Exploring Consciousness: Anil Seth on Reality, AI, Perception, and Psychedelics

Episode Transcript
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(00:00):
What is consciousness? How do we perceive reality? Will AI become conscious?
We discuss these questions and more with Dr.
Anil Seth, the author of Being You, A New Science of Consciousness,
and the author of a TED Talk with more than 14 million views.
Curiosities, this is a great conversation. I hope you enjoy it.

(00:22):
It. Dr. Seth, welcome to the show.
I saw your talk at the Royal Society recently online and you dedicated the presentation to your mother.
You said, when the end of consciousness comes, there is nothing to be afraid
of. And I was wondering if you could talk about that dedication for a moment.
Well, she's been in rather poor health for a long time.

(00:45):
And actually, it was a quite a surreal evening giving this seminar of the real
society for this the faraday prize it was this very prestigious lecture but
my mother had gone downhill health-wise,
over the last few days so she's recovered a bit now but at the time it wasn't
clear whether she was going to make it in fact we didn't think she was so it

(01:09):
reminded me of this and one of the
things I think about when I think about consciousness is the existential implications
and how we think about the beginning of life and the end of life.
And there's a Julian Barnes novel which has the title, Nothing to be Frightened of.
And it's all about mortality and our attitudes to mortality.

(01:30):
And so I basically, in my book too, I've used that phrase because I think it
has this beautiful double meaning that the absence of any kind of consciousness
can be simultaneously both terrifying,
we can be very frightened of nothing.
But of course, there's the other interpretation that if there's nothing,

(01:52):
well, you know, there's no pain, there's no suffering.
We don't worry too much about the vast expanse of time before we were each born.
Born so why should we worry too much about
the vast expanse of time after we die when
we won't be around to experience anything
it's a very very challenging

(02:14):
concept to keep in mind i mean people can spend their whole lives struggling
with the idea of not existing and it's something we mentally very hard if not
impossible to fully grasp because the act of grasping anything thinking anything
implies being aware, being conscious.
And the closest I think most people come to is something like general anesthesia,

(02:39):
where we are totally gone, we're not just asleep.
It's as close to the oblivion of death that I think for many of us we will ever encounter.
And so in your estimation, what is death?
Well, I think we need a little bit of humility here.
I can't be 100% sure what happens when we die.

(03:04):
No one lives to tell the tale.
But it seems likely, based on what we know about the brain and the brain's relationship
to having any kind of experience, is that when the brain stops, we stop.
Over history the notion of death has changed

(03:25):
quite a bit and there's but both in
how we think about it from our cultural traditions
of religion in terms of things like you know the afterlife and hell and heaven
or some or the bardo or other things but also medically you know the point of
death has changed from when somebody stops breathing to when their heart has

(03:48):
stopped to now Now, when their brain stops,
I mean, that's clinically when death is established.
But even that is now becoming a bit more of a gray area than it used to be.
When exactly do we say that the brain has stopped to a point that it cannot be resuscitated?
And advances in medicine are wonderful, but they tend to have this side effect

(04:10):
of complicating these clear lines that we might otherwise have drawn.
Well, let's start with the most basic question. What is consciousness?
It is a basic question. It's, of course, a very tricky question.
I mean, it's one of those words that I think we all used in different ways.
And we certainly encountered it's being used in different ways.

(04:31):
For some people, consciousness refers to something at the level of society.
Do we have a collective consciousness and awareness
of our impact on the rest of the
planet it as a human society i'm
not referring to that sense of consciousness
at least not in in the work that i do in my
lab and in my writing consciousness in

(04:54):
this sense has a very relatively precise
meaning it is what goes away under general anesthesia and as
we've just discussed at death too that's the ultimate loss
of consciousness the philosopher thomas nagel
puts it like this he says for a conscious organism there is
something it is like to be that organism it

(05:15):
feels like something to be me or to be you or to
be many other different kinds of animal probably
but for a table or a chair or a
laptop computer there's nothing it
is like to be that for the thing itself and they're
just complicated objects and i like this
definition because it's it's very liberal in the sense of it It avoids the tendencies

(05:41):
or what we might tend to do is associate consciousness with other things like
intelligence or language or explicit awareness of myself as an individual.
All of these things might be associated with human consciousness,
but consciousness itself I think is much more basic.
It's just any kind of experiencing at all, pain, pleasure, red,

(06:02):
green, any of these things.
Whenever there is experience, there is consciousness.
Now you talk about the brain as a prediction machine and that reality is a controlled
hallucination that stems from this prediction machine.
Can you tell us what you mean by that?
Two things. There are two separate claims there in a sense. This first idea

(06:26):
of the brain as a prediction machine is a hypothesis about a fundamental principle
of operation of the brain in the body that I think is very useful for understanding
how we work and how consciousness,
manifests in ours and in other systems too.
We'll explain a bit more about that in a second. The other thing you said though,

(06:47):
that reality is a controlled hallucination is not quite what I say.
And the distinction is important.
I think reality exists. It's real.
Reality is real. it doesn't depend on our minds however
the way in which we experience reality that
is a kind of construction that is what i think of as a controlled hallucination

(07:10):
so you know we never see things or hear things as they really are the way in
which we encounter objective reality is is always a kind of construction that
is very tightly geared to objective reality evolution is made very sure of that.
So there's no sort of slipping into nihilism or relativism or any of these things

(07:32):
or idealism when we say that reality doesn't exist.
Now, the way I understand all this is through this concept of the brain is a prediction machine.
And this can mean prediction of the present, not necessarily prediction of the future.
And the way to understand it, I think, is to imagine being a brain.
Imagine you are your brain, you're trapped inside the skull,
trying to figure out what's going on out there

