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Clinical Psychedelic Journey (Set & Setting) Explained | Dr. Andrew Huberman


Whisper Transcript | Transcript Only Page

00:00:00.000 | So let's talk about psilocybin journeys
00:00:04.320 | from the subjective side and from the structural side.
00:00:07.000 | And when I say the structural side,
00:00:08.680 | what I mean is what does a psychedelic journey
00:00:11.360 | actually include?
00:00:12.520 | And here are the words set and setting
00:00:15.160 | become extremely important.
00:00:16.480 | Some of you may have heard that set and setting
00:00:19.200 | are the foundation of a well done
00:00:23.520 | or even therapeutically beneficial psychedelic journey.
00:00:27.400 | And all of that really hinges on safety and outcomes.
00:00:30.560 | So set refers to mindset,
00:00:32.240 | the mindset of the person taking the psychedelic.
00:00:34.760 | And setting refers to, as the name suggests,
00:00:37.520 | the setting in which they're taking it in
00:00:38.880 | and the people that are present there.
00:00:40.860 | So let's talk about setting first.
00:00:42.760 | The setting for a psychedelic journey
00:00:44.800 | needs to be one in which the person
00:00:46.160 | under the influence of the psilocybin
00:00:47.760 | or other psychedelic is safe.
00:00:49.920 | That means no windows they can jump out of.
00:00:52.720 | That means no streets of moving cars they can run out into.
00:00:56.560 | That means no opportunity for getting lost.
00:00:59.240 | That means no opportunity for getting into bodies of water.
00:01:02.420 | In other words, it requires that there be at least one
00:01:06.200 | and perhaps even two or more other individuals
00:01:09.080 | who are not also taking psychedelics, right?
00:01:11.920 | Who are not also taking psychedelics
00:01:14.160 | present in that setting to ensure that the person
00:01:18.080 | taking the psilocybin is not going to harm themselves
00:01:20.780 | or others.
00:01:21.840 | I say this not to sound like a school teacher,
00:01:23.920 | even though technically I'm a school teacher,
00:01:26.640 | but because of course I don't want anyone to get harmed.
00:01:29.480 | And I'm also aware that there's a lot of interest nowadays
00:01:33.560 | in psychedelics such as psilocybin becoming legal
00:01:37.200 | or decriminalized for their therapeutic applications.
00:01:40.560 | And if we look back to the late 1960s and early 1970s,
00:01:44.160 | when the Controlled Substances Act was invoked
00:01:46.700 | to make psychedelics like psilocybin illegal,
00:01:49.640 | one of the bases for that
00:01:51.600 | was not just the geopolitical unrest at the time
00:01:54.880 | and things like the Vietnam War,
00:01:56.200 | but also some highlighted instances
00:01:59.260 | in which people did not take set and setting
00:02:02.260 | into consideration,
00:02:03.760 | took things like LSD, stared at the sun, went blind,
00:02:07.040 | or took psilocybin, went out and harmed somebody else.
00:02:10.880 | Again, these are very, very isolated instances,
00:02:13.760 | but these are the exact sort of instances
00:02:15.940 | that lead to criminalization
00:02:19.160 | or the fact that things like psilocybin and LSD
00:02:21.700 | and MDMA for that matter are considered illegal.
00:02:24.480 | Again, I completely acknowledge
00:02:26.160 | that there are a number of different factors
00:02:27.840 | making them illegal.
00:02:28.700 | We could have a whole discussion about that.
00:02:31.160 | We talk about the drug trade, the war on drugs,
00:02:33.220 | but right now is such a critical time in the history
00:02:37.300 | and the use of psychedelics for therapeutic
00:02:39.520 | and other reasons.
00:02:40.960 | And getting setting correct,
00:02:43.480 | meaning making it absolutely as safe as possible
00:02:46.080 | for the person taking the psychedelic is absolutely key.
00:02:48.560 | And one of the best ways to ensure that it's safe
00:02:51.360 | is to have responsible individuals
00:02:53.220 | who are not under the influence of psychedelics
00:02:55.160 | present in that environment.
00:02:56.640 | So that's one component of setting.
00:02:58.080 | The other component of setting that we talked about earlier,
00:03:00.480 | which turns out to be very important,
00:03:02.140 | is the opportunity and perhaps even the bias
00:03:05.680 | toward the person on the psychedelic being seated
00:03:08.880 | or ideally lying down and being in the eye mask,
00:03:11.400 | or at least having their eyes covered
00:03:13.240 | so that they can combine
00:03:14.720 | any spontaneous visual hallucinations that occur
00:03:17.840 | with the various thought processes that are occurring
00:03:20.320 | while under the influence of psychedelics.
