This is the Convergent Science Network podcast. Leading researchers in the domain
of neuroscience, brain theory and technology are interviewed by Paul Verschure and Tony Prescott.
All right, this is Paul Verschure with the Convergent Science Network podcast
and I'm here with the first speaker of our Barcelona Computer,
Brain and Technology Summer School, Samir Zeki.
So Samir, it was really great to hear you speak this morning about the work
you've done over the last decades on the visual brain.
Thank you. But before you delved into the science of it, you made some remarks
on multidisciplinarity and your views on that.
So why was it important to you to sort of highlight your perspective on multidisciplinarity
before you went into the science of the visual brain?
Well, it was important for me because you introduced the session today by talking
about how your institute here, your university,
is interested in engaging in the arts and in the sciences and is not a unimodal subject.
Now, the idea of being interdisciplinary is very fashionable at the moment and
they keep telling us how we should be interdisciplinary. disciplinary.
But the reality is very different. The reality is that people are extremely hostile.
Now, let me just explain to you why I think this does not work so well.
Because when you go to research councils, you have to choose panels.
Panels that judge, say, neurobiology will have no knowledge of art or physics or philosophy.
And therefore, they say, well, we don't think this is sort of philosophical
enough or artistic enough, and the others do the same.
So doubts are raised, plus the university structures, with one honorable exception,
I have to say, which is my college, University College London.
The structure of universities also is not conducive.
So in most universities now, you don't find a department of anatomy anymore,
but you find a department of cell and developmental biology.
So it includes things which are allied.
But you would never get a department of, say, neurobiology and philosophy.
They won't do it.
And I think it's a great pity, because I think that the problems asked by philosophy.
Well, let me put it this way.
One of the functions of the brain, of the main function of the brain,
is to acquire knowledge.
To take action, for sure, but to try to acquire knowledge for it.
And one of the main problems of philosophy as a discipline is the problem of
knowledge, of how we acquire it, and how certain we are of what we know.
Now, what could be more natural than to ally these things?
But you try to get some money for that, and you will not get it,
because the whole structure of universities is not conducive, and research councils.
I just want to just end up by one thing which I said earlier on,
which is that I am appalled by the advice given by one academy to young people
who are interdisciplinary in tendency,
that don't declare it.
Go and master a field and then come out of the closet.
Come out of the closet and declare yourself as you're interdisciplinary. disciplinarian.
I think it's one of the most shocking bits of advice to give to a young aspirant
researcher, when you should be asking them, settle on your problem and then
use whatever approach you need to use and learn it.
And young people are very enthusiastic and they're very inspired and they're very able to do that.
But if you channel a person to spend 20 years to, or whatever they want to have
in mind, to learn certain techniques and become masters before you will reach
some interdisciplinarity, I think it's very poor advice.
Well, then something might lead to a self-fulfilling prophecy of a unidisciplinary
person. It will. It will. A highly specialized person.
Absolutely. So in that context.
You have linked your study of the visual brain also to the arts and to aesthetics,
and we'll come to that later.
Also, given your current position as professor of neuro-aesthetics,
but the foundation on which you made that jump was your understanding of the visual brain.
So now in your talk, you emphasized very much that you were advocating an alternative
view on this visual brain. Yes.
And this alternative view was very much going away from this rather sequential,
linear processing structure that would go from retina to the left, to the right, to V1, etc.
So what are the main outstanding differences between this traditional view and
this new view that you now advocate?
So there are three or four main differences, much of them rooted in new knowledge
or not so new knowledge, which has been around for between 40 and 20 years,
and some of it is accruing.
One is that the common view that the sole input, visual input to the visual
brain or to the rest of the brain is through the primary visible cortex is simply not true.
There's a lot of anatomy to show this, and it's been there for 50 years.
The second point is that the systems that feed directly into visual areas outside
V1 are capable of eliciting a conscious visual experience.
So, to experience a visual stimulus consciously, you don't need V1,
either as a pre-processor or a post-processor, as so many people assume.
Thirdly, the fact is that you do not see all the different attributes of the
visual world at the same time in the micro-perceptual world,
let's say below 150 milliseconds.
We all assume that you did, but in fact you see color before you see form,
before you see motion, with differences which are quite significant,
say 80 millisecond between color and motion, color coming first.
And finally, the principle which has been universally ignored,
And I think it's a pity, really, which is the principle of asynchrony,
that the brain undertakes asynchronous operations all the time.