(07:54):
in the world and from the brain's perspective
all it's got access to are these electrical signals maybe
a few chemicals swishing about things are very indirectly
related to how things are they didn't come with labels on these electrical signals
all these chemicals so from the perspective of the brain figuring out what's
going on has to be a process of inference of best guessing of the brain figuring

(08:20):
out what is the the most likely state of the world and the body,
given this barrage of unlabeled ambiguous signals,
and the brain's prior expectations or beliefs or models about the way the world and the body is.
And so the claim here is that the brain is always making predictions about what's

(08:44):
out there in the the world or in here in the body, and using sensory signals
to update these predictions.
So when we experience something, when we perceive something,
it's not really a readout of the sensory input, though that's the impression
you get on reading textbooks in neuroscience.
And maybe that's how things seem to us. It seems as though the world just pours itself into our minds.

(09:08):
But actually, it's the other way around. The brain is always making these predictions in an.
Inside-out or top-down direction that are
constantly being refined and calibrated by sensory
signals and my claim is what we
experience well that's the predict that's the
top down predictions we actively construct the

(09:29):
worlds that we experience we don't just passively register perception then the
brain's interpretation of reality as it exists that perception is the bridge
between reality and then the way we experience it would that be accurate yeah i think it's a very
good way of putting it i mean perception itself can

(09:51):
be divorced a little bit from this bigger challenge of
understanding consciousness and perception can be thought
of as how any system makes sense of sensory data to figure out some useful interpretation
of it so we can build artificial intelligence systems that could be said to
perceive their worlds because they're They're not just directly reflecting sensory inputs.

(10:15):
They're making some interpretation of it.
And then consciousness is this yet further aspect that for humans,
and I think probably not for machines, but for humans, sometimes this process
is accompanied by a conscious experience.
Our brains aren't just doing complicated information processing.

(10:35):
When we open our eyes and look around, we have a visual experience of the world or the body.
Or, you know, not just in a visual experience, an auditory experience,
an emotional experience.
So, yes, in this sense, the mechanisms of perception do indeed provide a bridge
from objectively what's going on in the world and the body and subjectively

(10:57):
what's happening in our experience of that.
That well along those lines you said color
is where the brain and the universe meet could
you expand on that idea a little bit i
think color is a good place to start to unpack some
of these ideas and colors are very very
important aspects of our lives i mean you're wearing this

(11:17):
vibrant red jacket at least it looked red on my screen
now uncharacteristically blue
sky outside my window in england but what
is color color's been debated in philosophy
and science for hundreds of years but and
there's still a lot of discussion but there are a few things we can say that

(11:38):
shed light on on these ideas of perception color is not really out there in
the world as color it's not that objects are literally blue or red they just
reflect electromagnetic radiation in different waves.
Now there's this whole spectrum of radiation going from radio waves with very
long wavelengths to x-rays and gamma rays with very short wavelengths.

(12:02):
None of these things are actually colored, it's just different wavelengths of energy.
And there's a very small part of that spectrum, the so-called visible spectrum,
which is a thin slice of this objective reality.
And then within that thin slice, the cells in our
eyes are sensitive to roughly only three different wavelengths we
call them red green and blue but they're not red green and blue
they're just three different energies out of

(12:26):
combinations of these wavelengths our
brain creates a universe of colors you know many more than three we experience
thousands perhaps hundreds of thousands perhaps millions of distinct colors
so color in our experience is simultaneously less than what's really there,

(12:47):
because it's based on a very tiny subset of this wide spectrum of electromagnetic radiation.
But it's also more than what's there, because we experience this vast repertoire of colors.
And it's a useful thing for the brain to kind of construct, because what colors
help us do is keep track of surfaces as lighting conditions change.

(13:11):
So there's a very useful way for the brain to kind of pass reality because it
just presents objects in visual experience.
We have experiences of objects with different colors.
They look different from each other and they have a continuity as the ambient light changes.
But without brains, there would not be colors.

(13:32):
So in this sense, color is different from many other things.
The philosopher John Locke talked about this a lot. Colors really do require
a brain to exist. Otherwise, there's just electromagnetic radiation.
But other things that we might experience, like how heavy something is or how
solid something is, I mean, those properties exist independently of a mind and a brain.

(13:56):
If I'm not looking at a wall and I walk into it, I'll still stop.
I'll still hit the wall and fall over. it doesn't just stop
being solid because my brain isn't perceiving it
but the experience of looking or touching a solid object now that is a construction
the way solid objects feel to us is a construction but yeah color now i think

(14:21):
i don't think it was my quote i think i probably like most things borrowed it
from somewhere else but the color being where the brain and the universe meet,
I think just emphasizes this kind of humbling perspective that such an important
part of our daily lives is this collaboration between the brain and the world.
It's not just to be taken for granted.

(14:43):
We actively generate it every moment of every day.
There was discussion of that in your book, Being You, The New Science of Consciousness,
which is an amazing book, by the way, highly recommend it to anyone listening to this conversation.
If you're interested in these topics, you talked about a walking meditation

(15:03):
in which you're trying to keep that front of mind, the relationship between brain and colors.
And I found that's a very useful way to.
Just be in awe of everything around us and how much is going on in terms of perception and color.

(15:23):
And I just wanted you to just touch on that a little bit about how you exercise
that walking meditation.
Cause I think that's a really useful exercise for anybody that's interested in consciousness.
I mean, anything but a diligent meditator, I've kind of dabbled in meditation,
but dabbling in meditation is not the generally, it's not generally the best way to, um,

(15:44):
to practice But I do think that years of studying and thinking about consciousness
is in a way a form of meditation.
And the two things meet a little bit more in this idea that you just mentioned.
And it's something I find myself doing without really thinking about it as meditative practice.