00:03:23.020 | This is far in a way different than quote unquote,
00:03:25.760 | taking mushrooms and going into the woods
00:03:27.420 | or taking mushrooms and going to the beach.
00:03:29.680 | What we're talking about today is the use of psychedelics
00:03:32.640 | for particular brain rewiring outcomes that yes,
00:03:36.120 | can involve things like changing one's relationship
00:03:38.980 | to nature or changing one's relationship to somebody else
00:03:42.100 | by interacting with nature or somebody else.
00:03:44.040 | And while I'm not trying to diminish the potential value
00:03:46.960 | of those sorts of psychedelic journeys,
00:03:49.040 | if we look at the scientific data,
00:03:50.860 | the vast majority of it, not just in the clinical setting,
00:03:54.680 | but in terms of understanding the safety and efficacy
00:03:57.560 | and positive rewiring of brain circuitry
00:04:00.520 | that allows people to feel better,
00:04:02.020 | to understand themselves better,
00:04:03.400 | and to interact with life in more adaptive ways
00:04:06.160 | going forward out of the psychedelic journey,
00:04:08.400 | involve these very, let's say, subdued settings
00:04:14.080 | that are typically in one room, a closed environment
00:04:18.160 | with one or two other individuals acting as sort of guides
00:04:21.320 | or helping the individual by talking to them
00:04:24.880 | from time to time if they feel like they have to sort
00:04:27.020 | through a particular aspect of the psychedelic journey
00:04:29.460 | that's creating anxiety.
00:04:30.560 | And we'll talk about the contour of the psychedelic journey
00:04:32.640 | that almost everyone who takes psilocybin
00:04:35.080 | at somewhere between 20 and 30 milligram dosages
00:04:38.260 | tends to experience.
00:04:39.600 | But the setting that I'm describing is not just a list
00:04:43.040 | of things to make sure you're safe,
00:04:44.720 | but they're really the list of things that also ensure
00:04:47.480 | that one can get the maximum benefit
00:04:49.760 | out of the psilocybin journey.
00:04:51.720 | Now, other things included in setting that are known,
00:04:54.520 | again, from scientific literature, to be very influential
00:04:57.520 | in terms of the experience that one has
00:04:59.520 | and to bias things towards a positive experience
00:05:01.920 | are, again, safety, eye mask,
00:05:04.920 | but also the presence of music.
00:05:07.540 | Now, when I first heard about this
00:05:09.040 | from one of the premier researchers on psilocybin
00:05:12.280 | and other psychedelics, which is Robin Cardart-Harris,
00:05:14.360 | he's a professor at University of California, San Francisco,
00:05:17.440 | who's one of the major pioneers
00:05:19.240 | in the studies of psychedelics.
00:05:20.760 | And when he first started telling me about the critical role
00:05:22.820 | that music plays, I thought, okay, that makes sense.
00:05:26.160 | Music can impact our emotion, impact the way that we think,
00:05:31.160 | and could therefore impact what one experiences
00:05:34.720 | during the psychedelic journey.
00:05:36.000 | But he really underscored for me the extent
00:05:38.480 | to which music is not just a sort of incidental feature
00:05:42.940 | of the setting, in psychedelic setting,
00:05:46.060 | but that it is one of the major drivers
00:05:50.520 | of the actual cognitive and emotional experience
00:05:53.880 | that somebody has on something like psilocybin
00:05:57.740 | that allows the psilocybin journey to be looked at
00:06:00.560 | or viewed, not just as beneficial, but,
00:06:02.880 | and this is quoted in the scientific literature,
00:06:04.800 | as one of the most profound
00:06:06.360 | and important positive experiences
00:06:08.840 | that one ever experienced in their life.
00:06:11.400 | So let's talk about the sorts of music
00:06:12.780 | that have been used in these clinical studies.
00:06:14.920 | Well, first of all, we need to think about
00:06:17.440 | how long the psilocybin journey itself is going to be.
00:06:20.840 | And the typical duration of the psilocybin journey
00:06:23.140 | is anywhere from four to six hours.
00:06:25.640 | It's going to depend somewhat on dose.
00:06:27.640 | It's going to depend somewhat on variability
00:06:31.020 | in people's liver metabolism.
