All right, so today we're gonna be tackling something
pretty huge, consciousness.
Yeah.
I mean, it's like the foundation of everything, right?
If we weren't conscious, there'd be no world,
no self, no nothing.
Totally, like without consciousness,
there's literally no experience at all.
So for this deep dive, we're gonna be exploring
some ideas from Anil Seth.
Oh, cool.
He's a neuroscientist who gave this awesome TED talk.
Yeah, I've seen that one.
And he's got this really mind-blowing way
of looking at how consciousness works.
Right, Seth's approach is super interesting
because he kind of turns the whole perception thing
on its head, you know?
Okay, so instead of just taking in the world as it is,
you're saying our brains are actually creating
their own version of reality.
Exactly, he talks about the brain as a prediction engine.
Like think about it, our brains are stuck
inside our skulls.
No direct access to the outside world.
All it gets are these streams of sensory data,
like light hitting your eyes, sound waves in your ears.
It's like almost like being in a sensory deprivation tank.
Kinda, but instead of nothingness,
it's like this constant bombardment of raw data
that our brains have to decode.
Oh, wow, yeah.
So how does the brain make sense of all that chaos?
Well, Seth says it uses its past experiences,
its knowledge, to make these informed guesses.
So it's not just absorbing, it's actively trying
to predict what's gonna happen next.
Bingo, and those predictions actually shape
how we perceive the world.
That's wild.
It is, like remember that visual illusion
with the two shaded squares?
Oh yeah, the ones where they're the same shade of gray,
but look totally different because of the shadow, right?
Yeah, that's the one.
Even when I know they're the same color,
my brain's like, nope, they're different.
Right, it's like a trick, but not really.
Yeah.
It's actually your brain making a prediction.
It knows shadows make things appear darker,
so it adjusts what you see even though the actual information
is the same.
So our brains are kind of filling in the blanks
based on what they expect to see.
Totally, they're creating this more coherent,
more predictable world based on our past experiences.
Makes sense, but also kind of freaky
when you think about it.
Oh yeah, another great example is that distorted audio clip,
you know the one?
Remind me.
Where all you hear is noise at first,
and then someone tells you what the sentence is.
Oh, right, right, and then suddenly you can hear the words,
even though the sound hasn't changed.
Exactly, because once you know what to expect,
your brain uses that information to fill in the gaps
and make sense of the noise.
I remember thinking, like how did my brain not hear that
before?
Right, it shows how powerful those predictions can be.
So, okay, our brains are these prediction machines,
constantly making these educated guesses.
But where does consciousness actually fit into all of this?
Like how does that work?
Well, here's where Seth really drops the bombshell.
He calls perception a kind of controlled hallucination.
Wait, hold on, you're saying everything we experience,
see, hear, feel, is a hallucination?
In a way, yes.
It's not that the world isn't real,
but our experience of it is a construction
created by our brains.
Whoa, okay, so does that mean reality isn't real at all?
Not quite.
The key here is controlled.
These hallucinations are constantly being checked
against real world feedback.
So we're not just hallucinating whatever we want,
our brains are still bound by the laws of physics and stuff.
Okay, so it's like our brains are making
this virtual reality simulation,
but it's one that's constantly being adjusted
based on what's actually happening around us.
Yeah, that's a great analogy.
It works because for the most part,
the world is pretty predictable.
We've evolved to anticipate those regularities
and our brains have become really good
at making these models.
Okay, this is making me think about people
who have actual hallucinations with schizophrenia
or things like that.
Is that their prediction engine going off the rails?
It's complicated, but there are definitely
some interesting connections.
Actually, Seth did this study using VR
in that Google Deep Dream algorithm, have you heard of that?
Yeah, you would.
They basically turned the campus at Sussex University
into this bizarre psychedelic world
filled with dogs everywhere.
Wait, seriously?
Like dogs everywhere you looked.
Yeah, it was meant to simulate what happens
when predictions get too strong
and overwhelm the actual sensory data.
I get it.
Like when that happens,
you can start experiencing things that aren't really there.