(16:04):
But quite frequently walking around or just sitting outside in nature or even
in the house and just reminding myself, and this becomes for me a bit of an
automatic mental habit,
that what I'm experiencing,
even though it seems to be objectively the way it is, and my brain is just open

(16:27):
to the world as it is, it's not true.
That the colors, the shapes, the sounds that I'm hearing, they are all constructions
of the brain that are reigned in by objective reality.
They're not literally out there.
And you're absolutely right that if you do this, and I find if you do this,

(16:49):
it stops you taking consciousness for granted.
And that, I think, can be very rewarding and rewarding.
To some extent empowering experience it
certainly imbues most of the
time for me a sense of wonder and a bit of a sense of gratitude for
for this process to exist

(17:10):
i mean perhaps being conscious of something
was evolutionarily optional maybe
other forms of life on other planets could have
evolved to behave and survive and reproduce without
consciousness being part of their story at all i
think it's unlikely but but who knows along those

(17:30):
lines of color you talk
about is it adleman adleman how do you pronounce the checkerboard oh oh no that's
adelson so there's there's very similar names my old boss was called gerald
adleman but there's a very well-known visual illusion called adelson's checkerboard
different people different things there we go No. Okay.

(17:53):
Adelson's checkerboard. What can we learn from Adelson's checkerboard?
I think it's like many visual illusions. You often first see these things and
they just give you this sense of, wow, that's weird.
I, you know, that's, that's not, that doesn't seem right.
What trick is my visual system or what trick is my brain playing on me?
But I think the real value of these things is that it's not a trick.

(18:15):
Your brain is not playing any kind of trick on you, visual illusions are windows
into how the brain works all of the time.
So just to describe for anyone listening what Adelson's checkerboard is,
it's an image that shows us how deeply our brain's predictions about the world

(18:37):
shape what we experience.
So basically, you see a checkerboard which has kind of light gray and dark gray
squares arranged as like a chessboard, you might see.
And there's a little column, a round cylindrical shape that's at one end of
the checkerboard casting a shadow and the shadow is falling over the checkerboards.

(19:00):
And what we seem to see is just this checkerboard with a shadow passing down
along the diagonal of the checkerboard.
But if we focus on the individual patches, then something strange is revealed,
which is that two squares on
the checkerboard you can find two that look very

(19:21):
different shades of gray like the one under shadow looks much
darker than the one not under shadow but if
you take all that context away and all you're
looking at are these two squares they turn out to
be exactly the same shade of gray exactly the same
it doesn't matter how often you do this it
just works it works as strongly as it

(19:42):
did i've seen this thousands of times and so
what's happening here it's very surprising because these squares
are so obviously the same shade and they look so obviously different when you've
got the context it's because context gives the brain an expectation about the
scene and what and perception what it's trying to do is not just just reflect

(20:03):
sensory signals directly like,
yes, this patch of our visual field has this much value on the grayscale.
It's trying to figure out what's going on. And the best explanation for what's
going on is that there is a checkerboard and checkerboards and checkerboards,
the colors alternate, but some of it's under shadow. So that's what we experience.

(20:26):
We don't experience the.
Context-free properties of light, then the key realization is,
well, this isn't just a weird quirk happening here.
This is happening all the time. All of our experiences, whether we realize that
they're constructions or not, they all are.
It just becomes obvious in certain situations.

(20:48):
Yeah, I think it's an interesting idea that all of our experiences influence
this prediction machine, well beyond vision.
The brain is making predictions about everything in our conscious experience all the time.
And that is going to influence everyone else differently in terms of their prediction machine,

(21:11):
so to speak, is wired specifically to them a little bit differently,
which is going to change how they perceive a conversation,
how they perceive words and ideas.
Ideas and it seems
useful in terms of a way to create a
little more empathy and understanding especially when

(21:31):
in when disagreeing with other people no i think you're yeah i very much agree
there are three ways to think about this idea of prediction machines very very
briefly worth distinguishing i mean one is very mechanistic it's a claim about
what the neural circuitry in our brains are actually doing,
actually throwing these predictions and updating them in a particular way.

(21:54):
That still stands as a hypothesis, right?
I mean, one of the things I'm trying to do in my lab and many other labs too,
is trying to nail down these details and figure out exactly what's going on.
Is it really true that the brain is doing this?
I think there's a lot of evidence for it, but it's still, you know,
it's still a hypothesis.

(22:14):
The second thing which becomes much clearer is
that whatever's going on under the hood there is
this deep effect of the brain's expectations
about what we experience the adelson's checkerboard many other examples it's
very very clear that what we experience is not a direct reflection of what's

(22:36):
there expectations context and so on deeply shape it however it's actually working under the hood,
and then the third thing is an implication which as you said and it's something
I've become very interested in lately is that.
Given that these expectations that the brain has that we might not even know

(22:57):
our brain has, because by the way, you don't need to know that your brain knows stuff about shadows.
It just does. And we don't need to know that our brain knows that.
Given that that is actually happening in some way, it's very likely happening
in slightly or even substantially different ways for different people.

(23:18):
And I like to think of this in terms of the concept of perceptual diversity,
neurodiversity, that just as we differ on the outside in terms of skin color
and height and body shape and so on, we also differ on the inside.
And these differences don't have to be dramatic differences,
differences that we might be tempted to label with this or that condition.

