[MUSIC PLAYING]
NICK CHATER: Thank you
very much, [INAUDIBLE],,
and thank you very much,
everyone, for coming along.
It's a great pleasure
to have the opportunity
to talk to Google, and
it's a great opportunity
to have a chance to share some
ideas and to get your feedback.
So I'm going to attempt to
encapsulate my talk fairly
briefly.
I will try to be
concise enough that you
have lots of opportunity
to ask questions.
And also, if you feel
you want to object--
your sense of outrage
halfway through
and you want to object
as I'm going along,
that's absolutely fine.
Let's make it interactive.
So the mind is flat.
That sounds like a very
radical claim, and it is.
But what is it?
What is this claim?
And the intuition will
become clear as we go along,
but the thing I
want to kick against
is, essentially,
in the subtitle,
the illusion of mental depth.
So the idea I think
a lot of us have
is that there is this
flow of thoughts,
the conscious experience
that I'm experiencing now,
that you're experiencing now.
And that is just
one tiny flicker
on the surface of a
great stream, or maybe
a vast river of their
thoughts, most of which
are hidden mysteriously, but
nonetheless flowing out to sea.
And this idea, that what we
consciously experience is just
a tiny fraction of all the other
stuff that our brain is doing,
which is also mysteriously
hidden thought,
is a very, very
powerful intuition.
Now, it's a recent intuition.
So if you went back
100 years, or well,
that's 150 years
pre-Freud, nobody really
had this intuition.
The idea then was the
mind is that thing which
you can experience.
So the idea that there
could be thoughts
that somehow you
can't experience
would seem inherently
a bit crazy.
But since Freud, and
indeed since we've
understood the
brain a lot better,
it becomes much more natural
to think, well, hang on,
the brain's doing all kinds
of complicated things.
Perhaps my x behavior
can be explained
by all sorts of
mysterious machinery,
mysterious mental activity,
that I'm not aware of.
Now, I think, of course, the
brain is doing lots of things,
which I'm not aware of,
but they're not false.
There's something very
special, very particular,
about the stream
of thoughts, which
makes them very different from
other things our brains are
doing.
And I want to suggest to you
that your natural pre-theoretic
thought-- that no, actually, my
mind is this flow, this stream,
of conscious experience--
that is, in fact, correct.
Now, if that's right, and
we will see a lot more--
you'll see some reason
to believe this.
It's not just a lot of coming
completely out of nowhere.
We'll see some reasons why you
might want to believe this.
If it's right-- that, in fact,
you can only think one thought
at a time and that's the story,
one thought at once, no more--
then we somehow seem to
give a good impression
that our thoughts are highly
coherent and integrated.
So it's not the case that I
just spew out random sentences,
and here's another
one and here's
another, in a way that
seems totally uncoordinated.
It's almost as if there was
a plan behind these sentence.
It's almost as if underneath,
there's some sort of theory,
or sort of grand set of
principles, on which I'm
drawing, from which these
little individual snippets are
issuing.
But what I think that is telling
us is we are remarkably good
improvisers.
It's not the case, in fact,
that there's a script inside me,
or a set of principles which
are generating the script which
I'm just playing out.
In fact, I'm improvising now
in telling you my thesis, just
as you're always
improvising whenever
you are having a
conversation with anybody
or doing any social interaction.
And yet, of course, we're
very, very consummate,
very good improvisers.
So imagine, for example, the
case of improvisational acting.
You're told, now play
the role of somebody
in their particular situation,
fit their age, so off you go.
And you start to think, well,
I seem to be saying this.
I seem to be saying that.
Oh, someone's responded.
This is the kind of thing
we all do in drama classes.
A little interchange occurs,
a story might start to emerge.
Obviously, in that case, we
know that the story did not
preexist.
The character we're now creating
did not preexist either.
The suggestion I have
for you is that's what
you're doing all the time.
There's not the case that
you're different from when
you are behaving normally to
what you're doing when you're
doing improvisational acting,
except the part you're playing
is your own part.
Still, leave those
thoughts aside, though.
Let's look at some examples
and some illustrations,
and we'll come back
to the big picture.
Here is a fun
illustration, which
is fun, irrespective of
anything else I'm going to say.
If you take nothing
else away, this
is just a wonderful,
wonderful, strange illusion.
This is the 12 dots illusion.
This is invented by a French
vision scientist, Jack Ninio.
And you'll notice there
are 12 dots, 12 black dots,
on the screen.
Can you see them all?
See they're all nice and clear?
They're perfectly
large enough to see.
I don't know if any of
you are having trouble
seeing all of them at once.
You see them come
and go, don't they?
There's no trickery.
This is the Power Point
of the normal kind.
The dots are all visible,
perfectly large enough to see.
If I turn the grid away, you can
see 12 dots, plain as the nose
on your face.
Now, when I put that
grid in that location--
if I move the grid to the
side, the 12 dots would pop out
again--
if they're in that
location, strangely, they
keep popping in and
out of existence.
So I find, for
example, I'm seeing
a row of four, oh, and now
a different row of four.
Now I can see two.
Oh, hang on.
Yup, the bottom row's appeared.
There was just
three for a minute
and now a fourth one appeared.
It's all very odd.
What's going on?
Well, the first
thing that's going on
is this should give you a sense
of the constructive nature
of perception.
If you have a secret belief that
your perceptual experience is
just a reflection
of the world, then
this should make you doubt that,
because the world is stable
here.
But your perception
is not stable.
Also, think about the
chunks you're seeing.
Sometimes you see just
one dot, sometimes two.
Then there'll be a row.
They're not just peeking up
and popping up at random.
You're finding cohesive units.
Things like rows, things like
pairs, things like single dots.
What you're not finding is, oh,
I saw one dot on the top right,
and oh, another one
at the bottom left.
No, you don't see that.
These are organized, and only
one organization at once.
So what you will not
find is you will not
find yourself thinking,
oh, I see a diagonal bar
and a horizontal bar at once.
You cannot see that.
If you see one bar, the
other stuff is just gone.
You can't see anything else.
I'm not sure I
can see a diagram.
Oh, hang on.
I got six at once.
I got a little
domino-shaped chunk.
I don't know if you did.
You keep looking, you keep
getting different stuff.
But it's always organized.
So what that's
implying is that what
your perception, your conscious
experience, is tracking
is the organizations you're
imposing on the world.
It's not just the raw stimulus,
it's the organizations.