Now, if you factor the asynchronous operations all the time,
then I would think that one would have to modify quite considerably the computational
theories of how the visible brain functions.
And in a way I'm a bit surprised maybe not a question of interdisciplinarity but the extreme of.
Specialization I'm a bit surprised that there's no computational theory for
example today that takes into account the fact that the operations of the visual
brain are highly asynchronous because lots of things follow from that,
so So I'm not advocating at all throwing out previous findings,
which are very good and robust and solid, and there have been many, many exciting ones.
I'm simply saying that these have got to be all integrated together.
And if you do that, you get a different notion of how the visual brain functions
than the one we currently have.
But the examples that you provide are sort of questioning this notion of a single hierarchy. Yes.
But does that imply that you believe that there are multiple hierarchies, and if so, how many?
Yes, it certainly implies there are multiple hierarchies, and there are at least
three with subdivisions within each.
But I cannot tell you how many. I think there may be quite a few.
In fact, there may be quite a few which use the same systems,
the same hierarchical systems.
The important thing is, one, is that the single hierarchy is an idea first put
forward by Hewlin is not true, even for the form system.
They base their whole theory on the form system, but even in the form system,
that's not entirely true.
And the notion that the hierarchies.
Temporarily involve always activation of V1 first in the other areas is not true.
And thirdly, that the perceptual hierarchies would obey the latency hierarchy is not true.
So you've got to find a common denominator. What can that be?
That denominator is that hierarchies, which of the systems, with our several
hierarchical systems operating in parallel, Which of these has precedence and
priority depends upon the task and the stimulus.
To my knowledge, that explains it all as of the present time.
But of course, you may have to change it if new facts come into light.
But now, we could argue that there might be three perspectives on hierarchy, right?
We might have anatomical hierarchies, physiological hierarchies,
and functional hierarchies. Yes. And they're not necessarily identical.
Well, exactly they're not. Right. But in terms of the anatomical hierarchy,
what would you see as the key pathways when we talk about the visual brain?
Right. See, there are two different kinds of anatomical hierarchies.
One is the hierarchy through V1, retinal lateral geniculate nucleus V1 to other visual areas.
Another hierarchy is, of course, retinal lateral geniculate to the specialized areas and to V1. on.
But there are other hierarchies.
I mean, within the anatomical system, people have defined hierarchical systems.
This is started with Pandya and his colleagues.
They defined find it as an area that projects to a higher cortical area,
projects to layer 4 of that cortical area, and a area that recedes from a higher
cortical area, recedes and puts it into the upper and lower layers.
So you've got some kind of arrangement like that, which seems to be true everywhere.
So you can classify areas into a hierarchy with respect to each other.
But now look at it. Area V1.
Projects to the lower four of area V5. Hence, you'd say that area V5 is a higher
area compared to area V1.
But actually, if you look at the arrival of signals in these areas with fast
motion, you find that V5 receives them first.
So that latency hierarchy does not obey the anatomical hierarchy.
Now if you look at perceptual mechanisms, you find that if it is.
The latency of arrival of signals into V5 with fast-moving stimuli is 28 to 32 milliseconds,
it happens to be quite close to the latency of arrival of color signals into
V4, which is in the sort of 30 to 40 millisecond range.
Now you would assume that you see color and motion roughly about the same time,
or if anything, you would see fast motion before you see color.
Not true. You see color before you see motion by 80 milliseconds.
So the perceptual hierarchy does not obey the physiological latency hierarchy.
That is why I have sought to find a system that would that would explain all these hierarchies.
And the only one I can find is a task and stimulus-dependent one.
But automatically, what you've advanced was an idea that's actually a parallel
feed-forward pathway that is not running over the LGN into V1,
but it runs over the pulvinar directly to higher visual area,
higher cortical visual area. Yes.
So would that be then the foundation for the anatomical hierarchy?
Well, they're all hierarchical. I mean, there are three, at least three.
One is retina, LGN, V1, and then visual areas.
One is retina, LGN, directly to the visual areas. One is retina,
pulvinar, directly to all of these visual areas.
I suspect that the pulvinar one, and I don't know much about it.
I know that the anatomy exists. That's well known, it's been known for 50 years almost.
But I suspect that the pulvinar system may be much more concerned with attentional
mechanisms, which of course every area has them.
I mean, attentional mechanisms are involved in every area. So I suspect it is partly that.