(23:39):
Now we're used to the neurodiversity now as well, but that's got a lot of connotations
typically about autism or ADHD or some other condition.
Whereas Whereas what I'm focusing on these days is the differences that we just
might not otherwise notice because there might be relatively small,

(24:02):
because we use language to the papers over these differences.
If we both say, yeah, you're wearing a red jacket. I mean, we can agree,
but maybe we're having different experiences of red.
And finally, of course, we, we just seem to see things as they are.
And because it seems to me that reality is just the way it is and my brain doesn't

(24:23):
have much to do with it, that's another bias against us recognizing how distinctive
our inner worlds might be.
And by fleshing out that idea, and one of the projects that I'm very deeply
involved in and excited about at the moment is a project called the Perception
Census we've been running, which has surveyed about 40,000 people,

(24:44):
each of whom has done between one or maybe several hours of experiments for
us, all trying to get at different ways of the uniqueness of individual experience.
So this project, we're still analyzing the data, but my hope is it's going to
paint a picture of how different our inner worlds are.

(25:06):
Scientifically, I think that's fascinating but there's also this cultural significance
that i think you hinted at that when we realize that we might live in perceptual
echo chambers to some extent.
Then that can cultivate within us a bit of humility about our own ways of seeing

(25:26):
and perhaps our own beliefs about the world and society, too.
If we can literally experience the same situation visually in different ways,
I think if we build really a better recognition of that, then that can be very
helpful in cultivating humility, empathy and platforms for communication and understanding.

(25:48):
That's a bit idealistic, I realize how it sounds. but I don't think it's nonsense.
I think there's some plausibility to it.
I would agree with that. And I like a little idealism.
We may not ever achieve perfect empathy and humility, but if we can,
if we can just move the needle a little bit, that's good for everybody.

(26:09):
Let's switch gears a little bit to talk about emotions, because I thought one
of the most fascinating portions of the book was talking about how we experience
an emotional state and assume that that emotional state drives bodily responses.
We feel scared. And so adrenaline is going to surge.

(26:30):
Cortisol levels are going to go up. My palms are going to be sweaty.
But you describe a situation in which the body has a response And then the brain
is guessing at which emotional state should match that bodily state.
It's reading the sweaty palms and the cortisol and the adrenaline and going,

(26:51):
oh, this person is scared.
Can you talk about that in a little more detail? Yeah, I'd love to.
I mean, it's an old idea again.
A lot of these ideas about the brain as a prediction machine actually go way
back. It's just that they're getting themselves on a much more solid footing
with the tools of modern neuroscience and psychology.

(27:11):
William James, who is one of the founders of psychology, along with a German
psychologist called Karl Langer, independently, they proposed this basic idea
that we don't cry because we're afraid. We're afraid because we cry.
The arrow of causality is reversed. so

(27:31):
it seems to us that we might
be in a situation let's say we we encounter i
know someone's running at us with a with a knife and we we see the situation
the visual experience of that situation causes us to feel fear and the experience
of fear sets in train all these bodily responses responses, cortisol,

(27:56):
adrenaline, so that we can either fight or flee.
Again, this might be how things seem. But the proposal from James and Langer
is that it's kind of the other way around so that we register,
our brains register the threat.
That automatically triggers the body to move towards this state of higher physiological

(28:19):
arousal, cortisol, adrenaline, the rest of it.
And it's the brain perceiving the body being in that state in the context of
this person with a knife rapidly approaching.
Would infers what's going on
as fear is now the the relevant experience
to have so the experience of fear doesn't cause the

(28:43):
body to be in a particular state it reflects the body
being in that state in the context of the
wider situation and so
thinking of things this way it emphasizes
as a continuity so that emotion is not
really completely distinct from visual

(29:03):
perception or other kinds of experience we can think of it as really resulting
from the same kind of process where the brain is still making predictions but
now the predictions instead of being about the causes of visual signals or auditory
signals the brain's predictions are now about sensory
information coming from the interior of the body in the context of the world,

(29:28):
sensory signals from the rest of the world.
So I like this way of thinking because it just is very parsimonious.
It suggests there's one core process happening.
The brain is making predictions, but depending on the target and function of
those predictions, we have different kinds of experiences, an emotion or a visual experience,

(29:49):
or perhaps an experience of our body as being
an object in the world or an experience of an action as
being freely willed but they're all kinds
of constructions and i think recognizing emotions in this
way can also be quite liberating and quite freeing because it can stop us falling
into the trap of reifying our emotions and if we feel anxious or angry or whatever

(30:15):
it might be if it's an aversive emotion opens a little bit of space where we
can recognize that that emotion is not.
A direct reflection of reality as it is. But it's a construction and it may
partly depend on the context.
And it's a state of what we're perceiving mainly as a state of the body.
It doesn't mean the emotion isn't appropriate and it certainly doesn't mean the emotions go away.

(30:39):
But it's very analogous to say how we were talking about color.
Now, when we understand more about color, it's not that we stop perceiving colors.
No, I still experience colors all over the place.
But there's another perspective on them now which is
enriching it's sort of color as is a
collaboration between my brain body in the world and the same goes for emotion

(30:59):
i think it opens that space where we have a little more flexibility in how we
respond to that emotion and that will also change how the emotion feels there
there are sort of emotional equivalents of this adelson's checkerboard the
same rush of adrenaline or cortisol can give rise to different emotional experiences,

(31:22):
depending on the context, depending on what the brain thinks is responsible
for the surge of cortisol and emotion.
Is it a scary situation or is it an exciting situation?
Depending on the context, we'll have different experiences, but the body is
in the same state or a very similar state. Yeah, it made me think of numerous things.