And we can only impose
one organization at once,
and the brain is continually
looking for organizations,
grabbing them, and then
saying, I've got one now.
I throw it away.
Let me find a new one.
I throw that one away.
I find a new one.
Your brain is continually
re-processing the same material
and reorganizing it.
So as I look at you now,
I'm doing the same thing,
but it's not so obvious to me.
So I have a sense of seeing
your faces before me.
I have a sense that there
are many, many people.
And you're all visible
in perfect detail,
in perfect color.
But that can't be right, can it?
Because you all know, from
elementary school biology,
that, actually, almost
all of your color vision
is just in a tiny, tiny
little window about this big,
as I look through the world.
That's where almost all
the color is, in the back
of my retina.
There's a little bits of
color outside, but not much.
And, in fact, we know
that because there
are different cells
for picking up color,
as I'm sure you all
know, than there are,
for example, detecting
change and detecting just
black and white image intensity,
differences, and so on.
So most of the color
that you can see
is in this little window, and
yet, the world looks colorful.
Also, as you know
perfectly well,
you can only see
detail on the fovea.
It's this little area where
you're looking exactly.
So as I look around the world
through my little, as it were,
telescope, where I'm
looking is in real detail,
but everywhere else isn't.
But that's odd because
I seem to see you
all of you in full color and
in full detail all the time,
and that is an illusion.
What's actually
going on is very much
what you see here is
I'm finding one face,
then I'm finding another
face, then another face,
but I can't recognize
two faces at once.
And, in fact, there
are lovely experiments,
which I'm going to
show you, but there
are lovely experiments where
you look at where someone's
pointing their eye.
What we'll do is we'll look at
a case with reading in a minute,
not faces.
You look at where someone's
pointing their eye
in a crowd of faces, and
wherever they're looking,
there's a face.
All the other faces
are somehow scrambled.
They've just been mashed up by
some sort of image processing.
You don't see anything strange,
you just think, oh yeah,
everyone's there,
perfectly as normal,
as you scan what might
be a school photograph.
Everything is scrambled
faces, except the one
you're looking at.
That's fine.
You don't notice anything.
So I have the feeling I'm
seeing you all in perfect detail
and I'm recognizing
all these faces,
and I recognize and
see the people who
are looking entranced,
and a little skeptical.
But no, that's not true at all.
Here's something else, which
is giving you the strong sense,
I think, that the brain is much
more serial, much more one step
at a time than you might think.
You find one organization
in the world,
you impose the organization,
and then you reach the next one.
Then you reach the next one.
But you don't do
them all at once.
You have the sense that
you're doing them all at once,
but that's an illusion.
So this is a lovely piece
of experimental work
done by two psychologists of
attention, Huang and Pashler.
They've done loads
of great stuff.
This is just one example.
Their big thing is that you can
only see one color at a time.
Now, you might think, hang on.
That's just got to be crazy.
I mean, look, here
are some grids.
I mean, I can see
more than one color.
I can see the red, green, and
yellow, and blue, can't I?
Well, at first,
before we do the talk
through this little
stimulus, and the way
they talked about it,
just note the following.
If I asked you how many colors
are there on that screen,
it's quite a hard question.
Four is the answer,
but you have to count.
You don't just say
immediately, oh yeah, four.
If I had four dots
on the screen,
you could straightaway
tell me, four dots,
because you're able to
process dots in parallel.
So four dots, four
elephants, four fish.
You can say straightaway four.
Actually, five, you can't.
5, 6, 7, you do start
to have to count.
But 1, 2, 3, or 4, you can
process them in parallel.
But colors are not like that.
When you see a color, you've
got to think, OK, blue,
I've got blue.
Now, red, oh yes.
And now yellow.
And you've got to count
them one after the other.
And it looks like, according
to their theory, what
you're doing is when
you're focusing on red,
yellow has gone.
Green has gone.
There's a general
sense of colored stuff,
everything else is
colored and varied,
but the only natural
color you are seeing
is red or yellow or green.
Now, let me try and convince you
a rather bit more persuasively.
We're taking you through
one of the demonstrations.
So here, we have
these little grids.
And you'll notice
that in this grid,
the grids are, in
fact, matching.
They are the same grid.
Notice how unobvious that is.
That is really not obvious.
You have to just go through and
think, oh, two green squares,
two red squares.
Oh, two green squares,
two red squares.
You just have to go through
step by step and check.
Here's something neat.
Why don't you just think about
the reds and check those?
Oh, you can do that, can't you?
You can suddenly see, oh yeah,
reds are this funny shape here.
There it is.
Yeah, the reds are the same, OK.
And now what about the yellows?
Oh yeah, the yellows
are the same.
And what about the blues?
Oh yeah, the blues are the same.
Because every time
I give you a color,
you suddenly see a
pattern in that color.
And you can compare.
You can see that
pattern all at once.
You can see all the green.
You can see all the yellows.
You can see all blues.
And you can see
they are the same.
But you can't see
more than one color.
So if I say, OK, what shape
is created by the greens?
Easy.
The greens are this shape.
The yellows are that shape.
If I say, oh, just what shape
would be created by the greens
and yellows put together?
No idea.
Impossible.
One color at a time.
So the thought here is that when
you get people to do this task,
the best way to do
it, and the only way
they can do it quickly, is
just to look at each color one
after the other.
Similarly with symmetry,
same trick, of course.
Similarly with mental rotations.
So let's just do symmetry.
So here we're saying, oh,
these two things are the same.
You can't process color in
parallel so you don't know.
But what you can do is think,
well, the yellows are the same.
Oh, and blues are the same, and
I'm doing it as they say it.
It's the reds, yeah,
they're the same.
And oh yes, the
greens are the same.
Well, they have mirrors.
I can do that, but I
can't do them all at once.
So let's have another
look at something
and go back to something we
were talking about a moment ago.
I mentioned that-- this is
going back to the surreality
of vision, not color anymore--
I mentioned that you can
have an experiment where
we look at, say, a
school photograph
and we mash all the faces except
the one you're looking at,
and you notice nothing unusual.
This is the original
demonstration of that type
of phenomenon, which
was done, actually,
in the mid-'70s by Keith
Rayner, a famous psychologist
of reading.
And this experiment
became possible
because it became possible
to track people's eyes
and create chains
in computer display
instantly, or quite instantly,
but instantly enough
as they move their
eyes across the screen.
So this is the reading
version of a few experiments
I mentioned with faces.