So in a way, we're all hallucinating all the time.
Kind of.
But most of us are good at keeping it in check.
Exactly.
We agree on our hallucinations
and that's what we call reality.
Okay, I think I'm starting to get this.
Good, but here's where things get even wilder.
Seth also argues that the self,
like our experience of being a unique me
is also a controlled hallucination.
Now, hold on a minute.
Illusions, okay, I can sort of wrap my head around that.
But myself, this whole sense of me is a hallucination.
It might sound crazy, but think about it.
How do you know you have a body?
How do you experience the world from your perspective?
How do you feel like the same you over time?
I mean, I guess I never really is dubbed to think about it.
Right, and what's fascinating is that
those different parts of the self
can actually come apart.
There are people with brain injuries, for example,
who lose their sense of body ownership
or feel like their actions aren't their own.
So you mean this me feeling isn't as solid as it seems?
Exactly, it's this construction
that's constantly being updated by our brains.
So it's like we're making up our sense of self too.
In a way, yes.
And like any other perception,
it's based on predictions and inferences.
Okay, I need an example here
because this is getting pretty out there.
Have you ever heard of the rubber hand illusion?
Rubber hand illusion, okay.
You mentioned it before, but to be honest,
I have no idea what you're talking about.
It's pretty trippy.
Basically it's this experiment
where they hide your real hand
and put this fake rubber hand in front of you
and then they stroke both hands at the same time
with the brush, but you're looking at the rubber hand.
So it'd be like seeing this fake hand being touched
but feeling it on my real hand,
that sounds kind of weird.
It is, what happens is after a while,
people start to feel like the rubber hand
is actually their own hand.
Really?
Just from seeing and feeling the touch at the same time.
Yeah, it's crazy, right?
Well, like my brain wouldn't know
which hand was real anymore.
Exactly, it shows how the brain tries to make sense
of conflicting information.
Makes you wonder what else our brains
are like tricking us into believing.
Oh, all the time.
But in this case, it's because your brain is trying
to create this single coherent experience.
Even if that means kind of bending the rules a bit.
So because I'm seeing the rubber hand being touched
and feeling it on my skin, my brain's like,
well, that must be my hand then.
Yep, it prioritizes what makes sense visually
even if it contradicts your internal sense
of where your hand is.
Internal sense, is that like proprioception?
Exactly, proprioception is your body's sense
of where it is in space.
Like how you know where your arms and legs are
without having to look.
It comes from sensors in your muscles and joints.
Okay, so in the rubber hand illusion,
what I'm seeing and feeling overrides that internal sense.
Exactly, the visual and tactile information
is just so strong it takes over.
Wow, that's pretty wild.
And there are different versions of this illusion, right?
Oh yeah, there's one where they make the virtual hand
flash in sync with your heartbeat.
No way!
And that makes it feel even more like your own hand.
Yeah, because now it's connected to your internal rhythms,
not just external sensations.
Okay, this is starting to creep me out a little bit.
I know, it's kind of freaky.
It's like how much control do we even have
over our sense of self?
It's a good question, but this malleability
isn't necessarily a bad thing.
It's actually what allows us to adapt to new situations.
Okay, yeah, that makes sense.
Like our sense of self needs to be flexible to some extent.
This is making me super aware of my body right now.
Yeah.
Like suddenly I can feel everything.
It's funny how learning about this stuff
can change how you experience your own body, isn't it?
Totally.
Yeah.
But speaking of body stuff,
you mentioned something earlier, interoception.
Oh, right.
That's another crucial piece of the puzzle
when it comes to understanding the self.
Okay, break it down for me.
Basically, interoception is our sense
of the internal state of our bodies.
So things like your heart rate, your breathing,
temperature, hunger.
So not the outside world, but what's going on inside?
Exactly.
It's about sensing what's happening inside us,
not outside of us.
Okay, so like when my stomach growls, that's interoception.
Yeah.
Or feeling your heart racing when you're nervous.
Right.
Yeah.
But why is that so important for the self?
Because it's all about keeping us alive.
Think about it.