00:06:33.980 | And it's also going to depend somewhat
00:06:36.040 | on how much food people have in their gut.
00:06:38.620 | In all the clinical studies that I read,
00:06:41.440 | it was advised that people not have any food in their gut
00:06:45.800 | at the time at which they ingest
00:06:47.700 | or are injected with the psilocybin.
00:06:50.000 | It's particularly true
00:06:50.840 | if people are going to be taking psilocybin mushrooms
00:06:53.000 | in order to get their psilocybin.
00:06:54.520 | And that has been done in a few studies.
00:06:56.840 | Most studies, however,
00:06:57.680 | use synthetic psilocybin taken orally.
00:07:00.400 | Again, that's converted to psilocin in the gut
00:07:02.640 | by the acidity of the gut.
00:07:03.920 | And the acidity of the gut is going to be impacted
00:07:06.280 | by the various foods that people eat.
00:07:07.640 | And so that's one of the major reasons
00:07:09.460 | why people are advised to not eat for at least four hours
00:07:13.040 | prior to the psilocybin journey.
00:07:15.160 | So here we've got this six-hour, what we're calling journey,
00:07:18.460 | 'cause that's what everyone calls it, or trip,
00:07:21.180 | that people start experiencing about 30 to 45 minutes
00:07:26.000 | after ingesting psilocybin or taking psilocybin.
00:07:29.780 | There's a peak component
00:07:31.560 | in which there's a maximal intensity of emotion,
00:07:34.980 | and often that's also associated with anxiety.
00:07:38.200 | And this is very important to understand.
00:07:40.360 | The anxiety component is part of what,
00:07:43.340 | in the therapeutic setting,
00:07:44.380 | they refer to as ego dissolution.
00:07:46.600 | And that anxiety around the peak,
00:07:49.360 | and I think most people would probably hear peak experience
00:07:51.520 | and think, oh, we're talking about
00:07:52.840 | a peak positive experience.
00:07:55.240 | But no, we're referring to a peak experience in anxiety
00:08:00.400 | that people stay with and then come down from gradually
00:08:05.400 | as one goes from the second or third hour
00:08:08.440 | after taking psilocybin,
00:08:09.920 | and that tapers off slowly toward the six-hour mark,
00:08:14.480 | what sometimes people refer to as parachuting back in.
00:08:18.320 | Of course, they're not.
00:08:19.400 | Hopefully, I would very much hope
00:08:21.360 | people aren't actually parachuting back in
00:08:23.200 | while on psilocybin, but I think you get the idea.
00:08:27.180 | The music that's typically played in the clinical studies
00:08:30.940 | using psilocybin for the treatment of depression
00:08:33.420 | or for compulsive disorders or addiction
00:08:36.180 | tends to have a particular contour that matches with
00:08:39.740 | and can also drive that contour of the psilocybin journey
00:08:44.320 | that I just described.
00:08:45.700 | Again, we're talking about people wearing an eye mask
00:08:48.780 | with guides present,
00:08:50.240 | so people who are not taking psilocybin there as well
00:08:53.600 | to ensure that the person feels supported and is safe.
00:08:56.980 | The person is typically lying down,
00:08:59.540 | sometimes sitting down,
00:09:00.360 | but more often than not lying down, wearing an eye mask,
00:09:03.880 | and the music that's played
00:09:05.480 | at the beginning of the psilocybin session
00:09:08.100 | tends to be music that doesn't have a lot of vocalizations.
00:09:11.680 | It tends to be things like classical music.
00:09:13.580 | It tends to be fairly low volume,
00:09:15.660 | but that then transitions into music
00:09:18.860 | that has a lot of percussion, so often drums,
00:09:23.580 | that tends to be higher volume,
00:09:25.100 | that has a lot of intensity at about the time
00:09:29.100 | that one would be experiencing the peak in emotion
00:09:32.780 | and in perception, the so-called peak of the journey.
00:09:35.720 | That intense music tends to be played
00:09:39.060 | for about 45 minutes to 90 minutes,
00:09:42.440 | depending on the study one looks at,
00:09:44.580 | and then tends to transition into softer music again,
00:09:49.400 | sometimes choral type or more melodic music,
00:09:52.540 | often female voices in particular,
00:09:54.900 | and then transition into nature sounds
00:09:57.220 | and things that more or less mimic
00:09:58.620 | the outside natural world and less so synthetic things
00:10:03.340 | like drums or instruments and vocalizations
00:10:05.720 | and things of that sort.
