back to indexChristof Koch: Consciousness | Lex Fridman Podcast #2
link |
As part of MIT course 6S099 on artificial general intelligence, I got a chance to sit
link |
down with Christoph Koch, who is one of the seminal figures in neurobiology, neuroscience,
link |
and generally in the study of consciousness.
link |
He is the president, the chief scientific officer of the Allen Institute for Brain Science
link |
From 1986 to 2013, he was a professor at Caltech.
link |
Before that, he was at MIT, he is extremely well cited, over 100,000 citations.
link |
His research, his writing, his ideas have had big impact on the scientific community
link |
and the general public in the way we think about consciousness, in the way we see ourselves
link |
He's the author of several books, The Quest for Consciousness and Neurobiological Approach,
link |
and a more recent book, Consciousness, Confessions of a Romantic Reductionist.
link |
If you enjoy this conversation, this course, subscribe, click the little bell icon to make
link |
sure you never miss a video, and in the comments, leave suggestions for any people you'd like
link |
to see be part of the course or any ideas that you would like us to explore.
link |
Thanks very much and I hope you enjoy.
link |
Okay, before we delve into the beautiful mysteries of consciousness, let's zoom out a little
link |
bit and let me ask, do you think there's intelligent life out there in the universe?
link |
Yes, I do believe so.
link |
We have no evidence of it, but I think the probabilities are overwhelming in favor of
link |
Given a universe where we have 10 to the 11 galaxies and each galaxy has between 10 to
link |
the 11, 10 to the 12 stars and we know most stars have one or more planets.
link |
So how does that make you feel?
link |
It still makes me feel special because I have experiences.
link |
I feel the world, I experience the world and independent of whether there are other creatures
link |
out there, I still feel the world and I have access to this world in this very strange
link |
compelling way and that's the core of human existence.
link |
Now, you said human, do you think if those intelligent creatures are out there, do you
link |
think they experience their world?
link |
Yes, if they are evolved, if they are a product of natural evolution as they would have to
link |
be, they will also experience their own world.
link |
The consciousness isn't just human, you're right, it's much wider.
link |
It may be spread across all of biology.
link |
The only thing that we have special is we can talk about it.
link |
Of course, not all people can talk about it.
link |
Babies and little children can talk about it.
link |
Patients who have a stroke in the left inferior frontal gyrus can talk about it, but most
link |
normal adult people can talk about it and so we think that makes us special compared
link |
to let's say monkeys or dogs or cats or mice or all the other creatures that we share the
link |
planet with, but all the evidence seems to suggest that they too experience the world
link |
and so it's overwhelmingly likely that aliens would also experience their world.
link |
Of course, differently because they have a different sensorium, they have different sensors,
link |
they have a very different environment, but the fact that I would strongly suppose that
link |
they also have experiences.
link |
They feel pain and pleasure and see in some sort of spectrum and hear and have all the
link |
Of course, their language, if they have one, would be different so we might not be able
link |
to understand their poetry about the experiences that they have.
link |
So in a talk, in a video, I've heard you mention Siputzo, a dachshund that you came up with,
link |
that you grew up with, it was part of your family when you were young.
link |
First of all, you're technically a Midwestern boy.
link |
But after that, you traveled around a bit, hence a little bit of the accent.
link |
You talked about Siputzo, the dachshund, having these elements of humanness, of consciousness
link |
that you discovered.
link |
So I just wanted to ask, can you look back in your childhood and remember when was the
link |
first time you realized you yourself, sort of from a third person perspective, are a
link |
This idea of stepping outside yourself and seeing there's something special going on
link |
I can't really actually – it's a good question.
link |
I'm not sure I recall a discrete moment.
link |
I mean, you take it for granted because that's the only world you know.
link |
The only world I know and you know is the world of seeing and hearing voices and touching
link |
and all the other things.
link |
So it's only much later at early – in my underguided days when I enrolled in physics
link |
and in philosophy that I really thought about it and thought, well, this is really fundamentally
link |
very, very mysterious and there's nothing really in physics right now that explains
link |
this transition from the physics of the brain to feelings.
link |
Where do the feelings come in?
link |
So you can look at the foundational equation of quantum mechanics, general relativity.
link |
You can look at the periodic table of the elements.
link |
You can look at the endless ATGC chat in our genes and nowhere is consciousness.
link |
Yet I wake up every morning to a world where I have experiences.
link |
And so that's the heart of the ancient mind body problem.
link |
How do experiences get into the world?
link |
So what is consciousness?
link |
This is any experience.
link |
Some people call it subjective feeling.
link |
Some people call it phenomenology.
link |
Some people call it qualia of the philosopher.
link |
But they all denote the same thing.
link |
It feels like something in the famous word of the philosopher Thomas Nagel.
link |
It feels like something to be a bat or to be an American or to be angry or to be sad
link |
or to be in love or to have pain.
link |
And that is what experience is, any possible experience.
link |
Could be as mundane as just sitting in a chair.
link |
Could be as exalted as having a mystical moment in deep meditation.
link |
Those are just different forms of experiences.
link |
So if you were to sit down with maybe the next, skip a couple generations, of IBM Watson,
link |
something that won Jeopardy, what is the gap, I guess the question is, between Watson, that
link |
might be much smarter than you, than us, than any human alive, but may not have experience,
link |
Well, so that's a big, big question.
link |
That's occupied people for the last, certainly last 50 years since we, you know, since the
link |
advent, the birth of computers.
link |
That's a question Alan Turing tried to answer.
link |
And of course he did it in this indirect way by proposing a test, an operational test.
link |
But that's not really, that's, you know, he tried to get at what does it mean for a person
link |
to think, and then he had this test, right?
link |
You lock them away, and then you have a communication with them, and then you try to guess after
link |
a while whether that is a person or whether it's a computer system.
link |
There's no question that now or very soon, you know, Alexa or Siri or, you know, Google
link |
now will pass this test, right?
link |
And you can game it, but you know, ultimately, certainly in your generation, there will be
link |
machines that will speak with complete poise that will remember everything you ever said.
link |
They'll remember every email you ever had, like Samantha, remember in the movie Her?
link |
There's no question it's going to happen.
link |
But of course, the key question is, does it feel like anything to be Samantha in the movie
link |
Or does it feel like anything to be Watson?