So what we have is a sentence,
which in this case is,
"It's remarkable how
little we actually see
at any instant, even though."
And here's your eye.
And when your eye is here,
we create a little window
of 15 letters, 10 roughly to
the right, five to the left.
If you're reading a
language, like Hebrew,
which goes the other
way, then you'd
have the window larger
in the other direction
towards the left,
because the brain
is slightly more
interested in previewing
than looking backwards.
So what you do is you just
change all the other letters
to Xs and you just allow a
little window of lucidity here.
Now, as soon as you
move your eye to here,
suddenly the window
of lucidity is moved.
And again and again
and again and again.
And you could read the
sentence quite happily.
You don't realize
anything funny.
If you look over the
shoulder of the person
reading the sentence, you
think, what's going on?
There's X's everywhere.
Why don't they see it?
But of course, they don't see
it because exactly where they
are looking, there
are proper letters.
It's a very, very strange,
very, very strange illusion
to be inside.
Another thing you
might be interested
in you might think,
yeah, but what's
going on when you're
moving your eyes?
I mean, all these letters
are changing, aren't they?
And they're changing from
letters to Xs and back,
and it's a bit odd.
Why don't I notice that
when I move my eye?
Oh, well that's because
when you're moving your eye,
you're blind.
You simply can't see anything.
Again, the consciousness
fools us completely.
As I look around the
room, I think, oh no, it's
all a smooth,
continuous perception.
Now I see this, now I see that.
It's flowing effortlessly
from one thing to the next.
It's not just staccato.
But, in fact, I'm seeing a scrap
of information, then blindness,
then a scrap of
information, then blindness,
then another scrap
of information.
And I'm putting
all these together
to give a sense of
a rich, continuous
conscious experience.
But it's an illusion.
Now, I want to
switch gears slightly
to think about a different
way in which our thoughts work
very differently from
the way we imagine.
So we improvise our way to
creating the visual world.
We scramble together a sense
of the richness of vision
through these tiny snippets.
The illusion is so convincing
we think it's real.
But let's now look at
something more abstract.
Let's look at perceptions
of people with emotion.
So here is a famous example by
Lev Kuleshov, a Russian film
director.
The name's the Kuleshov
Effect, much talked
about by Alfred Hitchcock, very
well known in the cinema world.
So this is done with stills,
but in fact, it's better done
with moving pictures.
So here is, I think it's
Isaac Mosjoukine, who's
one of Kuleshov's actors.
This is going back to the
early days of cinema in Russia.
And here he is paired
with a sad scene,
a child lying in a coffin.
And if you look at this
on its own, this pair,
you think he's looking in
a very subtle way, and kind
of nuanced way, looking
utterly grief-stricken.
On the other hand, if you put
him next to a bowl of soup,
he starts to look hungry.
And so, of course, you don't
see the effect quite as strongly
here because I put
them all together,
but if you block out the
others and just focus on this,
you'll find he's now
looking kind of interested
in this soup.
He's looking slightly hungry,
but he's very subtle, actually.
He's very, very, understated.
And here he is looking
somewhat lustful
as he looks at this
young woman here.
So now you see, again, he's such
a marvelous, marvelous actor
because of his incredible
understatements.
But of course, you
will have guessed,
this is the same picture.
But indeed, I think this
is Kuleshov's great insight
is that when we're
interpreting a face,
we interpret a lot of
the emotion in that face
based on the context.
So in fact, a lot of
the secret, at least
I think in his view
of good acting,
is not to be too expressive.
Because you want the viewer to
impose the appropriate meaning
onto your face and if you're too
expressive, they can't do that.
You're kind of
forcing the issue.
But that's interesting
because this gives you,
again, another illusion.
You think, when you look
around the world at faces,
you think all the
activity's in the face.
The face just has the look
of lustfulness or hunger
or sadness.
But in fact, you're
imposing that.
You're imposing that
because of your wider
understanding of the situation.
So we're improvising, not
just constructing the world
from snippets in
a way that fools
us, we're also imposing meaning
on snippets, here faces,
in a way that fools us.
We think that the
meaning is in the face,
but, in fact, the meaning is
being imposed from outside.
Here's another similar example.
This is a US senator
running for election.
Now, if you take this face
here and blow it up and cut out
everybody else, this fellow
looks really, very angry.
He does not look happy.
On the other hand, this is
Webb, Jim Webb, in his milieu.
In the actual election rally,
he's looking triumphant.
Now, how odd.
This is the same picture.
But in the context,
you realize, yeah,
look of triumphant delight.
Victory is going to be
ours, whereas here, he's
looking extremely unhappy,
indeed, and frustrated.
Things are desperate.
Now, that's interesting
because that same insights
applies to our interpretation
of our own emotions.
So you might think, well, if
I'm looking at somebody else,
maybe that face is
a bit of a cipher,
or maybe I do have to use other
information to quite work out
whether they're angry
or they're delighted,
or whatever it may be.
Maybe I have to impose
extra information.
But of course, for myself, I
just know what I'm thinking,
don't I?
And I think that's a really
fundamental illusion,
because actually, the
physiological signals
we get from our own bodies
are extremely sparse.
And roughly speaking--
and this is too crude,
but not much too crude--
roughly speaking, we have
two types of signals.
One is saying, what's
my arousal level?
So say I'm really sleepy and
bored or I'm kind of excited.
And the other one is
saying, I'm interested
and want to approach and
engage with this object
or personal thing.
Or the opposite, I
want to remove myself.
But that's about it.
That's about all
you have to go on.
So then you have to
take that very minimal
physiological signal, which is
like a very, very unexpressive
face, but an internal one.
And you have to think,
what's going on in the world,
and think, oh, I guess this
physiological signal must
be telling me I'm angry.
Or it must be telling
me I'm amused,
or it must be telling
me something else.
So your own physiology is like
a really, really unexpressive
face.
It's like the example
that Kuleshov gives.
And to actually make sense
of your own emotions,
you have to interpret.
So lots of lovely experiments.
I'm not going to
talk about them now,
but there are lots
of lovely experiments
where you can show that people,
in the very same physiological
states, will interpret that
state as anger or delight
or amusement, just based
on contextual shifts.
So the idea that the emotions
well up from within you
is really an illusion.
In fact, you've got a very thin
signal and you're interpreting,
what on earth must
I be feeling now?
Oh, I bet it's this.
Telling a story, improvising
your own emotional thoughts.
Let me give you an example of
the improvised nature of choice
now.