(31:42):
One that athletes, high performing athletes,
a lot of the time in a situation that makes them feel nervous when there's a
lot of pressure, they talk about a version of reframing that nervousness as
excitement because they know that will enhance performance.
And physiologically, those two states are very similar. And so as long as they're

(32:03):
aware of it, they're able to reframe that differently.
It also made me think about dating and how the you have these common tropes
of a date to a scary movie or a date to an amusement park where you go on a
roller coaster together.
And you talk about in the book how being frightened

(32:24):
is an aroused state and can often be tied
into sexual attraction and i i
found that really interesting so if you wanted to just just give
us a few more details on on that idea yeah i
think i honestly i don't know how much hard evidence there is for that it's
a little bit of a you know hard experiment to do but there were some experiments
back in the 1970s that tried to do exactly something like this when when ethical

(32:47):
guidelines on experiments were perhaps well definitely more lax than they are
are now and there's a famous experiment.
Done in Canada by Dutton and Aaron were the two psychologists and they had students walk over the.
Either a very rickety bridge, high above a gorge with a raging torrent and a

(33:10):
rocky floor, very scary, or over a bridge which was fairly boring,
very sturdy, very low over the water.
So a high arousal versus a low arousal inducer. And then at the end of the bridge,
they would get grilled by an attractive female with a clipboard.
The students were all male and i guess this

(33:33):
was the time where it was kind of an assumption of general heterosexuality whatever
and the quirk in the experiment was so
so the the girl with a questionnaire would ask various questions
but at the end of it would say and if you've got any further questions
here's my number and she was of course a stooge for
the whole experiment and what was really in question
was whether the people who went over the rickety

(33:55):
bridge would misinterpret the physiological arousal caused by the bridge as
attraction some kind of sexual chemistry romantic chemistry with the girl and
so the hypothesis was people who went over the scary bridge would make more calls,
following up and maybe asking asking the girl out and that's what they reported

(34:17):
now i mean it's an it's it's a fun experiment to talk about it's you know ethically
dubious in various obvious ways and it's very hard to replicate because you
can't really do that anymore.
But I think it's at least consistent with what you're saying about dating.

(34:37):
On the other example about athletes, so I'm no athlete, but I also find this
reframing useful in some contexts.
I've been trying to be more disciplined about cold water immersion over the
last couple of years and trying to jump in the sea here in Brighton when the water is very cold.

(34:59):
It's still very cold in May because it takes a long time to warm up or even
just taking a cold shower every morning.
And when you start doing this, it's very emotionally unpleasant.
You know, you feel you don't want to do it. And then it just feels like when
you're in the cold water, it's a horrible experience.
But then, you know, after a while, there's a reframing that becomes possible,

(35:23):
which is you realize that actually you're not going to die.
And so instead of these emotions
which are all bound up with one's expectations about
what cold water is going to be like and
you just pay attention to some of
the raw sensations like oh this is the experience of my
body getting cold then the whole

(35:44):
experience changes not just your interpretation of it
so i think this is important it's not i'm not saying that you can
have an experience but you think about it differently now the
context can change the experience so for me now
most of the time anyway getting into cold water
just feels different even though you know it still feels cold it's not that

(36:05):
it feels warmer it just is stripped away of some of the the optional i think
interpretations of it that it's going to be very unpleasant that it's going to induce,
you know, problems and is going to panic and so on.
And now it just feels cold and that's fine or fine-ish.

(36:25):
Sometimes it just still feels pretty unpleasant, but it's much less so than it was.
I started this morning off, since I'm in the Pacific time zone,
I started this morning off with a cold plunge.
I have a plunge at the house, and this is how I think about cold plunging.
It's easier to act your way into a new way of thinking than think your way into a new way of acting.

(36:50):
And I find that that cold plunge changes the bodily state and you can't help
but to be alert, aware, ready to go afterwards.
And and I think that that ties into what we're talking about here with these
bodily states drive our emotional state.
And cold plunging is a great way to get there.

(37:13):
Absolutely. I mean, sometimes you've just got to not think right.
You've just got to not think and do. do so you know that's
that's the strategy for things like this if you think about it
too much in advance you your motivation for
doing it just seems to get less and if you just automate it
it's like no i'm just going to do this and give myself no choice i mean i think
that's that's the way that you can then begin to bed in that that habit you

(37:37):
can change a habit and then it becomes like oh now it's beginning to feel different
so it becomes easier to do and you you can think about it and think,
okay, now I'm going to do it.
But the first few times, yeah, you have to turn off the chatter,
if you like, and just say, no, I'm going to not think about it.
I'm just going to not give myself any agency or free will and just go ahead.

(38:01):
And there's actually an aspect of the predictive brain that plays into this.
Another way that the brain can...
Can sort of do this dance between prediction, perceptual, top-down predictions,
and bottom-up sensory signals, is one way we've been talking about is the brain
basically updates its predictions.
But the other thing, of course, is we can act. We can act in the world and change

(38:22):
the data. We can change the sensory signals.
And so there's actually a theory of not just perception, but also of action in here.
Action becomes a self-fulfilling prediction about the movement and position
of our bodies so jumping into a cold plunge is like when you you know you really,

(38:43):
focus on self-fulfilling some predictions about the movement of the body in a way that becomes.
Somewhat decoupled from the larger context now what can psychedelics teach us about consciousness,
what a great deal and as a side note here i thought
it was very brave of you to talk about your

(39:04):
own experiences in the book because usually
someone who's a serious academic they they hide
that part of their lives or they shy away from sharing that and i
i appreciated that you talked about that openly and would
just love to hear more about that well that's funny you put
it like that because i was i was um remembering a conversation
between a philosopher who you know

