at the vertical axis you can see a lot of these warm colors are between two or one in four Hertz okay and if you recall that's actually in the Delta band not the Theta band but the Delta bands so now what I'd like to show you is the contrast the same contrast between float and film but in the participants with clinical anxiety and I think you're going to see the same pattern even more clearly so again these are really technical figures so I'm just I'm going to give you a moment I'm not going to talk just really study this figure try to see what patterns you can glean from it and take a moment to digest it okay so I'm sure all of you probably see that there's a sea of red at the bottom of the figure right so even more clearly than in the healthy participants you see that there's this low frequency enhancement of EEG activity in the float condition compared to the film condition so the same pattern as we saw before but even more clearly and just like what we saw in the healthy participants there's this high frequency attenuation in the float condition compared to the film condition now let's go back to this low frequency enhancement again what frequency do you think this is happening in I'm sure a lot of you are coming at this with a Theta hypothesis so you might be guessing this is happening in Theta but if I overlap the Theta band on top of this time frequency representation you see that Theta actually misses almost all of this red okay it's missing most of this low frequency enhancement so remember everything below Theta is in Delta so what we're actually seeing is Delta enhancement with floating in these participants with clinical anxiety now as scientists we like to do statistical analyzes to see that our results are unlikely to be random occurrences due to chance yeah this can get rather technical but I'm going to spare you the nitty-gritty details and what you need to know right now is this is a Time frequency representation where we now have red outlines these red Contours surrounding clusters where you see significantly more power in the film condition compared to the float condition and both groups of participants so if you take a look you can see that these are rather broad clusters both in time and in frequency so they span almost the entire duration of the session and if we look at the frequencies they Encompass there's gamma beta so these high frequency these high frequencies that we would expect to see but then you also see a little bit of alpha and you even see a little bit of theta remember these are the frequencies that are being enhanced by the film condition not the float condition and now if we look at the Clusters that are significantly enhanced by floating relative to film we're not concentrating on again these red Contours here this is at the bottom of the figure okay so there's several of these clusters and they're quite low frequency and again you might ask yourself what frequency you think this is taking place in and I'm sure many of you still want to think that this is happening in Theta but if I put the Theta band on top of this figure you see that it misses almost all of this activity okay so these clusters are almost entirely beneath the Theta band so this is almost entirely taking place in the Delta band where we have significantly more EG activity during the float as compared to the film okay another thing we can look at is something called Group by condition interaction which is simply to say that we see slightly different effects of floating in one group versus another and you can see this visually for yourself I have the healthy plot on top of the anxiety plot so in the participants in the control condition you see that there's a little bit less of this low frequency enhancement than what you see in the participants of clinical anxiety you can just tell that qualitatively from your eye but where this really gets interesting is when we look at frequencies where there's significance attenuation of EG activity in the anxiety group okay so that's these new clusters you're looking at here surrounded in red you can see that there's a cluster at the beginning of the float okay which encompasses some high frequencies and some lower frequencies and then about 50 minutes in you have a couple more clusters and these clusters seem to be centered on the alpha band okay but you also have a little bit of the Theta band here and remember we're looking at the frequencies that are attenuated by floating not enhanced by floating but attenuated so you're actually seeing that floating doesn't enhance Theta activity if anything it's attenuating it so I'm sure at this point many of you are a little bit confused you're scratching your heads and you're asking what's going on and you might be saying how is it then EG marker interdirected attention and meditation is actually being attenuated rather than enhanced by floating well the first thing I would say in response to this is that meditation and floating are not necessarily the same thing many of us choose to practice meditation in the float tank myself included but floating is a broader activity nonetheless let's talk about meditation for a moment so there was this great review of the literature in 2015 by Lomas and colleagues and they looked at different studies that examined EEG Theta power in meditation and as you can imagine they found quite a few studies it was 10 or 11 studies that reported increases in Theta power during meditation okay however they also found a handful of studies that reported no difference between Theta and a resting condition or between meditation and resting condition with regard to Theta power okay and even more surprisingly you even find a few studies that report decreases in Theta during meditation so what's going on here well there's a lot of heterogeneity that needs to be understood so for one thing it matters quite a bit whether we're looking at participants who are novice meditators complete