This is a famous experiment
done by Lars Hall and Petter
Johansson.
So Petter was a post-doc
of mine years ago,
but did this experiment
before he ever joined my lab.
And I can take no
credit for it, sadly.
I wish I could.
It's a very clever experiment.
So his experiment
works like this.
You give people two options.
And the task can be
anything, but the most famous
original task is, which of
these faces do you prefer?
So it's done with faces,
but it doesn't have to be.
I might say a bit about some of
the other options in a moment.
So you say to somebody, which
of these faces do you prefer?
And they say, oh, I think
that's kind of difficult,
but maybe I sort of
slightly prefer that one.
So step 1, look at these faces.
Step 2, that's my favorite.
Step 3, oh, well have a
closer look at that one then.
But step 4, trick.
I've given you the wrong one.
OK.
You do this task a lot, and you
only do a trick occasionally.
So in fact, that's
something like 32 trials
with three tricks.
And if you're wondering, oh,
I wonder, did they notice
the trick?
A, when you ask them, they don't
seem to have noticed the trick.
But B, much more cleverly,
Petter asked people--
Petter and Lars asked people--
well, they say, in the
experiment we just did,
half the subjects, we
did some tricks on them.
And for half, we did no tricks.
Which one were you?
So this gives them
the chance to say,
well, I did feel a bit funny
about something of them,
I bet you tricked me.
But they don't.
Most people don't.
About 80% of people don't
think they've been tricked.
20% do.
So what's interesting about
the people who've been tricked,
though, is that they are now
asked to explain their choice.
And they do, very happily.
They will give an
explanation for the thing
they did not choose, and it's
a perfectly lucid explanation.
It's just as long,
it's just as fluent.
It's just like all the other
explanations they give,
but it can't be anything
other than a rationalization.
They can't be doing anything
other than improvising,
because it's the wrong thing.
So the thought here is
that you're an improviser.
You're improvising
the visual world.
You're improvising
facial expressions.
You're improvising
explanation for your choices.
You're rationalizing.
We're all aware that we do
a bit of rationalization.
Delusion is thinking, yeah,
but sometimes I don't.
Sometimes I just
look deep inside
to the actual causes of
my own thoughts and think,
oh, I know what I
really was doing there
because I've gone
back, as it were,
into my own mental history and
picked out the real reasons.
But you can't do that.
All you've got is this
flow of experience.
All you've got is the sensory
experience of the world,
and you've got your own
voice and your own self
vocalizations, the little
linguistic stuff flowing
through your mind.
And you've got some
physiological signals.
That's it.
You have not got access.
You have not got some privileged
key into your own memory.
Here's a lovely
experiment from 1974,
a little ancient experiment,
but a very nice one.
There are many more
since, but this
is the classic, which
gives you a sense of how
powerful these effects are.
So this is an
experiment which was
done on the campus of
University of British Columbia.
And on that campus, apparently--
I've not been to this--
but apparently, there
is a very high and wobbly
bridge, like this one.
There's also a low,
non wobbly bridge.
What you do in
this experiment is
you station experimenters,
attractive female
experimenters, at one
end of the two bridges.
Male bridge crossers cross.
They're interviewed on some
fairly pointless question
survey type of study by
the female experimenters.
Then the experimenter says,
oh, for ethical reasons,
if there are any issues raised
by this survey, which there
certainly won't be,
you can contact me
if you have any problems.
Here's my phone number.
The question is, do the
bridge crossers call?
Now, the first thing is,
yes, they suspiciously
do call quite a lot, which is a
bit weird, because there's just
no issues raised by this survey.
But excitingly, and
this was the prediction,
the bridge crossers who've gone
over the high wobbly bridge
call about twice as often.
Now, why is that?
Why is that?
Why is it that a day
later, or two days later,
they pluck up the courage and
they phone that experimenter,
and on some pretext.
Why are they doing that?
Just because they want
to cross a high bridge.
Well, the answer is-- or at
least this is the prediction
and the explanation
in the study--
the answer is when you've just
walked across a high bridge,
you're really full
of adrenaline.
It's kind of a scary experience.
Then you meet someone and
you're full of adrenaline.
You think, wow.
What's with the adrenaline?
Well, obviously, this person
must be just fantastic.
I must be totally, totally--
did I just [INAUDIBLE] from me?
There's just this amazing
sense of chemistry.
What there is is a huge amount
of adrenalin flowing around,
but that's just because you
walked across a high bridge.
However, as the psychologist
call it attribution error,
you don't realize, oh,
it's the bridge, isn't it?
Of course.
You think, well, it
must be the person,
and therefore, you form this
belief that they are, somehow,
very, very attractive
to you and you really
must give them a call.
As I said, there are many,
many such experiments.
But the thought there,
again, is that we
have this idea that we have
mental depths from which things
kind of mysteriously appear.
So if you think, oh, well
who am I attracted to?
Well, that's a very
hard question, that is.
There's all kinds of deep
subterranean forces determining
this and they just burst
forth mysteriously.
I have these strong,
stable preferences.
They just come from nowhere.
I don't know where
they come from.
But actually, that's
a bit of an illusion.
In fact, you're trying to
interpret your own experience
as you're going
through the world.
If we trick you, we
distort that experience,
then you interpret it wrongly.
Now, why are people not feeble,
highly unstable creatures,
just flitting from one random
improvised thought to the next?
Why are we able to be so highly
integrated, stable characters
who are able to lead
organized lives?
Well, the answer I
want to give to that
is that you should think of your
mind as a bit like a tradition.
So the thought here
is that you can only
think one thought at a
time, but every thought
is shaping the
next thought and is
shaped by the previous thought.
So you're a bit like a drop of
water running down a landscape.
The way the drop
of water falls when
it rains, or those droplets
fall, is determined,
where they flow, is
determined by the landscape
that's already there.
But that landscape
is, itself, created
by all those previous droplets.
And of course, each new droplet
just makes a tiny change
to the landscape,
and will therefore
affect future droplets.
So you're like a
landscape created
by an endless flow of water,
whereas what there isn't
in the landscape is a sculptor.
You might think,
you've got to mean--
how do these rocks have
such interesting shapes,
or how come the
shape are so stable?
Or how come the different
hills have a similar look?
The answer is not that they
were created or designed,
or there is any
agency behind it,
they are the process
of a long period of one
each force, each little tiny
change, changing the next,
changing the next,
changing the next.