link |
And there one has to very, very strongly think there are two different concepts here that
link |
There is the concept of intelligence, natural or artificial, and there is a concept of consciousness,
link |
of experience, natural or artificial.
link |
Those are very, very different things.
link |
Now, historically, we associate consciousness with intelligence.
link |
Because we live in a world, leaving aside computers, of natural selection, where we're
link |
surrounded by creatures, either our own kin that are less or more intelligent, or we go
link |
Some are more adapted to a particular environment.
link |
Others are less adapted, whether it's a whale or dog, or you go talk about a paramecium
link |
And we see the complexity of the nervous system goes from one cell to specialized cells, to
link |
a worm that has three nets, that has 30 percent of its cells are nerve cells, to creature
link |
like us or like a blue whale that has 100 billion, even more nerve cells.
link |
And so based on behavioral evidence and based on the underlying neuroscience, we believe
link |
that as these creatures become more complex, they are better adapted to their particular
link |
ecological niche, and they become more conscious, partly because their brain grows.
link |
And we believe consciousness, unlike the ancient, ancient people thought most, almost every
link |
culture thought that consciousness with intelligence has to do with your heart.
link |
And you still see that today.
link |
You see, honey, I love you with all my heart.
link |
But what you should actually say is, no, honey, I love you with all my lateral hypothalamus.
link |
And for Valentine's Day, you should give your sweetheart, you know, hypothalamus, a piece
link |
of chocolate and not a heart shaped chocolate.
link |
Anyway, so we still have this language, but now we believe it's a brain.
link |
And so we see brains of different complexity and we think, well, they have different levels
link |
They're capable of different experiences.
link |
But now we confront the world where we know where we're beginning to engineer intelligence.
link |
And it's radical unclear whether the intelligence we're engineering has anything to do with
link |
consciousness and whether it can experience anything.
link |
Because fundamentally, what's the difference?
link |
Intelligence is about function.
link |
Intelligence no matter exactly how you define it, sort of adaptation to new environments,
link |
being able to learn and quickly understand, you know, the setup of this and what's going
link |
on and who are the actors and what's going to happen next.
link |
That's all about function.
link |
Consciousness is not about function.
link |
Consciousness is about being.
link |
It's in some sense much fundamental.
link |
You can see this in several cases.
link |
You can see it, for instance, in the case of the clinic.
link |
When you're dealing with patients who are, let's say, had a stroke or had were in traffic
link |
accident, et cetera, they're pretty much immobile.
link |
Terri Schiavo, you may have heard historically, she was a person here in the 90s in Florida.
link |
Her heart stood still.
link |
She was reanimated.
link |
And then for the next 14 years, she was what's called in a vegetative state.
link |
So there are thousands of people in a vegetative state.
link |
So they're, you know, they're, you know, they're like this.
link |
Occasionally, they open their eyes for two, three, four, five, six, eight hours, and then
link |
They have sleep wake cycle.
link |
Occasionally, they have behaviors.
link |
They do like, you know, but there's no way that you can establish a lawful relationship
link |
between what you say or the doctor says or the mom says and what the patient does.
link |
So there isn't any behavior, yet in some of these people, there is still experience.
link |
You can design and build brain machine interfaces where you can see there's still experience
link |
And of course, these cases of locked in state, there's this famous book called The Diving
link |
Bell and the Butterfly, where you had an editor, a French editor, he had a stroke in the brainstem,
link |
unable to move except his vertical eyes, eye movement.
link |
He could just move his eyes up and down.
link |
And he dictated an entire book.
link |
And some people even lose this at the end.
link |
All the evidence seems to suggest that they're still in there.
link |
In this case, you have no behavior, you have consciousness.
link |
Second case is tonight, like all of us, you're going to go to sleep, close your eyes, you
link |
go to sleep, you will wake up inside your sleeping body, and you will have conscious
link |
They are different from everyday experience.
link |
You might fly, you might not be surprised that you're flying, you might meet a long
link |
dead pet, childhood dog, and you're not surprised that you're meeting them.
link |
But you have conscious experience of love, of hate, they can be very emotional.
link |
Your body during this state, typically it's REM state, sends an active signal to your
link |
motor neurons to paralyze you.
link |
It's called atonia.
link |
Because if you don't have that, like some patients, what do you do?
link |
You act out your dreams.
link |
You get, for example, REM behavioral disorder, which is bad juju to get.
link |
Third case is pure experience.
link |
So I recently had this, what some people call a mystical experience.
link |
I went to Singapore and went into a flotation tank.
link |
So this is a big tub filled with water, that's body temperature and Epsom salt.
link |
You strip completely naked, you lie inside of it, you close the lid.
link |
Complete darkness, soundproof.
link |
So very quickly, you become bodiless because you're floating and you're naked.
link |
You have no rings, no watch, no nothing.
link |
You don't feel your body anymore.
link |
There's no sound, soundless.
link |
There's no photon, sightless, timeless, because after a while, early on you actually hear
link |
your heart, but then you sort of adapt to that and then sort of the passage of time
link |
And if you train yourself, like in a meditation, not to think, early on you think a lot.
link |
It's a little bit spooky.
link |
You feel somewhat uncomfortable or you think, well, I'm going to get bored.
link |
And if you try to not to think actively, you become mindless.
link |
There you are, bodiless, timeless, you know, soundless, sightless, mindless, but you're
link |
in a conscious experience.
link |
You're not asleep.
link |
You're not asleep.
link |
You are a being of pure, you're a pure being.
link |
There isn't any function.
link |
You aren't doing any computation.
link |
You're not remembering.
link |
You're not projecting.
link |
You're not planning.
link |
Yet you are fully conscious.
link |
You're fully conscious.
link |
There's something going on there.
link |
It could be just a side effect.
link |
You mean epiphenomena.
link |
So what's the select, meaning why, what is the function of you being able to lay in this
link |
sensory free deprivation tank and still have a conscious experience?
link |
Obviously we didn't evolve with flotation tanks in our environment.
link |
I mean, so biology is notoriously bad at asking why question, telenormical question.
link |
Why do we have two eyes?
link |
Why don't we have four eyes like some teachers or three eyes or something?
link |
Well, no, there's probably, there is a function to that, but we're not very good at answering
link |
We can speculate endlessly where biology is very, or science is very good about mechanistic
link |
Why is there a charge in the universe?