I think there is reasonable evidence to show
that the capacity of V5 to register consciously the direction of fast-moving
stimuli is more dependent—in the absence of V1—is more dependent upon the LGN than the pulvinar.
But now, if we go back to this anatomy and the notion of hierarchy.
And we take also into account that anatomically, thalamus and cortex are strongly
and recurrently coupled. Yes.
This might make the notion of a hierarchy also more complicated,
because it's not just that thalamus is the driving cortex, cortex in the journeys.
Absolutely. It's obvious. Absolutely, absolutely.
But you see, when you look at these, there are massive, massive connections
from the cortex to the thalamus.
When you do that, then you have to ask the same questions you asked about arrival
of signals in the visual area.
Do all the inputs to the thalamus from the visual areas arrive at the same time?
And probably not, because these different visual areas complete their perceptual
tasks at different times.
So you're right, and this pushes things further still, but it can still be accommodated
within in the context of what I was saying.
Okay. So now Murray Sherwood, for instance, in how he describes these cortical-thalamic interactions.
He's also talking about a very specific bias in how the recurrence between cortex
and thalamus is defined,
where lower, what they would call lower cortical areas, would already have collaterals
projecting into the thalamic nuclei that serve higher-level cortical areas.
So that might imply that there's an anatomical preference hierarchy,
if you want, in terms of how signals are propagated through that system.
Would that still fit your picture or would that be more problematic?
Well, let me say that I haven't actually really thought about that,
so I think I'd better not speculate on that. That's good. Okay.
So here we have an anatomical picture, but in some sense we're not considering
other subcortical visual areas like the superior colliculus.
Can you really be sure that the superior colliculus is not another hub in this
kind an anatomical arrangement. No, it is a hub. It is a hub.
I mean, every single visible area projects the superior colliculus.
Now, what it does is not so clear.
It's a bit... Part of the input to the pulvinar probably comes from the superior
colliculus, but the projections from the cortex of the superior colliculus may
be very important guiding eye movements.
They work one way or another. But you see, there you raise a question which
was raised this morning up to a point.
Given that each visible area projects to the superior calculus and projects
to the LGN and projects to other areas, there must be some selective basis on what's being relayed.
So how does that work is anyone's guess, but it's a general problem of great
interest for all cortical things.
What is the selective process that dictates if indeed there is one?
Because an alternative would be that an area sends out signals to all the areas
with which it's connected, and it's up to the receiving areas to sort it out. That's an alternative.
Both may be working, but it's a major problem.
Anatomically, imagine you wouldn't know anything about the physiology of this
system If you would just follow the wires, you would be hard-pressed,
I think, to identify unambiguously a hierarchical relation.
Because in some sense, all these structures communicate with each other one way or the other.
Yes, indeed you're right. And the reason why they did identify a hierarchy,
this is one thing which has remained from the 1876 discoveries of Salman Hentron.
The reason why they did come up with a hierarchical doctrine is that the retina
projected to LGN projects to V1, and they couldn't trace it beyond V1.
And so they said that this is the hierarchy. And it was entirely out of the picture.
However, let me just say that when I described that there were multiple projections
from each point in V1 to visual association cortex.
I think almost nobody read into it that there must be a function of specialization.
It's only when I did the physiological experiment.
But then people may not have thought about it very much.
But in some sense, so your proposal now was to say, well.
There are multiple, but with a finite set of path, hierarchically organized
pathways that structure the visual brain.
And that would, two of them run over LGM and one run over Povilar.
Yes, that's your proposal.
But if you just look at the anatomy as we now discuss it, couldn't you argue
that from an anatomical perspective, it's actually a non-hierarchical system,
but it's a physical substrate that could accommodate many possible functional hierarchies?
That's exactly what I am arguing.
I mean, it's hierarchical formally in the sense that it includes sequential stages.
So for all three systems, you've got retina, LGN cortex, or retina-povnar cortex.
So it's formally that way.
But functionally, it is as you described it.
That's what I'm saying. Okay, good. Then I got it.
So dynamically, okay, we have this idea now.
We have this rather omnipotent substrate that can, dependent on task,
as also I call it, configure itself dynamically for certain hierarchical process simulations.
This is also confirmed by the very specific latencies that you observe,
as you already described.
Yes, yes. Like color before motion. Yes, yes, yes.
But now you can argue, well, some of these latencies might be imposed dynamically
and others might be really fixed given your substrate.
I mean, if you have to cross more synapses, it will slow the signal down more
if you cross less synapses.