We don't usually sense our individual organs
unless something's wrong, right?
That's true.
I guess I don't walk around feeling my spleen or anything.
Right.
Interoception is less about like knowing every detail
of your insides and more about providing feedback
to keep everything running smoothly.
So it's kind of like the behind the scenes stuff
that keeps our bodies going.
Exactly.
It's about regulation, maintaining that balance
with the call homeostasis.
I'm starting to see how this all ties back to the self.
Yeah.
It's like our basic experience of being a body
is rooted in these internal signals.
It's like we predict ourselves into existence
from the inside out.
That's a great way to put it.
So if this whole sense of self is a controlled hallucination,
what does that mean for like everything else?
Like what?
Like how we think about mental health,
artificial intelligence, even just what it means
to be human.
Those are some big questions.
Ones we should definitely explore further.
Okay, so we've been talking about this idea
that consciousness, even our sense of self
is like this best guess that our brain makes.
Right.
Based on predictions and sensory information.
But what are the big implications of all this?
Where do we even go from here with this knowledge?
Well, Seth talks about how this view of consciousness
could really change the way we think about mental health.
Oh, interesting.
He suggests that a lot of mental health conditions
could be understood as prediction errors.
Prediction errors, like when those predictions go wrong.
Exactly, like when the brain's predictions
about the world or even about itself
don't match up with reality.
That's fascinating.
So instead of just focusing on the symptoms,
you could look at what's causing those prediction errors
in the first place.
Yeah, it could lead to completely new ways
to treat and prevent mental health issues,
not just manage them.
Can you give me an example?
How would a prediction error look in real life?
Sure, think about someone with, say, social anxiety.
Okay.
They might constantly predict that social interactions
will go badly, so they avoid them altogether.
So their brain is basically creating
this distorted model of social reality
based on faulty predictions.
Oh, wow, I get it.
And therapy could then focus on helping them recalibrate
those predictions.
So they can actually engage with people
without all that fear and anxiety.
Exactly.
By understanding these underlying mechanisms,
we could develop much more targeted
and effective treatments.
That's pretty incredible.
It really changes how you think about mental health.
Yeah, it's a whole new perspective.
But what about artificial intelligence?
Everyone's talking about AI these days.
Does this whole controlled hallucination thing
tell us anything about whether AI could ever become conscious?
Well, Seth makes this really important point.
What's that?
That consciousness isn't just about processing information.
It's about being a biological organism.
Our experience of consciousness is deeply tied
to the biological stuff that keeps us alive.
So just building more powerful computers
won't necessarily make them conscious.
Exactly.
It's not like flipping a switch.
That's kind of a relief, to be honest.
Yeah.
The whole idea of sentient robots always
freaked me out a little.
I get it.
But if consciousness is so tied to biology,
does that mean humans are the only ones who have it?
What about animals?
Another good question.
Seth is really clear that human consciousness is just
one way to be conscious.
OK.
There's probably a huge range of different kinds
of consciousness out there.
And other creatures likely have their own unique experiences.
So the way we experience the world
might be just one tiny version of consciousness out of many.
Exactly.
Who knows what other forms of consciousness might exist?
It's kind of mind blowing, right?
It really is.
It makes you realize how little we actually know.
So just to recap, we've learned that our brains
are these prediction machines, creating this model of reality
that we experience as consciousness.
And that includes our sense of self,
which is also kind of a controlled hallucination tied
to our biology.
And this whole view has big implications
for understanding things like mental health, AI,
and the vast spectrum of possible consciousnesses out there.
It's a lot to take in, but it's also super exciting.
I know, right?
It makes you question everything you
thought you knew about, like the nature of reality.
It really does.
And Nilseth's work has definitely given me
a whole new way of looking at what it means to be human,
to experience the world.
It's pretty remarkable.
And it leaves us with this question.
If our experience is so constructed,
so dependent on our brains, what other aspects of reality
might we be completely missing?
That's a great question, and one that I think
will stick with me for a while.
Thanks for joining us on this deep dive, everyone.
We'll see you next time for another fascinating exploration.