link |
We find a certain universe where there are positive and negative charges.
link |
Why does quantum mechanics hold?
link |
You know, why doesn't some other theory hold?
link |
Quantum mechanics holding our universe is very unclear why.
link |
So telenormical question, why questions are difficult to answer.
link |
There's some relationship between complexity, brain processing power and consciousness.
link |
But however, in these cases, in these three examples I gave, one is an everyday experience
link |
The other one is trauma.
link |
And third one is in principle, you can, everybody can have these sort of mystical experiences.
link |
You have a dissociation of function from, of intelligence from consciousness.
link |
You caught me asking a why question.
link |
Let me ask a question that's not a why question.
link |
You're giving a talk later today on the Turing test for intelligence and consciousness, drawing
link |
lines between the two.
link |
So is there a scientific way to say there's consciousness present in this entity or not?
link |
And to anticipate your answer, cause you, you will also, there's a neurobiological answer.
link |
So we can test the human brain, but if you take a machine brain that you don't know tests
link |
for yet, how would you even begin to approach a test if there's consciousness present in
link |
That's a really good question.
link |
So let me take it in two steps.
link |
So as you point out for, for, for, for humans, let's just stick with humans.
link |
There's now a test called the Zap and Zip is a procedure where you ping the brain using
link |
transcranial magnetic stimulation.
link |
You look at the electrical reverberations essentially using EG, and then you can measure
link |
the complexity of this brain response.
link |
And you can do this in awake people, in asleep, normal people, you can do it in awake people
link |
and then anesthetize them.
link |
You can do it in patients.
link |
And it, it, it has a hundred percent accuracy that in all those cases, when you're clear,
link |
the patient or the person is either conscious or unconscious, the complexity is either high
link |
And then you can adopt these techniques to similar creatures like monkeys and dogs and,
link |
and, and mice that have very similar brains.
link |
Now of course you, you point out that may not help you because we don't have a cortex,
link |
you know, and if I send a magnetic pulse into my iPhone or my computer, it's probably going
link |
to break something.
link |
So we don't have that.
link |
So what we need ultimately, we need a theory of consciousness.
link |
We can't just rely on our intuition.
link |
Our intuition is, well, yeah, if somebody talks, they're conscious.
link |
However, then there are all these patients, children, babies don't talk, right?
link |
But we believe that, that the babies also have conscious experiences, right?
link |
And then there are all these patients I mentioned and they don't talk.
link |
When you dream, you can't talk because you're paralyzed.
link |
So what we ultimately need, we can't just rely on our intuition.
link |
We need a theory of conscience that tells us what is it about a piece of matter?
link |
What is it about a piece of highly excitable matter like the brain or like a computer that
link |
gives rise to conscious experience?
link |
We all believe, none of us believes anymore in the old story.
link |
It's a soul, right?
link |
That used to be the most common explanation that most people accept that instill a lot
link |
of people today believe, well, there's, there's God endowed only us with a special thing
link |
that animals don't have.
link |
Rene Descartes famously said, a dog, if you hit it with your carriage may yell, may cry,
link |
but it doesn't have this special thing.
link |
It doesn't have the magic, the magic soul.
link |
It doesn't have res cogitans, the soul.
link |
Now we believe that isn't the case anymore.
link |
So what is the difference between brains and, and these guys, silicon?
link |
And in particular, once their behavior matches.
link |
So if you have Siri or Alexa in 20 years from now that she can talk just as good as any
link |
possible human, what grounds do you have to say she's not conscious in particular, if
link |
she says it's of course she will, well, of course I'm conscious.
link |
You ask her how are you doing?
link |
And she'll say, well, you know, they, they'll generate some way to, of course she'll behave
link |
like a, like a person.
link |
Now there's several differences.
link |
One is, so this relates to the problem, the very hard, why is consciousness a hard problem?
link |
It's because it's subjective, right?
link |
Only I have it, for only I know I have direct experience of my own consciousness.
link |
I don't have experience in your consciousness.
link |
Now I assume as a sort of a Bayesian person who believes in probability theory and all
link |
of that, you know, I can do, I can do an abduction to the, to the best available facts.
link |
I deduce your brain is very similar to mine.
link |
If I put you in a scanner, your brain is roughly going to behave the same way as I do.
link |
If, if, if, you know, if I give you this muesli and ask you, how does it taste?
link |
You tell me things that, you know, that, that I would also say more or less, right?
link |
So I infer based on all of that, that you're conscious.
link |
Now with theory, I can't do that.
link |
So there I really need a theory that tells me what is it about, about any system, this
link |
or this, that makes it conscious.
link |
We have such a theory.
link |
So the integrated information theory, but let me first, maybe as an introduction for
link |
people who are not familiar, Descartes, can you, you talk a lot about pan, panpsychism.
link |
Can you describe what, uh, physicalism versus dualism?
link |
This you, you mentioned the soul, what, what is the history of that idea?
link |
What is the idea of panpsychism or no, the debate really, uh, out of which panpsychism
link |
can, um, emerge of, of, of, um, dualism versus, uh, physicalism or do you not see panpsychism
link |
as fitting into that?
link |
No, you can argue there's some, okay, so let's step back.
link |
So panpsychism is a very ancient belief that's been around, uh, I mean, Plato and Aristotle
link |
talks about it, uh, modern philosophers talk about it.
link |
Of course, in Buddhism, the idea is very prevalent that, I mean, there are different versions
link |
One version says everything is ensouled, everything, rocks and stones and dogs and people and forest
link |
and iPhones, all of us all, right?
link |
All matter is ensouled.
link |
That's sort of one version.
link |
Another version is that all biology, all creatures, small or large, from a single cell to a giant
link |
sequoia tree feel like something.
link |
This one I think is somewhat more realistic.
link |
Um, so the different versions, what do you mean by feel like something, have, have feelings,
link |
have some kind of, it feels like something, it may well be possible that it feels like
link |
something to be a paramecium.
link |
I think it's pretty likely it feels like something to be a bee or a mouse or a dog.
link |
So, so that you can see that's also, so panpsychism is very broad and you can, so some people,
link |
for example, Bertrand Russell, tried to advocate this, this idea, it's called Rasselian Monism,
link |
that that panpsychism is really physics viewed from the inside.
link |
So the idea is that physics is very good at describing relationship among objects like
link |
charges or like gravity, right?