And I think our minds
are very similar.
But I also want to give you the
sense that the way in which we
are changed by our
experience is incredibly
flexible and creative.
So far you might think, this
is a bit of a negative story.
I thought I could
see this whole world,
I thought I could
interpret people's faces.
I thought I understood where
my feelings are coming from,
and you're telling me I don't.
This sounds rather bad.
But actually, I think
it's sort of the opposite.
I think in reality, we're
astonishingly powerful
creative machines.
We're able to make sense
of the world around us.
We're able to make sense of
facial expressions, experiences
in a way that is extraordinarily
labile, creative, inventive.
So I want to give you
just a hint of that.
And of course, then
we create traditions.
But those traditions are
not some blind copying.
They're the traditions
that we create
in culture, the arts, language,
that the extraordinary--
and, indeed, science-- the
extraordinarily complex,
rich things we
can create are all
created by gradual incremental,
one fourth at a time, growth,
on this great landscape.
So here's something a bit more,
but focusing on our creativity.
I'll put it from a
positive standpoint.
Here, in this example, we
have the wonderful creativity
of perception.
So anyone who thinks
in a negative mood--
some people in my family keep
saying things like this, well,
I'm just not creative.
My brain just doesn't
work that way.
Think again, when you look
at this amazing image here.
This is the image invented
by a Japanese vision
scientist, Idesawa.
And of course, you
can see that it
is a sphere, sort
of a snooker ball,
or billiard ball, white
billiard ball type of thing.
Pretty three dimensional.
And you can probably have a
sense, though it's an illusion,
but you happen to have
a sense of the whites
in the ball area here is
just a little brighter
than the surrounding white.
But of course, that's
not actually true.
What's happening
here is that you
are taking these pieces,
these exact pieces,
and turning them into
a three dimensional
object, a spiky sphere.
And that is an amazing thing.
So those exact spikes,
those fragments,
when they're organized
in a special way,
your brain immediately
thinks, oh, I
can see a clever way
of organizing these.
It's like a puzzle,
but the brain
can easily see the answer.
You can explain why
those shapes are
the way they are by
thinking, oh yeah,
they're all about the
same length, spikes.
They're cones.
They're black.
The little, white sphere.
There's all kinds of issues
with bits being cut off
by the background.
So you can see this
spike is rather short,
but of course it is, because
it's pointing away from us
and it's occluded by
the billiard ball.
And then this one, for
example, is coming towards me.
So all of this is
perfectly explained
by this amazing insight.
But that amazing insight is
something your brain just
creates in a flash.
So it's not you're poor or
kind of simple creature, which
is just being pulled or pushed
around by your environment.
You're an incredibly
powerful, organizing machine.
And that's think the
reason you can only
do one thing at a time.
When you're deploying your
concentration, your attention,
on a particular object,
you're able to bring
to bear all the other stuff
you know, all the experience
you have of, in this case,
three dimensional objects,
can be brought to make
sense of this thing.
That's a really
hard thing to do.
And that's why you can
only do one at a time.
But don't underestimate the
spectacular inventiveness
required to do it.
The possible number
of objects that
could underpin this set of
markings on the page is vast,
but your brain immediately
thinks, oh, white sphere,
spikes.
Another illustration is faces.
So here are some
found faces, faces
that just happen
to be in the world.
And I love these faces.
I think one of the things that's
nice about it is, first of all,
we immediately see them.
And they are nothing
like faces, are they?
I mean, they're nothing like
the faces that we see everyday.
You really have to take
a massive, creative leap
to think, whoa, you can think
that's a little like an eye,
and that's a little like an eye.
That's a little like a nose.
I suppose this is
kind of like a mouth.
Not very much.
You have to make an
enormous metaphorical jump
to get from actual faces
of actual people to these.
However, your brain's
really good at making
creative metaphorical
jumps, and it does.
The other thing I
want to stress here
is just how emotional
these faces are.
They are just as
emotional as any-- they
are laden with emotion
as any real human face.
For example, there's anger
to this face, but also
slight cross-eyed loopiness.
You're not quite sure whether
to be afraid of this face
or to think it's
slightly ridiculous.
This is an eager to please face.
He really wants you to like it.
It's trying to
look kind of happy.
But it feels like I'm trying
to hold things together,
but I'm not quite sure I can.
It's a cheese grater,
but nonetheless, that's
how it seems.
What about this fellow here?
He's kind of a benign
face, a little bit drunken.
You wouldn't want to ask
him a difficult question.
He's looking a little bit
like he's a little lost,
but nonetheless, he
sees a friendly face.
This poor fellow, this face
here is very, very concerned.
There's a definite sense
of fear and confusion.
He doesn't know what's
going on, but it's not good.
Now, how is that possible?
How is it that we not
only see these as faces,
but we impose such
richness on them?
It's amazing.
Of course, these faces don't
really have an inner life,
but we impose inner life,
we impose interpretation
on everything, including each
other, including ourselves.
To finish, I want to
finish with an analogy,
going back to the
metaphor the mind is flat
and the idea of mental depth.
And I want to do
that by pointing
out some lovely figures
by an artist earlier
in the middle of the 20th
century, Oscar Reutersvard.
And he produced what
many of you will think
of as Escher-like like stimuli.
Many of you will know Escher.
But around the same time, and
in some cases before Escher.
And that's rather beautiful.
In here are some stamps.
He's a Swede and the
Swedish postal service
used some of his figures
on a famous set of stamps.
Now, the nice thing
about all of these
is they are impossible figures.
So if you look at them casually,
you think, this is some blocky,
three dimensional object.
If you look more
closely, you start
to think, hm, where's the front
and the back of this thing?
And from further
contemplation, you
start to realize
these figures actually
don't make any sense at all.
So if you look at
this one, for example,
this is, essentially,
the Penrose Triangle.
Reutersvard invented
the Penrose Triangle
around the same time as Penrose
and Penrose's original paper,
completely independently.
So it looks like,
starting here, say, it
looks like we're going back.
Back we go, back we go in
space, further and further away.
Now let's go down here.
Oh, we're going back further.
Yup, further we go.
And then we've gone back.
We've gone back into depth.
We've gone back
further into depth.
And now we're just
going vertically.
That's level in depth.
And yet, we end up
where we started.
That's a bit weird.
So it's like I started
here, I went back a bit,
then I went back a bit
more, and then I went up,
and I ended up where I started.
And that can't be right, can it?
And indeed, it can't be right.