00:10:06.860 | So why would it be so important that music match
00:10:10.020 | and even contribute to the subjective experience
00:10:12.820 | that people have on psychedelics?
00:10:14.260 | And here we should probably take a couple of moments
00:10:16.660 | and just talk about what those subjective experiences
00:10:19.220 | are like.
00:10:20.060 | So for people that haven't done psilocybin
00:10:21.540 | or any psychedelics, it's a little hard to describe,
00:10:25.160 | but one way to describe it is that there's a lot
00:10:27.940 | of so-called perceptual blending.
00:10:29.760 | So for instance, people in the eye mask
00:10:32.380 | will report seeing some geometric shapes and colors,
00:10:35.420 | but perhaps the music they're listening to
00:10:37.460 | will then start to change the intensity
00:10:40.400 | or the movement of whatever it is that they're seeing,
00:10:43.380 | hallucinating inside of the eye mask
00:10:45.580 | in ways that are linked.
00:10:46.740 | This is referred to as synesthesia
00:10:48.820 | or the merging of different senses
00:10:50.380 | that are not ordinarily merged.
00:10:52.840 | In addition, people under the influence of psilocybin
00:10:55.480 | or other psychedelics for that matter,
00:10:57.540 | often will report that their pattern of breathing
00:11:00.420 | becomes linked to the perceptions of things
00:11:03.620 | that they are hearing or seeing or feeling.
00:11:06.140 | So for instance, if they take a big deep breath in
00:11:08.660 | and then a long exhale out,
00:11:10.180 | they may find that during the long exhale out
00:11:12.900 | that the notes of music that they're hearing
00:11:14.940 | in those moments are also drawn out
00:11:17.800 | for the duration of the breath,
00:11:19.020 | and they'll inhale and that they're getting
00:11:20.820 | at least what they perceive as control over the music,
00:11:24.200 | which of course they are not actually controlling
00:11:26.140 | by using their breath.
00:11:27.660 | And that perhaps their visual perceptions
00:11:29.880 | are also being merged with that.
00:11:31.480 | So those are just a couple of examples
00:11:33.240 | of how perceptual blending, aka synesthesia,
00:11:36.500 | can occur while under the influence of psilocybin.
00:11:39.100 | And this really is highly individual
00:11:41.420 | from one person to the next.
00:11:42.840 | Some people, for instance, will find
00:11:44.520 | that if they take their fingertips
00:11:46.220 | and rub them across the couch or the chair
00:11:49.100 | that they happen to be lying down or sitting on,
00:11:51.300 | that they will experience a change in the music.
00:11:54.420 | Maybe even if they move their hand up,
00:11:56.580 | they hear an increase in frequency of sound,
00:11:58.280 | they move their hand down,
00:11:59.180 | they hear a decrease in frequency of sound,
00:12:00.740 | and that all of this is linked to their emotional state
00:12:03.740 | at the same time and vice versa.
00:12:05.460 | Okay, so we're talking about a lot of perceptual
00:12:08.220 | and emotional blending and some sense of control
00:12:12.460 | over one's perceptions and emotions
00:12:15.220 | in a way that's very unordinary, even extraordinary.
00:12:19.980 | Now, we can step back from all of this
00:12:22.140 | very subjective description of the psychedelic journey
00:12:24.660 | and ask what is going on
00:12:26.980 | that would allow these sorts of things to occur?
00:12:29.500 | And there you are already equipped
00:12:30.980 | with an understanding of the cell biology and the chemistry
00:12:33.360 | that makes all of this possible.
00:12:35.060 | And that is that when psilocybin is ingested
00:12:38.700 | and then converted to psilocin,
00:12:40.260 | and it's the psilocin that crosses the blood-brain barrier,
00:12:42.820 | and then even though psilocin looks a lot like serotonin,
00:12:45.940 | psilocin has this incredible ability
00:12:47.700 | to predominantly activate the serotonin 2A receptor.
00:12:51.580 | Well, we can understand much of what's happening
00:12:55.260 | at a subjective level during the psychedelic journey,
00:12:57.900 | even right down to the sorts of emotions
00:12:59.780 | and perceptual blending, the synesthesia.
00:13:02.100 | We can understand a lot of that
00:13:03.700 | by understanding where the serotonin 2A receptors
00:13:06.780 | are expressed on neurons
00:13:08.780 | and what those particular neurons are doing.
00:13:11.420 | And the simplest way to describe this
00:13:12.900 | is that there's a category of neurons
00:13:15.180 | that we call pyramidal neurons.