link |
You know, describe the relationship between curvature and mass distribution, okay?
link |
That's the relationship among things.
link |
Physics doesn't really describe the ultimate reality itself.
link |
It's just relationship among, you know, quarks or all these other stuff from like a third
link |
And consciousness is what physics feels from the inside.
link |
So my conscious experience, it's the way the physics of my brain, particularly my cortex
link |
feels from the inside.
link |
And so if you are paramecium, you got to remember, you say paramecium, well, that's a pretty
link |
It is, but it has already a billion different molecules, probably, you know, 5,000 different
link |
proteins assembled in a highly, highly complex system that no single person, no computer
link |
system so far on this planet has ever managed to accurately simulate.
link |
Its complexity vastly escapes us.
link |
And it may well be that that little thing feels like a tiny bit.
link |
Now, it doesn't have a voice in the head like me.
link |
It doesn't have expectations.
link |
You know, it doesn't have all that complex things, but it may well feel like something.
link |
So this is really interesting.
link |
Can we draw some lines and maybe try to understand the difference between life, intelligence
link |
and consciousness?
link |
How do you see all of those?
link |
If you had to define what is a living thing, what is a conscious thing and what is an intelligent
link |
Do those intermix for you or are they totally separate?
link |
So A, that's a question that we don't have a full answer to.
link |
A lot of the stuff we're talking about today is full of mysteries and fascinating ones,
link |
For example, you can go to Aristotle, who's probably the most important scientist and
link |
philosopher who's ever lived in, certainly in Western culture.
link |
He had this idea, it's called hylomorphism.
link |
It's quite popular these days, that there are different forms of soul.
link |
The soul is really the form of something.
link |
He says, all biological creatures have a vegetative soul.
link |
That's life principle.
link |
Today, we think we understand something more than it is biochemistry and nonlinear thermodynamics.
link |
Then he said they have a sensitive soul.
link |
Only animals and humans have also a sensitive soul or a petitive soul.
link |
They can see, they can smell, and they have drives.
link |
They want to reproduce, they want to eat, et cetera.
link |
And then only humans have what he called a rational soul, okay?
link |
And that idea then made it into Christendom and then the rational soul is the one that
link |
He was very unclear.
link |
He wasn't really, I mean, different readings of Aristotle give different, whether did he
link |
believe that rational soul was immortal or not.
link |
I probably think he didn't.
link |
But then, of course, that made it through Plato into Christianity, and then this soul
link |
became immortal and then became the connection to God.
link |
So you ask me, essentially, what is our modern conception of these three, Aristotle would
link |
have called them different forms.
link |
Life, we think we know something about it, at least life on this planet, right?
link |
Although we don't understand how to originate it, but it's been difficult to rigorously
link |
You see this in modern definitions of death.
link |
In fact, right now, there's a conference ongoing, again, that tries to define legally and medically
link |
It used to be very simple.
link |
Death is you stop breathing, your heart stops beating, you're dead, totally uncontroversial.
link |
If you're unsure, you wait another 10 minutes.
link |
If the patient doesn't breathe, he's dead.
link |
Well, now we have ventilators, we have heart pacemakers, so it's much more difficult to
link |
define what death is.
link |
Typically, death is defined as the end of life and life is defined before death.
link |
Okay, so we don't have really very good definitions.
link |
Intelligence, we don't have a rigorous definition.
link |
We know something how to measure, it's called IQ or G factors, right?
link |
And we're beginning to build it in a narrow sense, right?
link |
Like go, AlphaGo and Watson and, you know, Google cars and Uber cars and all of that,
link |
it's still narrow AI and some people are thinking about artificial general intelligence.
link |
But roughly, as we said before, it's something to do with ability to learn and to adapt to
link |
But that is, as I said, also, it's radical difference from experience.
link |
And it's very unclear if you build a machine that has AGI, it's not at all a priori, it's
link |
not at all clear that this machine will have consciousness, it may or may not.
link |
So let's ask it the other way, do you think if you were to try to build an artificial
link |
general intelligence system, do you think figuring out how to build artificial consciousness
link |
would help you get to an AGI?
link |
So or put another way, do you think intelligent requires consciousness?
link |
In human, it goes hand in hand.
link |
In human, or I think in biology, consciousness, intelligence goes hand in hand, quay is illusion
link |
because the brain evolved to be highly complex, complexity via the theory integrated information
link |
theory is sort of ultimately is what is closely tied to consciousness.
link |
Ultimately it's causal power upon itself.
link |
And so in evolved systems, they go together.
link |
In artificial system, particularly in digital machines, they do not go together.
link |
And if you ask me point blank, is Alexa 20.0 in the year 2040, when she can easily pass
link |
every Turing test, is she conscious?
link |
No, even if she claims she's conscious.
link |
In fact, you could even do a more radical version of this thought experiment.
link |
You can build a computer simulation of the human brain.
link |
You know what Henry Markham in the Blue Brain Project or the Human Brain Project in Switzerland
link |
Let's grant them all the success.
link |
So in 10 years, we have this perfect simulation of the human brain.
link |
Every neuron is simulated and it has a larynx and it has motor neurons.
link |
It has a Broca's area and of course they'll talk and they'll say, hi, I just woke up.
link |
OK, even that computer simulation that can in principle map onto your brain will not
link |
Because it simulates, it's a difference between the simulated and the real.
link |
So it simulates the behavior associated with consciousness.
link |
It might be, it will, if it's done properly, will have all the intelligence that that particular
link |
person they're simulating has.
link |
But simulating intelligence is not the same as having conscious experiences.
link |
And I give you a really nice metaphor that engineers and physicists typically get.
link |
I can write down Einstein's field equation, nine or ten equations that describe the link
link |
in general relativity between curvature and mass.
link |
I can run this on my laptop to predict that the central, the black hole at the center
link |
of our galaxy will be so massive that it will twist space time around it so no light can
link |
It's a black hole.
link |
But funny, have you ever wondered why doesn't this computer simulation suck me in?
link |
It simulates gravity, but it doesn't have the causal power of gravity.
link |
That's a huge difference.
link |
So it's a difference between the real and the simulator, just like it doesn't get wet
link |
inside a computer when the computer runs code that simulates a weather storm.
link |
And so in order to have, to have artificial consciousness, you have to give it the same
link |
causal power as the human brain.