This is not a possible
three dimensional object.
What about this one?
Same sort of thing.
Just trace around here
and you'll find something
very odd happens,
as soon as you start
back to where you started.
It just makes no sense.
Similarly, this one, too.
These are very
interesting, in themselves,
when you think about what
they mean for vision.
Because they're
telling us that we're
only able to organize one
part of the stimulus at once.
If we can organize
the whole stimulus,
these are very simple compared
to the world around us.
We should immediately
say, these are impossible.
The light should be-- the alarm
bells should be, going off.
Because if we could try to
integrate this entire stimulus
in one go, we'd fail,
because it doesn't
have any interpretation.
And we think, oh,
impossible object.
But in fact, we only realize
it's an impossible object
by going slowly.
We think, well, that
didn't make sense.
That didn't make sense.
That didn't make sense.
Oh, but hang on.
I'm trying to piece it together.
Oh, they don't fit together.
That's an effortful,
slow, difficult thing.
So that's interesting
in itself because it's
an illustration of the
sequential local aspects
of vision.
You feel you can, in some
sense, see the whole object.
And you can see that
it's three dimensional,
but that must be an illusion,
because if you could really
see it, you'd realize it
wasn't three dimensional.
But it's an interesting
illustration in another way.
These are stimuli that look,
locally, like they have depth.
You look at any piece of
them, perfectly reasonable,
depth-like object.
You try and put the
different pieces together,
they do not fit together.
And that is a very interesting
analogy for the mind,
in general.
If I ask you to
explain your actions,
or justify your beliefs,
you'll tell me a story.
Why did you take a
particular route to work?
Oh, I have a story for that.
Maybe you take the tube.
I say, which tube?
Oh, you have a story for that.
And I ask you more
questions, there'll
be more stories, and
more and more and more.
And they all sound
very convincing.
They're just like each
patch of the image, which
looks three dimensional.
But if I'd try and get you to
put those stories together,
they will not make sense.
Now, this is the thing
that people realized
in artificial intelligence
in the '70s, and before,
when they started to try to
get knowledge out of experts.
So you'd think they're experts
knowing how they do things,
so you just ask them.
Well, you're an
expert chess player,
so what do you do in
this position and why?
You tell me.
And the expert
chess player says,
well, this is obviously
the right move,
and well, here's the story.
But then you do
it again and again
and again, and the stories
do not make any sense.
They are not coherent.
Each story sounds fine, but
they do not fit together,
because they are rationalizing.
They're not really going
in and saying, actually,
I have this deep
insight into my mind.
I'm just looking at
these inner thoughts.
No, they can't do that.
What they're doing is
they're rationalizing,
and they're rationalizing
in a very convincing way.
But all the different
bits of rationalization
don't fit together.
So I think, in fact,
that the mind is flat.
The cover has
exactly this quality,
has the look of a three
dimensional object,
but it isn't.
And this is to illustrate
the idea that, actually,
your mind itself, as you
traditionally conceive it,
as we traditionally conceive
ourself, is, itself,
an impossible object.
We imagine that I don't
just have one or two beliefs
that I've just thought
of at the moment,
each belief is justified by
a huge network of beliefs.
It just goes on forever.
And my motives, I can
think of one or two,
but there must be
many, many of them.
And they themselves
are all carefully
interlinked and intertwined.
But in fact, as soon as
you start to explore that--
and that's quite a
big theme of the book,
which I haven't really
talked about today--
but as soon as you try
to articulate and explore
the connections between all
those different snippets
of information, snippets
of beliefs, snippets
and motivation, they
do not fit together.
In fact, your mind is an
impossible object, just
the same sense as Reutersvard's
strange, impossible objects.
So I think the
take-home message is
that we are amazingly creative,
stupendously free improvisers,
and each improvisation
is done upon the basis
of the last improvisation.
And we're so convincing
that we think as a script.
It's like improvisational
actors who are so good,
you think, oh, you just
learned that, haven't you?
Somebody wrote that script
for you, you're reading it.
But there is no script,
they are improvising.
And we're so fluent and
we're so good that we
don't realize, in fact, we're
making it up as we go along.
Thank you very much.
SPEAKER: We do have
time for questions.
Please raise your hands.
AUDIENCE: So I don't
really know how
this is different from
exactly what Freud said.
I mean, there, we have
a set of illusions,
slips of the
tongue, or whatever,
that is created by the
dynamics of improvisation.
You created this kind of
strange thing called a script.
Everybody knows
it's not a script.
Actually, there are
some internal generative
processes which produce
perceptions and these can
be, more or less, integrated
to different people.
So I just want to know exactly,
it seems as if Freud was here--
if Freud was here, he wouldn't
have any problem with anything
you were saying.
So could you just
deal the deathly blow
to the whole thing.
NICK CHATER: Yeah.
I'd like to think Freud would--
I'd be delighted if Freud
turned out to agree.
But I think he wouldn't, because
for Freud, the conscious is
only a tiny fragment of thought.
So I would agree that
there's a lot of stuff--
the brain is doing a lot of
stuff we're not conscious of.
In fact, everything,
pretty much.
The only thing we
are conscious of
are, essentially,
sensory experiences.
And I would include in that
both imagery and also language.
In a sense, you are only
conscious of very neurosensory
experiences.
That's it.
But I think for Freud, he'd
say, no, no, that's right.
Those are the thoughts
you are conscious of,
but there are other things which
are a bit like that, they're
just hidden.
So there's something else,
which is a bit like--
Freud would say, I think,
there's an iceberg.
And there's the tip
of the iceberg, which
is the conscious
thoughts, and then
below that, there are all kinds
of other unconscious processes.
Now, I want to say, no, that
iceberg metaphor is a mistake.
The things that are visible
are nothing like the things
that are invisible.
And so what's invisible
is, essentially,
the vast tradition, the vast
history, of previous thoughts
you've had.
And what you're
doing when you're
coping with the
current situation
is you're drawing on all
those past experiences
and previous situations.
You're not actually-- there's no
underlying generative mechanism
you can refer to.
What you've got,
as it were, lateral
connections between one
thought and the next.
AUDIENCE: So it's a disagreement
about the content of the nature
of the things underneath.
Because I suppose when you're
describing those illusions
to us, what you're doing
is equivalent to a kind
of therapy, and making
conscious into thoughts
the processes that
resulted in that illusion.
NICK CHATER: Yes,
that's absolutely right.