beginners right or if we're looking at experienced Buddhist monks and we should expect those two groups to have different neural signatures matters quite a bit what meditation tradition we're studying so as I'm sure you know there are many different styles of meditation and it might make a difference whether we're looking at vipassana or meta okay so if I can now take your attention away from Theta and back to Delta I told you at the beginning of this presentation that we would see whether EG activity recorded in the float tank predicts the subjective effects of floating and that's what we're going to see here in this figure so on the horizontal axis we have Delta power okay and on the vertical axis we have the change in anxiety so the change in anxiety was measured using the Spielberger State anxiety inventory which by the way was the primary outcome measure of the study when it was pre-registered on clinicaltrials.gov and just to help you understand this vertical axis so when you see Zero here this is no change in anxiety that means the participants felt the same getting out of the tank as they did going in no change in anxiety between 0 and 10 this red area we have increases in anxiety that means these participants felt worse getting out of the tank than they did going in between 0 and negative 40 we have decreases in anxiety and that means the participants felt better coming out of the tank than they did going in well the first thing I'd like you to notice is that all of these magenta points are participants with clinical anxiety okay and if you look at these they all had decreases in anxiety okay none of them felt worse getting out of the tank than they did going in they all felt better the next thing I'd like you to notice is that if we look at the correlation between Delta power and the change in anxiety it's a negative correlation so what that means is the more Delta power you had during your float the bigger a decrease in anxiety you experienced now I would want to see this replicated in a larger sample before I really commit to saying that yes the Delta power definitely predicts the change in anxiety but this is still important because it suggests that the Delta power rather than just being incidental to the effects of floating it may really be something that's involved in the anxiolytic effect so for the nerds in the audience this was a Pearson correlation of negative 0.3 and just to show you that this is specific to floating we can look at the same relationship Delta power versus anxiety change in the film condition and there's no significant correlation okay so this is really something that's specific to floating all right I know I've hit you with a lot of information and this is probably a little bit disorienting understandably so so I want to just pause for a moment and emphasize a few take-home points so first of all I hope it's obvious now but floating induces Delta activity not Theta activity but Delta activity and there's actually no reliable evidence to call floating a Theta state so I think for this reason we should stop calling floating a Theta state and furthermore I think we might want to start thinking about floating as a unique State of Consciousness and not necessarily put it in the same box as meditation now I'm sure many of you are probably still a little bit hung up on this Delta finding and you might be thinking to yourself wait wait a minute Delta isn't this just about states of unconsciousness and dreamless sleep well no it is true that you see Delta activity during unconsciousness but there are many exceptions to this which I mentioned earlier in the talk so before I had any interest in floating I actually did this research looking at Delta activity during conscious States and a couple colleagues and a couple colleagues and I at UCLA we did a review of the literature and we published this review in the journal brain it's called Consciousness among delta waves a paradox it's behind a paywall but I'm happy to email it to anyone who's interested and we found many different published studies that report EG Delta activity during wakeful consciousness and you might be very interested to know that one condition in which we observed EG or in which the literature reported EEG Delta activity during Consciousness is the psychedelic drug dimethyltryptamine or DMT so now that we have Joe Rogan's attention again let's talk about DMT for a moment so DMT is a psychedelic like LSD and psilocybin and induces this Rich visual experience along with perceived encounters with other entities but unlike some psychedelics when DMT is smoked it induces this sensory disconnect between the mind and the environment so this is a Dutch woman who just smoked a DMT on YouTube and you can see three and a half minutes after smoking DMT it looks like she's sleeping but she's actually not so she's having this very rich internal visual experience and there's some very interesting work coming out of Imperial College London by Chris Timmerman and colleagues showing that when you give DMT to Volunteers in the lab they have this increase in EG Delta activity and furthermore the strength of this Delta activity positively correlates with the intensity of the DMT trip now the difference between this Delta activity that you see in DMT and the Delta activity that you see during states of deep sleep is on DMT you see this Delta activity that's low amplitude so we would say it's less than 100 microvolts and during deep sleep you see this Delta activity that's high amplitude Okay it's often called slow waves more than 100 micro volts in amplitude now as it so happens there's a sensory disconnect between the mind and the environment that all of us experience every night okay it's called REM sleep or rapid eye movement sleep okay this is the stage of sleep where you're the most likely to be dreaming now I've already told you that we see Delta wave activity during non-rem sleep when we're not dreaming