link |
You have to build so called a neuromorphic machine that has hardware that is very similar
link |
to the human brain, not a digital clocked phenomenon computer.
link |
So that's, just to clarify though, you think that consciousness is not required to create
link |
human level intelligence.
link |
It seems to accompany in the human brain, but for machine not.
link |
So maybe just because this is AGI, let's dig in a little bit about what we mean by intelligence.
link |
So one thing is the G factor, these kind of IQ tests of intelligence.
link |
But I think if you, maybe another way to say, so in 2040, 2050, people will have Siri that
link |
is just really impressive.
link |
Do you think people will say Siri is intelligent?
link |
Intelligence is this amorphous thing.
link |
So to be intelligent, it seems like you have to have some kind of connections with other
link |
human beings in a sense that you have to impress them with your intelligence.
link |
And there feels, you have to somehow operate in this world full of humans.
link |
And for that, there feels like there has to be something like consciousness.
link |
So you think you can have just the world's best natural NLP system, natural language
link |
understanding generation, and that will be, that will get us happy and say, you know what,
link |
we've created an AGI.
link |
I don't know happy, but yes, I do believe we can get what we call high level functional
link |
intelligence, particular sort of the G, you know, this fluid like intelligence that we
link |
cherish, particularly at a place like MIT, right, in machines.
link |
I see a priori no reasons, and I see a lot of reason to believe it's going to happen
link |
very, you know, over the next 50 years or 30 years.
link |
So for beneficial AI, for creating an AI system that's, so you mentioned ethics, that is exceptionally
link |
intelligent but also does not do, does, you know, aligns its values with our values as
link |
Do you think then it needs consciousness?
link |
Yes, I think that that is a very good argument that if we're concerned about AI and the threat
link |
of AI, a la Nick Bostrom, existentialist threat, I think having an intelligence that has empathy,
link |
right, why do we find abusing a dog, why do most of us find that abhorrent, abusing any
link |
Why do we find that abhorrent because we have this thing called empathy, which if you look
link |
at the Greek really means feeling with, I feel a path of empathy, I have feeling with
link |
I see somebody else suffer that isn't even my conspecific, it's not a person, it's not
link |
my wife or my kids, it's a dog, but I feel naturally most of us, not all of us, most
link |
of us will feel emphatic.
link |
And so it may well be in the long term interest of survival of homo sapiens sapiens that if
link |
we do build AGI and it really becomes very powerful that it has an emphatic response
link |
and doesn't just exterminate humanity.
link |
So as part of the full conscious experience to create a consciousness, artificial or in
link |
our human consciousness, do you think fear, maybe we're going to get into the earlier
link |
days with Nietzsche and so on, but do you think fear and suffering are essential to
link |
have consciousness?
link |
Do you have to have the full range of experience to have a system that has experience or can
link |
you have a system that only has very particular kinds of very positive experiences?
link |
Look you can have in principle, people have done this in the rat where you implant an
link |
electrode in the hypothalamus, the pleasure center of the rat and the rat stimulates itself
link |
above and beyond anything else.
link |
It doesn't care about food or natural sex or drink anymore, it just stimulates itself
link |
because it's such a pleasurable feeling.
link |
I guess it's like an orgasm just you have all day long.
link |
And so a priori I see no reason why you need a great variety.
link |
Now clearly to survive that wouldn't work, right?
link |
But if I'd engineered artificially, I don't think you need a great variety of conscious
link |
You could have just pleasure or just fear.
link |
It might be a terrible existence, but I think that's possible at least on conceptual logical
link |
Because any real creature whether artificially engineered, you want to give it fear, the
link |
fear of extinction that we all have.
link |
And you also want to give it positive repetitive states, states that you want the machine encouraged
link |
to do because they give the machine positive feedback.
link |
So you mentioned panpsychism, to jump back a little bit, everything having some kind
link |
of mental property.
link |
How do you go from there to something like human consciousness?
link |
So everything having some elements of consciousness, is there something special about human consciousness?
link |
So it's not everything.
link |
Like a spoon, the form of panpsychism I think about doesn't ascribe consciousness to anything
link |
like this, the spoon on my liver.
link |
However, the theory, the integrated information theory does say that the system, even one
link |
that looks from the outside relatively simple, at least if they have this internal causal
link |
power, it does feel like something.
link |
The theory a priori doesn't say anything what's special about human.
link |
Biologically we know the one thing that's special about human is we speak and we have
link |
an overblown sense of our own importance.
link |
We believe we're exceptional and we're just God's gift to the universe.
link |
But behaviorally the main thing that we have, we can plan over the long term, we have language
link |
and that gives us an enormous amount of power and that's why we are the current dominant
link |
species on the planet.
link |
So you mentioned God, you grew up a devout Roman Catholic family, so with consciousness
link |
you're sort of exploring some really deeply fundamental human things that religion also
link |
Where does religion fit into your thinking about consciousness?
link |
You've grown throughout your life and changed your views on religion as far as I understand.
link |
Yeah, I mean I'm now much closer to, I'm not a Roman Catholic anymore, I don't believe
link |
there's sort of this God, the God I was educated to believe in, sits somewhere in the fullness
link |
of time, I'll be united in some sort of everlasting bliss, I just don't see any evidence for that.
link |
Look, the world, the night is large and full of wonders, there are many things that I don't
link |
understand, I think many things that we as a cult, look we don't even understand more
link |
than 4% of all the universe, dark matter, dark energy, we have no idea what it is, maybe
link |
it's lost socks, what do I know?
link |
So all I can tell you is it's sort of my current religious or spiritual sentiment is much closer
link |
to some form of Buddhism, without the reincarnation unfortunately, there's no evidence for it
link |
than reincarnation.
link |
So can you describe the way Buddhism sees the world a little bit?
link |
Well so they talk about, so when I spent several meetings with the Dalai Lama and what always
link |
impressed me about him, he really, unlike for example let's say the Pope or some Cardinal,
link |
he always emphasized minimizing the suffering of all creatures.