00:13:16.540 | Pyramidal neurons are found lots of places in the brain,
00:13:19.160 | but they're called pyramidal neurons
00:13:20.340 | 'cause they're shaped like a pyramid.
00:13:22.240 | They have a cell body, which is the part of the cell
00:13:24.140 | that has the DNA in it,
00:13:25.740 | and a lot of other important things
00:13:28.060 | like the organelles, mitochondria, et cetera.
00:13:30.920 | And then they also have what are called dendrites.
00:13:32.940 | Dendrites are the little branches or processes
00:13:36.100 | that reach out both from the bottom of these cells,
00:13:39.300 | and then these pyramidal cells are interesting
00:13:42.460 | because they also grow a branch up, up, up, up, up, up
00:13:45.740 | into layers of neural tissue above them,
00:13:49.060 | and they have what's called an apical branch.
00:13:50.780 | That's the part that grows up,
00:13:52.020 | and then they fan out at the top.
00:13:53.980 | And that fanning out at the top
00:13:55.380 | allows them to communicate
00:13:56.540 | with other neurons in their environment.
00:13:58.340 | Okay, so if you're not getting a good picture
00:13:59.780 | of this in your mind for my description, I apologize,
00:14:02.180 | but simply think about putting your arms out to the side,
00:14:06.620 | and by doing that, you're able to interact
00:14:08.580 | with things that are some distance from your body,
00:14:10.580 | sort of an obvious thing in that case.
00:14:13.160 | These cells are effectively doing the same thing
00:14:15.300 | by extending little processes out into layers above them
00:14:19.620 | and to the sides.
00:14:20.900 | And this is really important
00:14:22.020 | because much of the serotonin 2A receptors
00:14:24.660 | that are present on neurons in the brain
00:14:26.380 | are present in those apical dendrites,
00:14:28.820 | those branches of these pyramidal neurons
00:14:31.580 | that are above and that extend out
00:14:34.020 | to the side of those neurons.
00:14:36.020 | And so when somebody is under the influence of psilocybin,
00:14:39.500 | that means that psilocin has bound to the receptors
00:14:43.700 | on those apical dendrites,
00:14:45.260 | and it's increasing lateral communication
00:14:47.980 | across brain areas.
00:14:49.500 | In fact, this is perhaps one of the most
00:14:52.020 | well-documented effects of psilocybin and other psychedelics,
00:14:55.860 | which is that there's a shift
00:14:58.060 | from the brain being more modular, meaning more segmented,
00:15:01.140 | like auditory neurons are communicating electrically
00:15:03.860 | and chemically largely with other auditory neurons.
00:15:07.100 | Of course, they'll communicate
00:15:07.940 | with other types of neurons too, right?
00:15:09.340 | When I hear something off to my right,
00:15:10.860 | you know, like a snap of fingers off to the right,
00:15:12.700 | I'll turn my head and my ability to do that
00:15:15.540 | depends on my auditory neurons being linked up
00:15:17.580 | with things like my motor system and my visual system.
00:15:20.300 | But the key thing to understand is that
00:15:23.100 | when there is psilocybin present in one system,
00:15:26.660 | that the communication of any of these pyramidal neurons,
00:15:31.780 | the ones involved in hearing,
00:15:32.940 | the ones involved in thinking,
00:15:34.580 | the ones involved in memory,
00:15:36.180 | the ones involved in visual perception,
00:15:38.980 | or in the generation of visual hallucinations
00:15:41.220 | with eyes closed,
00:15:42.620 | those are all talking to many, many more other neurons
00:15:47.540 | more extensively.
00:15:49.420 | So what happens effectively
00:15:51.240 | is that there's a reduction in the modularity,
00:15:53.840 | the separateness of function in the brain,
00:15:56.180 | and an increase in what's called integration
00:15:59.760 | of communication across
00:16:01.840 | what would otherwise be disparate brain regions.
00:16:04.600 | We can say that really simply by saying
00:16:06.680 | psilocybin increases communication across the brain.
00:16:10.760 | Now, in addition to that,
00:16:12.360 | there's a reduction in what's called
00:16:13.920 | the hierarchical organization of the brain.
00:16:16.320 | Typically, sensory information comes in
00:16:18.800 | from the outside environment.
00:16:19.960 | So we hear something, we see something,
00:16:21.540 | we taste something, we smell something.