(39:26):
who i respect greatly a guy called thomas metzinger
who's a philosopher of mind and i think he was talking to Sam Harris who
asked him something similar and his response
was well you know there are serious
consciousness scientists and there are non-serious consciousness scientists
and sort of left it at that but but I you know I think that for me it sort of

(39:47):
felt that I was learning a lot about psychedelics from the third person but
there was it was important to register that knowledge with the first person experience itself,
but what can we learn? Well, on the.
On one level, an awful lot. I mean, one of the amazing things about psychedelics

(40:08):
from a perspective of a consciousness researcher is that you have this relatively
small change, small intervention.
You give a particular pharmacological compound.
We know roughly where it binds to in the brain. It's mechanically where it ends
up, the parts of the brain where there are more receptors.

(40:29):
And then there is this massive change in conscious experience.
So experimentally, it's a very interesting intervention.
And it reveals, in a sense, how constructed our experiences are,
because many things can change in psychedelics, in different psychedelics,
of course, have different effects.

(40:51):
But for instance, a common effect is ego dissolution, our experience of being
a well-defined self that's separate from the world and separate from other selves
can go away, to some extent, or even in some cases, perhaps entirely.
What do we learn from that? Well, I think we learn that the experience of being
a self is not something to take for granted.

(41:12):
It's something that the brain is actively constructing all the time.
So psychedelics for me reveal what is this surprising range of experiences that we can have.
And for me, reveals how essential and
how deeply our brain is implicated in constructing

(41:33):
all of the experiences we have now there
are other ways that people interpret psychedelic
experiences which i find less useful to think about which is that the content
of a psychedelic experience instead of revealing the range and possibility and
what we should not take for granted as revealing core insights into the way reality really is.

(41:59):
And that's different. So if you take a psychedelic experience literally as sort
of throwing off our filters and saying that this is real, this is more real
than everyday experience, then I think you got it the wrong way around.
For me, it's shedding light on how much is constructed.
It's not giving us sort of unique, unfiltered access to reality as it really is.

(42:25):
Another example I think helps
clarify this that people can often report out-of-body experiences
you know they see themselves from somewhere that's
out external to their body or perhaps floating
off in in the air or in space what should
we learn from that i mean this might be from psychedelics it might be from
you know other situations too people can have these experiences in operating

(42:49):
theaters or just brain stimulation or many other reasons well one interpretation
is that your consciousness has in fact left your body and gone flying around
that would be to take the experience literally,
that's really probably not true you know they're very hard to explain that and

(43:10):
of course how well how would you see anything without eyes it just doesn't make
sense in in many different ways.
But if you take the experience of an out-of-body experience,
not literally, but seriously, what it's telling us, I think,
is that the very experience of a first-person perspective is not to be taken for granted.
The brain is always constructing it.

(43:32):
And sometimes under some situations, it constructs it in a very strange way
where the brain is saying, no, experience is coming from a perspective which is not in the body.
I think that's the right way to experience. And it's completely different because
in the second case, we're still saying, acknowledging that the brain is where
consciousness is happening, but the content of consciousness now we realize is.

(43:57):
Something we might have taken for granted that, well, of course,
we will see the world from where their brain is because that's where the brain is.
But no, the brain is figuring out what the best location for the first person
is, and it might not always be in the brain. But it's going to depend.
And just to finish, draw a loop on it. It's going to depend a lot,
I think, on your prior beliefs about nature of consciousness.

(44:19):
If you are partial to something like panpsychism,
that consciousness is everywhere and part of everything then you might be more
likely to interpret a psychedelic experience differently from if you are someone
like me who is more of a materialist that i think consciousness is a property
of biological brain-like systems,

(44:40):
so there's going to be a lot of variety as well and i also just wanted to emphasize that,
this is all separate from the value the personal value that someone might take
from it so So, you know, somebody might, after a psychedelic experience,
interpret it in a different way to
how I would as like an insight that consciousness suffuses the universe.

(45:03):
You know, that would be a different conclusion than I would reach,
but it still might be personally very beneficial for them.
And that's a whole other, of course, aspect of psychedelics.
It's potential for therapeutic deployment, for clinical use,
for enhancement of well-being.
And here I think there is a lot of potential, but I think the data is a bit mixed.
And we need to be a little careful from the

(45:25):
pendulum swinging from one extreme where psychedelics
were illegal and
neglected by the mainstream medical scientific
establishment to the other extreme where
you know now there's there's huge enthusiasm and excitement and
a lot of money into psychedelic startups and so on i

(45:45):
think there is a lot of potential but i also
think there's no silver bullet speaking of consciousness arising from biological
systems can ai become conscious in your estimation in my estimation i think
it's extremely unlikely i am a little bit more.

(46:09):
I'm a bit of an outlier i think among many
colleagues of mine in neuroscience but especially in
when you hear people more deeply
in the tech world i think as a general belief that ai
is on the road to consciousness i think that's largely mistaken and
i think this is true for several reasons firstly there's just this background
assumption that's very common in many corridors

(46:33):
doors of academia and tech that consciousness is
some kind of computation you get
the computations right consciousness will happen but for
me this is a massive assumption like why should we think that the metaphor of
the brain as a computer has been very useful but ultimately it's just a metaphor

(46:54):
and the more you look at things like brains the less like a computer they seem theme.
In a computer, you've got this hard distinction between the hardware and the software.
In a brain, you've got nothing like that between the mindware and the wetware of a brain.
In a brain, it's very, very hard to strip out what it does from what it is.