link |
So they have this, from the early beginning they look at suffering in all creatures, not
link |
just in people, but in everybody, this universal and of course by degrees, an animal in general
link |
is less capable of suffering than a well developed, normally developed human and they think consciousness
link |
pervades in this universe and they have these techniques, you can think of them like mindfulness
link |
etc. and meditation that tries to access what they claim of this more fundamental aspect
link |
I'm not sure it's more fundamental, I think about it, there's the physical and then there's
link |
this inside view, consciousness and those are the two aspects that's the only thing
link |
I have access to in my life and you've got to remember my conscious experience and your
link |
conscious experience comes prior to anything you know about physics, comes prior to knowledge
link |
about the universe and atoms and super strings and molecules and all of that.
link |
The only thing you directly are acquainted with is this world that's populated with things
link |
in images and sounds in your head and touches and all of that.
link |
I actually have a question, so it sounds like you kind of have a rich life, you talk about
link |
rock climbing and it seems like you really love literature and consciousness is all about
link |
experiencing things, so do you think that has helped your research on this topic?
link |
Yes, particularly if you think about it, the various states, so for example when you do
link |
rock climbing or now I do rowing, crew rowing and a bike every day, you can get into this
link |
thing called the zone and I've always wanted about it, particularly with respect to consciousness
link |
because it's a strangely addictive state.
link |
Once people have it once, they want to keep on going back to it and you wonder what is
link |
it so addicting about it and I think it's the experience of almost close to pure experience
link |
because in this zone, you're not conscious of inner voice anymore, there's always inner
link |
voice nagging you, you have to do this, you have to do that, you have to pay your taxes,
link |
you have to fight with your ex and all of those things, they're always there.
link |
But when you're in the zone, all of that is gone and you're just in this wonderful state
link |
where you're fully out in the world, you're climbing or you're rowing or biking or doing
link |
soccer or whatever you're doing and sort of consciousness is this, you're all action or
link |
in this case of pure experience, you're not action at all but in both cases, you experience
link |
some aspect of conscious, you touch some basic part of conscious existence that is so basic
link |
and so deeply satisfying.
link |
You I think you touch the root of being, that's really what you're touching there, you're
link |
getting close to the root of being and that's very different from intelligence.
link |
So what do you think about the simulation hypothesis, simulation theory, the idea that
link |
we all live in a computer simulation?
link |
Rapture for nerds.
link |
Rapture for nerds.
link |
I think it's as likely as the hypothesis had engaged hundreds of scholars for many centuries,
link |
are we all just existing in the mind of God?
link |
And this is just a modern version of it, it's equally plausible.
link |
People love talking about these sort of things, I know they're book written about this simulation
link |
hypothesis, if that's what people want to do, that's fine, it seems rather esoteric,
link |
it's never testable.
link |
But it's not useful for you to think of in those terms, so maybe connecting to the questions
link |
of free will which you've talked about, I vaguely remember you saying that the idea
link |
that there's no free will, it makes you very uncomfortable.
link |
So what do you think about free will from a physics perspective, from a conscious perspective,
link |
what does it all fit?
link |
Okay, so from the physics perspective, leaving aside quantum mechanics, we believe we live
link |
in a fully deterministic world, right?
link |
But then comes of course quantum mechanics, so now we know that certain things are in
link |
principle not predictable, which as you said I prefer, because the idea that the initial
link |
condition of the universe and then everything else, we're just acting out the initial condition
link |
of the universe, that doesn't…
link |
It's not a romantic notion.
link |
Now when it comes to consciousness, I think we do have certain freedom.
link |
We are much more constrained by physics of course and by our past and by our own conscious
link |
desires and what our parents told us and what our environment tells us.
link |
We all know that, right?
link |
There's hundreds of experiments that show how we can be influenced.
link |
But finally in the final analysis, when you make a life – and I'm talking really about
link |
critical decision where you really think, should I marry, should I go to this school
link |
or that school, should I take this job or that job, should I cheat on my taxes or not?
link |
These are things where you really deliberate and I think under those conditions, you are
link |
as free as you can be.
link |
When you bring your entire being, your entire conscious being to that question and try to
link |
analyze it under all the various conditions, then you make a decision, you are as free
link |
as you can ever be.
link |
That is I think what free will is.
link |
It's not a will that's totally free to do anything it wants.
link |
That's not possible.
link |
So as Jack mentioned, you actually write a blog about books you've read, amazing books
link |
from, I'm Russian, from Bulgakov, Neil Gaiman, Carl Sagan, Murakami.
link |
So what is a book that early in your life transformed the way you saw the world, something
link |
that changed your life?
link |
Nietzsche I guess did.
link |
That's Brooks R. Truster because he talks about some of these problems.
link |
He was one of the first discoverer of the unconscious.
link |
This is a little bit before Freud when he was in the air.
link |
He makes all these claims that people sort of under the guise or under the mass of charity
link |
actually are very noncharitable.
link |
So he is sort of really the first discoverer of the great land of the unconscious and that
link |
And what do you think about the unconscious, what do you think about Freud, what do you
link |
think about these ideas?
link |
Just like dark matter in the universe, what's over there in that unconscious?
link |
I mean much more than we think.
link |
This is what a lot of last 100 years of research has shown.
link |
So I think he was a genius, misguided towards the end, but he started out as a neuroscientist.
link |
He contributed, he did the studies on the lamprey, he contributed himself to the neuron
link |
hypothesis, the idea that there are discrete units that we call nerve cells now.
link |
And then he wrote about the unconscious and I think it's true, there's lots of stuff happening.
link |
You feel this particular when you're in a relationship and it breaks asunder, right?
link |
And then you have this terrible, you can have love and hate and lust and anger and all of
link |
And when you try to analyze yourself, why am I so upset?
link |
It's very, very difficult to penetrate to those basements, those caverns in your mind
link |
because the prying eyes of conscious doesn't have access to those, but they're there in
link |
the amygdala or lots of other places.
link |
They make you upset or angry or sad or depressed and it's very difficult to try to actually
link |
uncover the reason.
link |
You can go to a shrink, you can talk with your friend endlessly, you construct finally
link |
a story why this happened, why you love her or don't love her or whatever, but you don't
link |
really know whether that actually happened because you simply don't have access to those
link |
parts of the brain and they're very powerful.
link |
Do you think that's a feature or a bug of our brain?
link |
The fact that we have this deep, difficult to dive into subconscious?
link |
I think it's a feature because otherwise, look, we are like any other brain or nervous
link |
system or computer, we are severely band limited.
link |
If everything I do, every emotion I feel, every eye movements I make, if all of that
link |
had to be under the control of consciousness, I wouldn't be here.