But the way I would
think of it is
that we think of it
as a process where
something that was previously
unconscious is now conscious.
But I think that,
itself, a mistake.
I think it's not that
there was a thought which
I wasn't aware of and
now I am aware of it,
it's simply that the
mechanisms are completely
and utterly different.
So for example, if you think
about the patterns in language,
they're very, very complicated.
We learn them, it appears,
in a very exemplar-based way.
So I hear different phrases, I
generalize from those phrases.
I gradually assemble
a language as a child.
And that language has all
kinds of complicated patterns.
And as a linguist, you
might say, oh look,
you didn't know about this
complicated rule or pattern,
did you?
And the answer is
absolutely not.
The explicit task of
finding patterns in language
is a total mystery to me.
But I think what's
going on there is not
that you're making explicit
to me something I knew,
it's just that I've learned
all these fragments,
and these fragments
create this pattern
and I never knew nothing
about the pattern.
I only knew about the fragments.
The things I know about
things that are always--
either they're conscious
now, or they were.
So yes, it's a disagreement
about what the substrate is,
yeah.
AUDIENCE: This is an
important question
that was asked about when
you argue with psychologists.
So would Freud say,
yeah, I agree completely
with the landscape image,
except that the landscape is
moving by itself, or is
changing with other [INAUDIBLE]
NICK CHATER: Yes.
I think that's probably
right, actually.
So I'm very much hostile
to the idea-- at least
I think there's not much
experimental evidence
that the landscape
is moving by itself.
I mean, in fact, the brain--
when you are focusing
on a particular task,
your entire brain--
I mean this is too extreme,
but large areas of your brain
are really focused on
whatever that task is.
So if you're reading
a word, you're
listening to a piece of music.
If you're locked on
to that stimulus,
the vast tract of
your brain will
be active in locking
onto that stimulus.
Now, of course, there's lots
of autonomous stuff going on.
You're still breathing.
You're not falling over.
There's all kinds of
things that are actually
relatively separable
from general cognition.
But high level
cognition, the ability
to freely attend to one
thing and then the next,
seems to be roughly sequential.
And whatever's locking
onto it at any given moment
is roughly obliterating
the possibility
of locking onto anything else.
So I think that's exactly right.
I think at least
a popular illusion
we have is that, as well
as the conscious processing
is going on, my brain just doing
all kinds of secret processing
in the background, just thinking
about the kinds of things
I normally think about,
but thinking about it
in the background.
Whereas I think the
brain is thinking
about lots of other
things, but they're
things like not falling
over, and very different
in character.
AUDIENCE: A different
sort of question.
One characteristic of
many autistic people
is that they find it difficult
to infer emotion from faces.
What does your theory
say about that?
NICK CHATER: That is a
very interesting question.
I don't have any
specialized knowledge here,
but I do think it's
possible, at least
it's interesting to imagine,
that perhaps the big problem is
the contextual integration
of context, which
I think some theories of
autism do focus on the idea
that, generally, trying
to create wholes out
of many individual parts
is quite difficult.
There's a tendency to focus,
if you have autism, on part,
and analyze those
parts in detail,
rather than be
able to integrate.
So it could be, at least
one part of the story
could be, that trying
to interpret faces
requires this integration, not
just of the visual stimulus,
but actually, all of the
surrounding stimulus, which
may be difficult to do.
AUDIENCE: Some of
your definitions
seem a bit tautologist.
So you say there's only
conscious thoughts,
but you define thoughts as
things which are conscious.
And you say you can only
do one thing at once.
But, say, my hobby is
dancing, and while dancing
with a partner, I can hold
a conversation with her.
And you would say,
oh, the only thing
you're actually doing is the
conversation and the dancing.
It doesn't count as a
thing because you're
doing it at the same
time, so it feels a bit--
NICK CHATER: Yeah.
Let me make that a
bit more precise.
The more correct story, but
a bit more complicated story,
would be to say, any bit
of brain, I would argue,
can only do one thing at a time.
So you've got a complicated
set of networks in your brain.
Each network can only
do one thing at a time.
Now, if it's the case that you
can take on two tasks, which
as it happens, do not
use overlapping networks,
then you're fine.
Now, if you're
beginning dancing,
this is not the case, because
it's so much top-down control,
which is required to keep
you doing the right moves
in the right order.
Then there's a lot
of overlap between
the same top-down
mechanisms you'd
need to run a conversation.
But if it's a too complicated
task, you're done for.
But for things that
you've done a lot,
some tasks are possible
to run in parallel.
Now, the example I
talk about in the book
is a very nice examples of
touch typing and sight reading.
Is that right?
Yeah, sight reading and
shadowing, that's the one
I want to focus on.
So here you are as a
very experienced pianist.
Your sight reading
a piece of music,
and also, you're hearing
in your ear a voice
and you just have to say
what the voice is saying.
And wonderfully,
you can do that.
Not if you're not a very good
pianist, you'd totally fail.
But if you're a good
pianist, the sight reading
is relatively
autonomous process.
The re-generating
what you're hearing
is a relatively
autonomous process.
It wouldn't be if it
was in a language you
weren't very familiar with.
That would become a
very hard process.
So there has to be strongly
automated processes.
And so yes, there are a few
examples where you can really
cleanly see that the brain
networks are not overlapping,
and then we're fine.
But that's really the exception.
But they're very
important exceptions,
very interesting exemptions.
Oh, for example, I should
say driving is actually
not one of these exceptions.
So if you happen to think,
as I'm driving along
I could have a chat
on my hands-free phone
with no interference,
you'd be absolutely wrong.
There's lovely
experiments showing
that, even if you have to do
the most trivial ordinary task,
monitoring some auditory
signal, that really
screws up your ability
to brake, for example.
So our intuition's about
what we can automate
and what we can do
separately is not very good.
Often, we're actually swapping
from task to task very quickly.
AUDIENCE: My understanding
is that sleep
is used for the
organization of memories,
so how does that fit
into your theory?
NICK CHATER: Yeah, so I think
it's not very well understood
how sleep plays a
role, but it does
seem to play an important role.
And I suppose this account can
deal with that to the extent
that that process is
mediated by dreaming.
Because in dreaming,
you are just replaying.
This is the whole replay theory
you get a lot in neuroscience.
So the idea is that you're
doing something a bit
like being awake,
and you're doing more
a conscious flow of experience,
and that is allowing
you to reprogram the system.