but it turns out we also can see delta waves in REM sleep this was not appreciated until recently but in 2019 there was a study by bernardian colleagues in the Journal of Neuroscience and they described delta waves during REM sleep and again this is a lower amplitude Delta wave than what you see in non-rem sleep or dreamless sleep okay so in REM sleep this is again less than 100 microvolts and what I think might be going on here is that this low amplitude Delta activity is a neural signature of an altered state of consciousness in which there's a sensory disconnect between the mind and the environment and of course when we go in a float tank we also have a sensory disconnect between the mind and the environment that's the very point of going in a float tank and we also sometimes have this internally generated imagery which I'll talk about in a few slides okay so I think this might be an explanation for what's happening in the float tank yeah with regard to Delta activity nonetheless a hard skeptic could still look at these data and say how do we know these participants weren't just sleeping couldn't it be that everybody was taking a nap and this is a question that I want to take very seriously okay it's a reasonable question especially because from my own experience you know I can often be in the tank and feel like I'm in this very ambiguous State of Consciousness I'm neither completely awake nor completely asleep so the study dealt with this in a few different ways so for one all the participants were explicitly instructed not to sleep but of course that doesn't mean that they didn't so they were then asked afterwards to estimate the proportion of the float that they spent sleeping and the average response was that they slept for 24 of the session so on average they're awake three quarters of the float and they're sleeping one quarter of the float but the good news is the good news is that the EG Delta activity does not correlate with the estimated sleep duration okay so you can see this here Delta activity on the horizontal axis and then estimated sleep duration on the vertical axis there's no significant correlation and in fact if we try to fit a line through these points if anything we see a negative slope the more Delta power you have the less sleep you have but it's not a significant correlation for the nerds in the audience this is a Pearson correlation of negative 0.1 another point which I think is relevant is that these same participants with anxiety disorders and a previous study of floating they are interviewed afterwards about their experiences in the tank and many of them had conscious experiences of light in the tank which we know is completely dark okay so one person said I saw little flashes of light like Starbursts randomly in different places it was beautiful okay so this person is having a visual experience that they were calling in the tank and while I'm not suggesting that this is dreaming in the conventional sense of the word it is possible that some of these participants are being pushed to this Razor's Edge between wakefulness and sleep known as hypnagogia which is often characterized by these sorts of mild hallucinations so a future direction for further studies would be to actually investigate whether floating induces hypnagogia okay I know it's been a long talk I've hit you with a lot of information probably some of it is disorienting and I think at the beginning of this talk we started with a very opaque and blurry image of what's actually happening in the tank and I'm hoping that in the course of this talk I've really clarified what's happening in the tank with respect to EEG signals but there are a couple more technologies that I would still like to see deployed in the tank one is called fnirs or functional near infrared spectroscopy so F news is looking at Optical absorption of infrared light by the brain and I'm optimistic that we might be able to deploy this one day in the float tank another technology is called opms or optically pumped magnetometers so these are extremely sensitive magnetic instruments that can detect very very weak biomagnetic fields and in theory we could put them in the bottom of the float tank maybe a couple centimeters beneath a person's head and we could actually use them to record neural activity and this would be the best case scenario because there would be nothing touching the person's body as we're recording this neural activity and then finally I think we should also use EEG to study the after effects of floating so remember there's this three three stages of floating right we just looked at what happens during the float and Justin's team has used fmri to look at the after effects but I would also like to use EG to look at these after effects of floating okay so long talk a lot of information here I know many of you are probably feeling a bit disoriented and questioning what you thought you knew about floating and Theta but I just want to emphasize some conclusions here so first of all I think I've made this clear but floating is actually not about Theta okay it induces Delta activity but there's no evidence that induces data activity Now Delta might relate to the anxiolysis that we see with floating okay we saw this with this correlation between EG Delta power and the change in anxiety but there's no evidence right now linking it to sleep okay we do not see a correlation between Delta power and estimated sleep duration so I've said this before and I'll say it again I think we should stop talking about floating as a Theta State because we don't see evidence for it right and I think we might want to think about floating really as a unique State of Consciousness we don't need to put it in the same box as meditation and we don't need to put it in the same box as sleep and finally by the way if I ask artificial intelligence to draw the float state of consciousness it also looks beautiful thank you very much [Applause] [Music]