(47:15):
But computers tend to work because they make that distinction very sharp.
So even if consciousness is a kind of computation, it might not be the kind
of computation that can be done in things other than brains.
But i think even more deeply it's probably not a form of computation anyway
you know brains are very complex systems but they're not necessarily kinds of

(47:41):
biological computers so i think ai,
is certainly on the path to convincing us that it's conscious and can simulate,
conscious systems we can model it i mean we can simulate the brain on a computer
but we can simulate anything on a computer.
That's what computers are good at. And if we have a simulation of a weather

(48:02):
system, we don't get confused about the fact that it's not wet or windy inside
the weather forecasting computer. We know it's just a simulation.
But for computer models of the brain, like we see in AI, we might start to get
confused and think, oh, it's not just a simulation.
It's actually the thing itself. But I think there are many reasons to doubt that.

(48:24):
And there are many reasons why we make, why we're tempted to make those kinds of attributions.
I mean, we're very anthropocentric, anthropomorphic creatures.
We see the world through the lens of being human.
And we project human qualities into things on sometimes rather rather flimsy evidence.
So language is a very, very powerful lever in this domain.

(48:48):
When things speak to us, we tend to project things like understanding consciousness
into them. The current wave of language models has been very powerful here.
But I really think the tendency to attribute consciousness to these kinds of AI,
it tells us more about our human psychological
biases s's than it does about

(49:08):
what's likely to be happening in these systems so
you know i see a lot of obstacles to ai being conscious but i
see large challenges for us
anyway when we're surrounded by systems that give
us the impenetrable impression of being conscious even
though we might at some level think that they aren't yeah especially when a

(49:31):
lot of the interfaces that that are being created by new companies now seem
designed to make those large language models seem more like a person,
like a friend that you're talking to,
that will get tricky for people to parse out what they're dealing with there.
It's already getting tricky.
I mean, there's already cases of people behaving in ways that are not good for

(49:57):
them on the basis of interacting with language models and believing that the
language models really care about them.
And there are questions here for the people developing these kinds of things.
There's this sort of assumption that.
AI, especially among the more evangelistic segments of AI and tech,
that the goal is to develop systems that are human-like.

(50:20):
But it's not clear that that's what we should want.
A mentor of mine who sadly died a few weeks ago, the philosopher Daniel Dennett,
said many years ago, but kept saying again, I think for very good reasons,
that we should we should always remember that we should treat AI as tools rather

(50:40):
than colleagues and always remember the difference.
And that has important implications for how we design AI.
Maybe we don't want to design AI to be as similar to us in all possible ways.
Maybe we design systems that complement rather than replace us.
And for me, that's a path towards getting more of the positives from this new

(51:06):
technology and avoiding some of the potential negatives.
Now, I did want to ask, because earlier you mentioned different frameworks for
thinking about psychedelics or different frameworks for thinking about consciousness.
Where does your framework for
consciousness diverge from Donald Hoffman's framework for consciousness?

(51:30):
Because I spoke to him and really enjoyed our conversation,
but he has a much different way of looking at all of this, talking about consciousness
basically giving rise to an interconnected consciousness,
giving rise to space and time, which is a much different way to approach all

(51:53):
of this than a materialist perspective,
which is that consciousness arises from biological
properties individually if i'm if
i'm summarizing that correctly and if i'm not please let me
know yeah i mean more or less i think my perspective
is bio is that there's something special about biological systems but i don't
know that for sure and the claim in materialism more broadly is doesn't is not

(52:18):
restricted to biological systems it says consciousness is a property of matter
of some form so donald and I've had many conversations. I always enjoy talking to him too.
I always learn something. And we agree up to a point.
We agree that the world that we experience is not the world as it is.
It's a kind of construction.

(52:40):
And the relationship or the way in which we encounter the world is something
evolution has tuned to be useful, not to be accurate.
So those are two large points of consensus.
The first point of disagreement I think is he's very fond of this kind of user
interface metaphor where the world that we experience is some kind of interface

(53:02):
that's useful for the self as the user.
Now, I don't like that way of thinking because I think the self is part of the construction too.
There's no self that's perched inside the brain, kind of reading out perceptions
and figuring out what to do.
That's a kind of inner homunculus view that I think is unhelpful.

(53:23):
But I think the more fundamental place we diverge is what can be said about
the nature of reality on the basis of thinking this way now don takes it all
the way that the level of indirectness is such that,
for him it makes sense to say that reality is
fundamentally constituted by conscious agents

(53:44):
of some form or another and you know i don't want to pretend i
can accurately summarize his view on
this but he goes to this
to that far and says okay that's
fundamental claims about the nature of
reality and space and time are also aspects of construction so i just i suppose

(54:04):
i'm a little more conservative than than don on this i think in a sense more
radical that the self is part of the construction it's not the user and the
interface i think that's a bit unhelpful.
But i don't see any any license in thinking this way that that that means we
can say anything about the ultimate nature of reality.

(54:27):
Now, I do think that things like the way we experience time and space are also,
to some extent, constructions.
Immanuel Kant said this, said as much hundreds of years ago.
But he also said, Kant had said that, well, there's this noumenon,
there's this nature of reality, and we never have direct access to it. But it is there.
And I guess I'm a sort of some minor descendant of that way of thinking,

(54:50):
that there is objective reality but the way
we experience it is a construction and i
just don't think we're licensed to say that the natural reality is
made of conscious agents or otherwise you know i still
find materialism to be a good working assumption i don't know if it's true but
we certainly haven't exhausted thinking of things this way and it matters because

(55:12):
if you if you adopt that perspective just as a working assumption you tend to
do experiments that shed light on the phenomenon.
Now it's a good assumption in the sense that it
generates interesting testable predictions about how the brain
works and how it shapes our our reality
and if you start talking about conscious agents
as the fundamental nature of reality i'm yet to be

(55:34):
convinced it's a use it leads to many useful experiments it's not to say it's
wrong it just i i think it detaches itself from the power of the scientific
method has always relied on this balance of thinking creatively and and being
skeptical about the story that's told about things,
but also remaining in this kind of space of adjacency, the adjacent possible where, where.