If it's case, what this
approach rules out is the idea
there's some other
process which is not
going through the
processes of, essentially,
the conscious experience,
which may be too strong.
This is a particularly
strong view.
I think it's roughly right.
There might be some
processes which
are going on at a completely
unconscious level.
But I want to keep going with
the strongest possible stance
until I'm absolutely
forced not to.
But I think that's
broadly right.
For example, if you give
people problems to solve,
and if they sleep on
them, yes, they're
slightly quicker than if they
hadn't slept on them, to solve
them when you ask them again.
And that seems to be pretty much
entirely explained by the fact
that they've forgotten the
errorful ways they started
to try to solve
them the first time.
So I give you a problem.
You say, oh, it's like this.
You're wrong.
If you're right, you solve it.
If you're wrong, you come
to the wrong mental set,
the wrong interpretation
of the problem.
You get stuck,
then you get sleep.
You've forgotten now,
and you're quick.
But this seems to be no
evidence that you solved
the problem in your sleep.
It's a really
active reprocessing.
We intuitively feel we're
doing that from time to time.
It's almost certainly
an illusion.
AUDIENCE: I can remember
that about this, I just
wanted to make a remark.
I remember that Michel Jouvet,
I think the discoverer of REM
sleep in cats, suggested
that you make of the dream
as you recall it.
In fact, you don't recall the
dreams, you just pick it up.
So that kind of goes
with what you're saying.
But my question was about
thought without language,
and mostly mathematicians,
like [INAUDIBLE]
or how they solve a
problem by [INAUDIBLE]..
And what do you make of that?
NICK CHATER: Yeah.
I mean, I think that's
very, very interesting.
So one person I
discuss in the book
is [INAUDIBLE],, who is this
phenomenal geometric genius who
was able, in according to
his own description, a very
geometrical way, solve
very deep problems
and then write down
the symbols later.
And I think the fact that he was
experiencing this imagistically
is not at all accident.
And that's what
he's conscious of.
What he's conscious of is the
visual traces of the thoughts.
But only you're conscious
of, I think, is the sensory.
Now clearly, it must be
that these thoughts, as he's
generating them, are being,
I think, created one by one
in the moment.
He's not the reading
off from something
in a mathematical textbook.
But he creates these
thoughts in the moment.
But all he's actually able
to consciously report about
is these imagistic traces.
All you're conscious
of is the surface
of your thoughts,
nothing beyond that.
But I do think the
fact that people
have a very strong
sense of imagery
is important in mathematics.
It's absolutely very important.
I do think that's a phenomenon.
I think it's really
probably rather crucial.
AUDIENCE: [INAUDIBLE]
about free will?
NICK CHATER: Not necessarily.
I am, however, a great
believer in the utility
of the idea of free will.
I completely believe in
a deterministic world,
or a deterministic [INAUDIBLE]
quantum mechanical effects.
But I think the intuition we
have of having ourselves being
free is that we have
the ability to create
the interpretation of the
present and the interpretation
of what we should do
freshly in the moment.
And I think that's
absolutely right.
So you could have a story
which says, well, you're kind
of in a behaviorist nightmare.
You've laid down
various associations.
And a stimulus comes
along and you just
find yourself unavoidably
charging towards the fridge
and eating cheese, or
whatever, because of that bell.
There's no stopping it.
That would be a very
different story.
I think we're
extraordinarily clever,
creative, metaphorical
creatures, who are
very flexible in our behavior.
Now, you might say,
well, but at base, it's
all determined,
isn't it, really?
And I think the answer to
that is an answer of Quine--
I think probably goes
back before that--
the philosopher Quine
had this nice comment
that says, of course,
free will's about being
free to do as you will.
It's not about being
free to will as you will.
So there's something inherently
bonkers about that idea.
So being free is
to have the ability
to think flexibly, decide what
you want to do, and to do it.
Not being free is
being controlled
by impulses that continually
take over and force you
down channels you
didn't want to go down.
So that's the sort of
soft science-y, not
philosophically deep solution.
But I like the
idea of free will.
I think it's actually a deep and
meaningful intuition about us,
and I think it distinguishes us
from a lot of other creatures.
AUDIENCE: It seems
common to get insights
that appear fairly fully
formed, say, we're all showering
or something and
it's out of the blue.
How might that kind of
thing might be explained?
NICK CHATER: Yeah.
Well, I think there's
quite a lot of work
on this in the world of
problem solving research.
And what seems to be
going on is that you've
got a lot of prior
thinking, then
you have a clue, which you
hadn't thought of before,
a little insight.
You think, oh, maybe
this will work.
And mostly, it doesn't.
So the illusion is that when it
does work, you think, oh yeah,
the whole thing's
clear to me now,
because I see roughly
how it's going to go.
And look, I'm putting
the pieces in.
Oh look, they all fit.
I sort of saw that all along.
And I think that's a sort
of retrospective trick,
because we all equally-- and
I certainly have this a lot,
we probably all do--
you have a problem.
You think, oh, I
think this is it.
And in fact, it isn't.
You try putting pieces together,
nope, that doesn't work.
OK, let's do it again.
But when it does work,
you have the feeling
that, oh yeah, I did
see there correctly
all the pieces fitting
together, because they did.
But I think that's a
bit of an illusion.
So there's an awful lot
of-- a lot of artists
and scientists have
the story about saying,
oh in a single
moment, I suddenly,
vividly, completely saw the
entire score of my sonata.
But when being
pressed, they say,
oh well, it did actually take
me two weeks to write it.
A lot of hard thinking, but also
saw how it was generally going.
And I think that sense of, I see
the whole, it's all clear to me
now, is something that--
there's a slight
selection bias there.
However, of course,
it's still true
that sometimes you do have
organizing thoughts, which
allow you to see something in a
more abstract way, which does,
actually, give
you the structure,
which will help
everything fit together.
But there, you're thinking--
it's a bit like seeing a face
and thinking, I'm not
just seeing the face,
I'm also seeing the eyes, and
the eyelids, and the pupils.
And you're not.
When you're seeing the face,
you're seeing the face.
You look at the eye,
you're not seeing the face.
So we have the
illusion, if you're
looking at the whole
body, you really
aren't, in a very real sense,
seeing the face anymore.
But we have the illusion, if
I have an abstract, high level
thought, I'm seeing, grasping
all the internal structure,
that's a bit of a fiction.
SPEAKER: We are out of
time, unfortunately.
So thank you again,
Professor Nick Chater.
[APPLAUSE]