link |
What you do early on, your brain, you have to be conscious when you learn things like
link |
typing or like riding on a bike, but then what you do, you train up routes, I think
link |
that involve basal ganglia and striatum.
link |
You train up different parts of your brain and then once you do it automatically like
link |
typing, you can show you do it much faster without even thinking about it because you've
link |
got these highly specialized, what Frans Krik and I call zombie agents, they're taking care
link |
of that while your consciousness can sort of worry about the abstract sense of the text
link |
you want to write.
link |
I think that's true for many, many things.
link |
But for the things like all the fights you had with an ex girlfriend, things that you
link |
would think are not useful to still linger somewhere in the subconscious.
link |
So that seems like a bug that it would stick to there.
link |
You think it would be better if you can analyze it and then get it out of the system.
link |
Better to get it out of the system or just forget it ever happened.
link |
That seems a very buggy kind of.
link |
Well yeah, in general we don't have, and that's probably functional, we don't have an ability
link |
unless it's extreme, there are cases, clinical dissociations, right?
link |
When people are heavily abused, when they completely repress the memory, but that doesn't
link |
happen in normal people.
link |
We don't have an ability to remove traumatic memories and of course we suffer from that.
link |
On the other hand, probably if you had the ability to constantly wipe your memory, you'd
link |
probably do it to an extent that isn't useful to you.
link |
So yeah, it's a good question to balance.
link |
So on the books, as Jack mentioned, correct me if I'm wrong, but broadly speaking, academia
link |
and the different scientific disciplines, certainly in engineering, reading literature
link |
seems to be a rare pursuit.
link |
So I'm wrong on this, but that's in my experience, most people read much more technical text
link |
and do not sort of escape or seek truth in literature.
link |
It seems like you do.
link |
So what do you think is the value, what do you think literature adds to the pursuit of
link |
Do you think it's good, it's useful for everybody?
link |
Gives you access to a much wider array of human experiences.
link |
How valuable do you think it is?
link |
Well if you want to understand human nature and nature in general, then I think you have
link |
to better understand a wide variety of experiences, not just sitting in a lab staring at a screen
link |
and having a face flashed onto you for a hundred milliseconds and pushing a button.
link |
That's what I used to do, that's what most psychologists do.
link |
There's nothing wrong with that, but you need to consider lots of other strange states.
link |
And literature is a shortcut for this.
link |
Well yeah, because literature, that's what literature is all about, all sorts of interesting
link |
experiences that people have, the contingency of it, the fact that women experience the
link |
world different, black people experience the world different.
link |
The one way to experience that is reading all these different literature and try to
link |
You see, everything is so relative.
link |
You read a book 300 years ago, they thought about certain problems very, very differently
link |
We today, like any culture, think we know it all.
link |
That's common to every culture.
link |
Every culture believes at its heyday they know it all.
link |
And then you realize, well, there's other ways of viewing the universe and some of them
link |
may have lots of things in their favor.
link |
So this is a question I wanted to ask about time scale or scale in general.
link |
When you, with IIT or in general, try to think about consciousness, try to think about these
link |
ideas, we kind of naturally think in human time scales, and also entities that are sized
link |
Do you think of things that are much larger and much smaller as containing consciousness?
link |
And do you think of things that take, you know, eons to operate in their conscious cause
link |
That's a very good question.
link |
So I think a lot about small creatures because experimentally, you know, a lot of people
link |
work on flies and bees, right?
link |
So most people just think they are automata, they're just bugs for heaven's sake, right?
link |
But if you look at their behavior, like bees, they can recognize individual humans.
link |
They have this very complicated way to communicate.
link |
If you've ever been involved or you know your parents when they bought a house, what sort
link |
of agonizing decision that is.
link |
And bees have to do that once a year, right, when they swarm in the spring.
link |
And then they have this very elaborate way, they have free and scouts, they go to the
link |
individual sites, they come back, they have this power, this dance, literally, where they
link |
dance for several days, they try to recruit other deets, this very complicated decision
link |
rate, when they finally, once they make a decision, the entire swarm, the scouts warm
link |
up the entire swarm and then go to one location.
link |
They don't go to 50 locations, they go to one location that the scouts have agreed upon
link |
If we look at the circuit complexity, it's 10 times more denser than anything we have
link |
Now they only have a million neurons, but the neurons are amazingly complex.
link |
Complex behavior, very complicated circuitry, so there's no question they experience something,
link |
their life is very different, they're tiny, they only live, you know, for, well, workers
link |
live maybe for two months.
link |
So I think, and IIT tells you this, in principle, the substrate of consciousness is the substrate
link |
that maximizes the cause effect power over all possible spatial temporal grains.
link |
So when I think about, for example, do you know the science fiction story, The Black
link |
Okay, it's a classic by Fred Hoyle, the astronomer.
link |
He has this cloud intervening between the earth and the sun and leading to some sort
link |
of, to global cooling, this is written in the 50s.
link |
It turns out you can, using the radio dish, they communicate with actually an entity,
link |
it's actually an intelligent entity, and they sort of, they convince it to move away.
link |
So here you have a radical different entity, and in principle, IIT says, well, you can
link |
measure the integrated information, in principle at least, and yes, if the maximum of that
link |
occurs at a time scale of months, rather than in assets for a fraction of a second, yes,
link |
then they would experience life where each moment is a month rather than, or microsecond,
link |
right, rather than a fraction of a second in the human case.
link |
And so there may be forms of consciousness that we simply don't recognize for what they
link |
are because they are so radical different from anything you and I are used to.
link |
Again, that's why it's good to read or to watch science fiction movies, well, to think
link |
Do you know Stanislav Lem, this Polish science fiction writer, he wrote Solaris and was turned
link |
into a Hollywood movie?
link |
His best novel is in the 60s, a very engineer, he's an engineer in background.
link |
His most interesting novel is called The Victorious, where human civilization, they have this
link |
mission to this planet and everything is destroyed and they discover machines, humans got killed
link |
and then these machines took over and there was this machine evolution, Darwinian evolution,
link |
he talks about this very vividly.
link |
And finally, the dominant machine intelligence organism that survived were gigantic clouds
link |
of little hexagonal universal cellular automata.
