Why Psilocybin (Magic Mushrooms) Causes Visual Hallucinations | Dr. Andrew Huberman
00:00:00.000 | [silence]
00:00:02.560 | The serotonin 2A receptors are located
00:00:04.680 | in multiple brain regions,
00:00:07.320 | but they have a tremendous amount of expression
00:00:10.480 | in the so-called neocortex,
00:00:12.000 | the outside of the brain that includes things
00:00:14.360 | like our prefrontal cortex,
00:00:15.520 | which is involved in understanding context, right?
00:00:18.280 | Which behaviors, thoughts, and speech patterns
00:00:21.440 | are appropriate for certain circumstances,
00:00:24.920 | how to switch context and category switch
00:00:27.680 | when you go from, you know, playing sports
00:00:29.040 | to hang out with friends to being in a professional setting,
00:00:30.840 | you change your behavior and the way that you speak
00:00:32.840 | and perhaps even the way that you think.
00:00:34.400 | You might think some things that are out of context,
00:00:36.640 | but you probably keep those to yourself,
00:00:38.280 | and your ability to keep those to yourself
00:00:40.000 | are dependent on a functional prefrontal cortex.
00:00:42.560 | There are a lot of 5HT2A,
00:00:44.800 | and by the way, 5HT is the abbreviation for serotonin,
00:00:47.440 | so there are a lot of serotonin 2A receptors
00:00:49.360 | in the prefrontal cortex.
00:00:50.720 | Also in other areas of the cortex
00:00:52.960 | that are associated with sensation and perception,
00:00:57.120 | that is hearing of sounds,
00:00:59.120 | that is seeing of particular things,
00:01:00.960 | and in particular, there is a very, very, very high expression
00:01:05.960 | of serotonin 2A receptors in the visual cortex.
00:01:10.720 | And that is one of the reasons
00:01:12.240 | why psilocybin triggers visual hallucinations.
00:01:16.320 | And provided psilocybin is present
00:01:18.360 | at sufficient enough concentration,
00:01:20.560 | that is taken at a sufficient dosage,
00:01:24.440 | one will experience profound visual hallucinations
00:01:27.320 | regardless of whether or not their eyes are open
00:01:30.440 | or their eyes are closed.
00:01:32.520 | Now, that's an important fact
00:01:33.680 | because it explains one of the major effects of psilocybin
00:01:36.240 | that people experience while they are on the drug.
00:01:39.720 | Now, as I'll talk about a little bit later
00:01:41.180 | in terms of what constitutes a useful psilocybin session,
00:01:45.320 | useful meaning that it's leading
00:01:47.160 | to adaptive improvements in mood,
00:01:49.680 | adaptive improvements in creativity and cognition, et cetera,
00:01:53.480 | is that people not have their eyes open
00:01:57.520 | for at least the majority of the psilocybin session.
00:02:02.120 | This is something I've discussed with several experts
00:02:04.760 | who are running clinical studies
00:02:06.180 | on psilocybin in their laboratories,
00:02:07.860 | some of whom are going to be guests
00:02:09.040 | on the "Huberman Lab" podcast in upcoming episodes.
00:02:11.960 | Again, I can't underscore this enough.
00:02:14.160 | Because your visual cortex contains so many
00:02:16.820 | of these serotonin 2A receptors,
00:02:18.760 | and because psilocybin binds so strongly
00:02:22.200 | to that serotonin 2A receptor,
00:02:24.680 | you're going to experience a lot of visual hallucinations
00:02:28.160 | when you are under the influence of psilocybin.
00:02:30.120 | There's no surprise there.
00:02:31.120 | This has been known for hundreds, if not thousands of years.
00:02:34.040 | It's one of the main reasons why people take psilocybin.
00:02:37.120 | However, as I mentioned earlier,
00:02:39.520 | these hallucinations occur even when the eyes are closed.
00:02:43.160 | And it's now fairly well-established
00:02:45.960 | that if people are to take psilocybin
00:02:49.040 | and have their eyes open, much of their cognition,
00:02:52.360 | much of their thinking, much of the time spent
00:02:54.800 | in that psilocybin journey is focused
00:02:57.800 | on the altered perceptions of things
00:03:00.400 | in the outside environment.
00:03:01.960 | Sometimes this looks like a sort of a fracturing
00:03:05.740 | of the outside world into kind of geometric shapes.
00:03:08.920 | Sometimes it appears as a kind of melting
00:03:12.080 | of things in the visual environment,
00:03:13.280 | including people's faces or a morphing of people's faces.
00:03:16.480 | All of that has a strong, let's just call it a draw
00:03:19.920 | for a lot of people who are looking
00:03:21.160 | for a highly unusual experience
00:03:23.120 | inside of the psilocybin journey.
00:03:26.160 | But I think if one's goal is to derive
00:03:30.320 | the long-lasting benefit from the psilocybin experience,
00:03:34.920 | it's very clear that having an eye mask
00:03:38.080 | or some other eye covering or something that ensures
00:03:40.360 | that one's eyes are closed for the majority,
00:03:43.600 | if not the entire psilocybin session,
00:03:46.480 | is going to be very useful because it's going
00:03:48.880 | to limit the extent to which one is focused
00:03:50.960 | on those outside changes in visual perception,
00:03:53.600 | aka hallucinations, and rather will allow the person
00:03:56.280 | to go inward to combine whatever it is
00:03:58.840 | that they happen to be seeing in their mind's eye
00:04:01.840 | with the different thoughts and memories
00:04:04.080 | and changes in their emotions that are occurring.
00:04:06.840 | And that going inward by staying in the eye mask,
00:04:10.520 | at least for the majority of the time,
00:04:11.960 | seems to be a very, if not the, critical feature
00:04:16.040 | of making the psilocybin journey effective
00:04:18.600 | in the therapeutic sense.
00:04:20.620 | (upbeat music)
00:04:23.200 | (upbeat music)
00:04:25.780 | [MUSIC PLAYING]