00:16:23.760 | And in what's called a bottom-up fashion,
00:16:26.700 | meaning bottom from the periphery,
00:16:29.480 | up, meaning it propagates up through the eyes,
00:16:32.920 | through the nose, through the ears, through the skin,
00:16:36.440 | or the senses in those regions, I should say,
00:16:38.880 | up into areas of the brain that sit deep to the cortex,
00:16:43.540 | like the thalamus.
00:16:44.640 | And then the thalamus is sort of a way station.
00:16:48.280 | It's like a switchboard
00:16:49.320 | that sends visual stuff to the visual centers,
00:16:51.120 | and auditory stuff to the auditory centers,
00:16:52.840 | and touch stuff to the touch centers,
00:16:54.240 | and things that maybe trigger a memory
00:16:57.280 | off to the memory centers of the brain, et cetera.
00:17:00.040 | That's the typical organization.
00:17:01.400 | It's hierarchical because it goes from the periphery up
00:17:04.280 | to the more complex processing regions of the brain
00:17:06.720 | that make decisions,
00:17:08.080 | that link all of that stuff to prior experience,
00:17:10.940 | maybe plans about the future.
00:17:12.900 | When psilocybin is present in the system,
00:17:16.160 | there's a broadening of the flow of that information
00:17:19.720 | from the bottom up as well.
00:17:22.120 | Okay, and that has to do with what's called thalamic gating.
00:17:24.520 | The thalamus is a very interesting structure.
00:17:26.320 | We probably don't want to go into it
00:17:27.360 | in too much detail right now,
00:17:29.220 | but it really is like a switchboard and a way station
00:17:31.720 | saying, hey, pay attention to the visual stuff.
00:17:34.520 | Pay attention to the auditory stuff,
00:17:35.840 | or just to the visual and auditory stuff,
00:17:37.440 | and ignore touch sensation for the time being,
00:17:40.480 | or vice versa.
00:17:41.400 | When psilocybin is present in the system,
00:17:44.840 | and when serotonin 2A receptors
00:17:46.960 | are activated very strongly,
00:17:48.940 | there's a tremendous broadening
00:17:51.380 | of the flow of information up and through the thalamus.
00:17:54.300 | So not only is there more communication
00:17:55.980 | of so-called higher order brain centers,
00:17:58.460 | we refer to them as higher order
00:17:59.780 | because they're involved in thinking and decision-making
00:18:01.700 | and emotion, et cetera,
00:18:03.020 | but there's also a shift in the flow of sensory information
00:18:07.020 | into the brain that can generally be described as broader
00:18:11.460 | and including more blending of the different senses.
00:18:15.020 | And when I say blending of the senses,
00:18:16.540 | I'm also referring to blending of the sense of interoception
00:18:20.200 | of our sense of our body
00:18:21.960 | and what's happening inside of our body.
00:18:23.900 | And this, without question,
00:18:26.460 | at least partially explains
00:18:28.300 | why when under the influence of psilocybin,
00:18:31.460 | one's breathing can be linked to a sound,
00:18:33.740 | and then suddenly the sound, one thinks,
00:18:36.900 | is being controlled by one's breathing,
00:18:38.940 | or that the sound itself can be linked
00:18:41.380 | to something that we see in our mind's eye
00:18:43.800 | while in the eye mask.
00:18:45.240 | Essentially what I'm describing here
00:18:46.620 | is that serotonin 2A receptor activation
00:18:50.220 | allows for more broad, less precise,
00:18:53.860 | and less hierarchical activation of brain circuitry.
00:18:57.100 | And when I say hierarchical,
00:18:58.780 | what I mean is that normally things go from periphery,
00:19:01.720 | from eyes to thalamus to visual cortex.
00:19:04.540 | However, when under the influence of psilocybin,
00:19:07.500 | as I mentioned before, even in the eye mask,
00:19:09.860 | the visual cortex is going to be very activated
00:19:11.940 | even in the absence of any visual input.
00:19:14.200 | So then if one hears a sound, perhaps from music,
00:19:19.020 | a particular motif or voice,
00:19:20.740 | and that's linked to a particular emotional state,
00:19:23.100 | that is now being blended with visual phenomenon
00:19:26.540 | occurring within the brain that have no external stimulus.
00:19:29.620 | And so while the patterns of activation in the brain
00:19:32.700 | while under the influence of psilocybin aren't random,
00:19:35.520 | they are far less channeled, far less modular,
00:19:38.740 | and far less hierarchical than would ever be the case
00:19:41.940 | when not under the influence of psilocybin.
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