(56:01):
You iterate and you test something, you come up with new ideas,
you test something else, but you still want to be more or less in the domains of testability.
Maybe not for everything, but at least for some things.
So yeah, we end up differing, I think, a lot about our claims about reality.

(56:22):
But in practice, in how we understand the brain as a prediction machine, perhaps not so much.
Yeah, I think there is a lot of overlap between your
thinking on this with his and I
for one am glad both of you are doing the work
you're doing because I think it's provocative and
interesting and coming at it from two different perspectives and anyone that

(56:46):
is interested in consciousness and what it's like to be to really think and
examine what it's like to be a conscious agent would benefit from studying your
work and going from there.
There is an overlap with me and Don, but there are also many other theories
of consciousness that are very different in other ways too.

(57:08):
And they might be more similar to my way of thinking in the sense that they
share a basic materialist foundation, but then they'll differ greatly in what
they think the mechanisms of consciousness are.
There's this global workspace idea championed by Bernie Baars and Stan DeHaan.
Consciousness is to do with global broadcast information in the brain.

(57:30):
There's the really challenging integrated information theory of consciousness,
which is probably the most ambitious theory out there.
And it has implications that consciousness is much more widespread than we might
think, but it takes a very different perspective again, and, and many others too.
And I think this is an exciting time in the field, because we,

(57:51):
we have a number of theories now that.
That explain different things, that make different assumptions,
but there's an effort to try and compare them, to try and test them against each other.
And, you know, I've seen over the last 10 or 20 years, these things develop substantially.
And I think the next period of time is going to be really exciting because these

(58:13):
theories and the experimental methods we have now are getting to the point where
we can meaningfully compare contrasting ideas about the nature of consciousness.
And of course, that's where science really takes off when you can start comparing
and disambiguating different theories.
When as that process moves forward, do you think slowly but surely this great

(58:39):
mystery in science of where consciousness arises, do you think that is solvable?
I think it's dissolvable. I think what's most likely to happen is that as progress is made,
then there won't be one day where we wake up to the news that scientists have
solved the problem of consciousness and here it is.

(59:03):
Partly because we don't even know what a solution would look like.
I think much more likely is something that happened previously with our understanding of life.
Wasn't that one day somebody discovered the secret of life? I mean,
you could argue that Watson and Crick discovered and Rosalind Franklin discovered
the structure of DNA, but that's not solving the problem of life.

(59:23):
The problem of life had been largely solved before then, that we collectively
realized that it wasn't a single magic thing, that it was many different processes
that particular systems, living systems, tend to do.
And our nature of the problem changed
just as much as our grasps on the solutions to the problems of life.

(59:48):
And so I think consciousness is likely to follow that trajectory rather than
the eureka kind of trajectory.
That as we understand more, we won't solve the problem as it seems to us now,
but the nature of the questions we ask will change.
And so the problem of consciousness will gradually seem

(01:00:10):
less of a problem than it does and
this is already happening and this is what does keep me going if i was relying
on there to be a single eureka solution and a race to find it yeah i think that
would be for me anyway a bit demotivating what what i enjoy about the field
is that even without fully solving the problem.

(01:00:32):
What we're discovering is both interesting and useful. And we've talked about
this when we talked about perception, you know, it's very useful in society
to know about these things, but the nature of the problem is also changing.
You know, I think about consciousness in a different way now than I did 10 years, 20 years ago.
And so that is an optimistic take, but you know, we need, we need to be a bit optimistic.

(01:00:53):
Otherwise we wouldn't do anything, but I also think it's reasonably likely.
And there is a world where, yeah, we have a much more satisfying understanding
of consciousness, even if at the end of the day, there's still a little bit
of mystery that remains.
Dr. Seth, if anybody wants to learn more about your work, there's the book,

(01:01:13):
of course, Being You, A New Science of Consciousness.
Where else can they go to learn more about what you're doing?
Oh, thank you for mentioning the book. That's definitely the place to start.
Then that's a couple of years old now, but it's still very current.
But for the latest stuff, I have a website, annielseth.com. So that's reasonably up to date.

(01:01:39):
So you can find out more about research in my group and podcasts like these will be posted there.
And I'm still, for my sins somewhat on Twitter or X where you can follow me on Anil K.
Seth. So with a K in the middle for my middle name, Anil Seth was already taken.

(01:02:00):
So those would be the places to find out more. Great. Well, thank you so much for coming in today.
I know you have places to be people to talk to and I, and I want to respect
your time, but honestly, I could talk to you all day.
I just was some of the little birdwalks that you take in the chapters that just

(01:02:25):
reveal how you process the world and think about things.
And I personally hope there's another book out there in the future because I
think everybody would benefit from a little more Dr. Seth out there in the world.
That's very nice of you to say so. Yeah, I'm sure there'll be another book.
I haven't started writing it yet, but I think these things take time.

(01:02:47):
Thanks a lot. It's been great. I enjoyed talking to you. I appreciate your time,
too. So thank you very much, Nick.
Okay, everybody. Until next time, ask questions, don't accept the status quo, and be brave.
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