link |
This was written in the 60s, so typically they're all lying on the ground individual
link |
by themselves, but in times of crisis, they can communicate, they assemble into gigantic
link |
nets into clouds of trillions of these particles and then they become hyper intelligent and
link |
they can beat anything that humans can throw at it.
link |
It's very beautiful and compelling where you have an intelligence where finally the humans
link |
leave the planet, they're simply unable to understand and comprehend this creature.
link |
They can say, well, either we can nuke the entire planet and destroy it or we just have
link |
to leave because fundamentally it's an alien, it's so alien from us and our ideas that we
link |
cannot communicate with them.
link |
Yeah, actually in conversation, so you're talking to us, Steven Wolf from Brought Up
link |
is that there could be ideas that you already have these artificial general intelligence
link |
like super smart or maybe conscious beings in the cellular automata, we just don't know
link |
how to talk to them.
link |
So it's the language of communication, but you don't know what to do with it.
link |
So that's one sort of view is consciousness is only something you can measure.
link |
So it's not conscious if you can't measure it.
link |
So you're making an ontological and an epistemic statement.
link |
One is it's just like seeing the multiverses, that might be true, but I can't communicate
link |
I can't have any knowledge of them.
link |
That's an epistemic argument.
link |
So those are two different things.
link |
So it may well be possible.
link |
Look, in another case that's happening right now, people are building these mini organoids.
link |
Do you know what this is?
link |
So you can take stem cells from under your arm, put it in a dish, add four transcription
link |
factors and then you can induce them to grow into large, well, large, they're a few millimeters.
link |
They're like a half a million neurons that look like nerve cells in a dish called mini
link |
organoids at Harvard, at Stanford, everywhere they're building them.
link |
It may well be possible that they're beginning to feel like something, but we can't really
link |
communicate with them right now.
link |
So people are beginning to think about the ethics of this.
link |
So yes, he may be perfectly right, but it's one question, are they conscious or not?
link |
It's a totally separate question.
link |
Those are two different things.
link |
If you could give advice to a young researcher, sort of dreaming of understanding or creating
link |
human level intelligence or consciousness, what would you say?
link |
Just follow your dreams.
link |
No, I mean, I suppose with discipline, what is the pursuit that they should take on?
link |
Is it neuroscience?
link |
Is it computational cognitive science?
link |
Is it computer science or robotics?
link |
No, in a sense that, okay, so the only known system that have high level of intelligence
link |
So if you wanted to build it, it's probably good to continue to study closely what humans
link |
So cognitive neuroscience, you know, somewhere between cognitive neuroscience on the one hand
link |
and some philosophy of mind and then AI, AI computer science.
link |
You can look at all the original ideas in your network, they all came from neuroscience,
link |
Reinforce whether it's Snarky, Minsky building is Snarky or whether it's, you know, the early
link |
Hubel and Wiesel experiments at Harvard that then gave rise to networks and then multi
link |
So it may well be possible, in fact, some people argue that to make the next big step
link |
in AI once we realize the limits of deep convolutional networks, they can do certain things, but
link |
they can't really understand.
link |
They don't, they can't really, I can't really show them one image.
link |
I can show you a single image of somebody, a pickpocket who steals a wallet from a purse.
link |
You immediately know that's a pickpocket.
link |
Now computer system would just say, well, it's a man, it's a woman, it's a purse, right?
link |
Unless you train this machine on showing it a hundred thousand pickpockets, right?
link |
So it doesn't have this easy understanding that you have, right?
link |
So some people make the argument in order to go to the next step or you really want
link |
to build machines that understand in a way you and I, we have to go to psychology.
link |
We need to understand how we do it and how our brains enable us to do it.
link |
And so therefore being on the cusp, it's also so exciting to try to understand better our
link |
nature and then to build, to take some of those inside and build them.
link |
So I think the most exciting thing is somewhere in the interface between cognitive science,
link |
neuroscience, AI, computer science and philosophy of mind.
link |
I'd say if there is from the machine learning, from our, from the computer science, computer
link |
vision perspective, many of the researchers kind of ignore the way the human brain works
link |
or even psychology or literature or studying the brain, I would hope Josh Tenenbaum talks
link |
about bringing that in more and more.
link |
And that's, yeah, so you've worked on some amazing stuff throughout your life.
link |
What's the thing that you're really excited about?
link |
What's the mystery that you would love to uncover in the near term beyond, beyond all
link |
the mysteries that you're already surrounded by?
link |
Well, so there's a structure called the claustrum.
link |
This is a structure, it's underneath our cortex, it's yay big.
link |
You have one on the left, on the right, underneath this, underneath the insula, it's very thin,
link |
it's like one millimeter, it's embedded in, in wiring, in white matter, so it's very difficult
link |
And it has, it has connection to every cortical region.
link |
And Francis Crick, the last paper he ever wrote, he dictated corrections the day he
link |
died in hospital on this paper.
link |
You know, we hypothesize, well, because it has this unique anatomy, it gets input from
link |
every cortical area and projects back to every, every cortical area.
link |
That the function of this structure is similar, it's just a metaphor to the role of a conductor
link |
in a symphony orchestra.
link |
You have all the different cortical players.
link |
You have some that do motion, some that do theory of mind, some that infer social interaction
link |
and color and hearing and all the different modules in cortex.
link |
But of course, what consciousness is, consciousness puts it all together into one package, right?
link |
The binding problem, all of that.
link |
And this is really the function because it has relatively few neurons compared to cortex,
link |
but it talks, it receives input from all of them and it projects back to all of them.
link |
And so we're testing that right now.
link |
We've got this beautiful neuronal reconstruction in the mouse called crown of thorns, crown
link |
of thorns neurons that are in the claustrum that have the most widespread connection of
link |
any neuron I've ever seen.
link |
They're very, you have individual neurons that sit in the claustrum tiny, but then they
link |
have this single neuron, they have this huge axonal tree that cover both ipsy and contralateral
link |
cortex and trying to turn using, you know, fancy tools like optogenetics, trying to turn
link |
those neurons on or off and study it, what happens in the, in the mouse.
link |
So this thing is perhaps where the parts become the whole.
link |
Perhaps it's one of the structures, it's a very good way of putting it, where the individual
link |
parts turn into the whole of the whole of the conscious experience.
link |
Well, with that, thank you very much for being here today.
link |
Thank you very much.
link |
Thank you very much.
link |
All right, thank you very much.