So of these latencies that you look at, which of these are indicating really
physical limitations of that system?
And which of those do you believe are more dynamically configured dependable tasks?
Well, I mean, you have to assume that the latency, the physiological latency now,
that when an impulse activates an area sufficiently for it to be detected,
then that it is somehow inducing an activity in that area which does something.
Now, what it does is not clear, of course not.
But that's very different, of course, from the perceptual latency,
and you cannot predict the two. I mean, you can't pick one from the other.
So you have to factor in another issue here, which is,
what are the computational requirements within an area, or what are the procedures
or algorithms or programs or concepts within the area, which it has to go through
to generate its construct?
I mean, for generating colors, the brain has got to compare the wavelength composition
of light coming from many different areas.
All right? To generate motion, you've got to look at the signals coming from
two successive points in time.
And so you've got a variety of different tasks which have different computational
requirements, which also must dictate.
Now, there is another factor which compensates up to a point, which is,
so you talk about the number of cells interposed between the stimulus and the area in the cortex.
We know that it's quite limited in the retina. You know exactly what they are.
They must all go through the rods and cones, then the bipolars,
and then the ganglion with the amacrins in between.
And the same is true of the LGN. But then you've got another factor,
which is the diameter of the fibers, the speed with which they deliver their signals.
And in a way, I would have thought that the fact that the motion system has
got large diameter fibers, which deliver signals rapidly,
is possibly, I'm not speculating, is possibly a compensation for the fact that
the working out of motion is slower than that of color.
So you've got to factor in that physiology and anatomy as well.
If you talk about a dynamically defined hierarchical relation,
let's say from feet forward and top down, you would expect that this would modulate
the physiological latencies in that system.
If I expect the stimulus, you would expect that also the physiological processing
is more efficient, more rapid.
So how big do you expect that modulation to be in let's say your standard visual detection tasks.
Well, speculatively, it's got to be inferior to 40 milliseconds.
Because that's really, below 30 milliseconds, one is very hesitant to talk about
these odd things, but above 40 milliseconds.
Because beyond 150 milliseconds, you see everything in good registration. It's finished.
You're now in the macro-perceptual world. It's that world between 0 and 150
milliseconds seconds, whereas there is interesting action.
And so I think it falls somewhere in that range. Okay.
But now in terms of these hierarchical relations, in some sense, what we're.
Tacitly including in this description is that, and this also goes back to Hubel
and Wiesel, is that hierarchy also implies that we integrate towards the visual
object by combining its components.
As long as we go from the details to the gestalt, to the overall person.
Do you believe that that still is a guiding principle? No.
Okay. I would say that that is only half true and therefore not true.
So the gestalt people said that a complex object is other than the sum of its parts.
So, a line is considered to be a building block of forms.
It is as if lines cannot have an independent existence of their own as forms.
It's as if a line is always going to be used to get somewhere, and that's not the case.
As the artists will tell you, many artists, from Barnett Newman,
Olga Ratanova, Kazimir and so many others, used the line as a principal element
in their paintings, and these stood in their own right as forms.
Secondly, I think that it is the assumption that it's a building block system
does not take account of the fact that there may be other—a building block system starting in V1,
which is what the assumption mainly is—that there may be other inputs which
do not go through the orientational system at all.
That maybe a face is not built up from oriented lines, although oriented lines may contribute to it.
And thirdly, I think that if you look at orientation selective cells,
you find them in V1, you find them in V2, you find them in V3, you find them in V3a.
And if you look at V3 and V2 and V3a, apart from change in receptive field between
V2 and V3 and V3a, their properties are fairly similar.
You might find differences, but they're fairly similar to at least casual observation.
Now, is it conceivable that the brain just keeps on repeating this?
Is it conceivable that the input from the LGN may not contribute to the properties
of these orientation-collective cells?
See, it's not a question that we are getting the wrong answers.
It's a question that we're not taking account of other inputs which may modulate things.
I mean, there must be a reason for having a big input from the LGN to these areas.
And it is possible that they build up orientation selectivity. In fact, they do.
Because Nikos Logosites and his colleagues in Germany showed that if you ablate
V1 completely in the macaque monkey, you still get very good orientation selective cells in V2 and V3.
Now, they are more sluggish in their response, but they are very respectable.
So it's a question of then asking, well, what role do these inputs play either in building up,
differences in the orientation profiles, or in building up different shapes completely.
But then you described one experiment where you looked explicitly,
where you used its primitive shapes to either build a house as a stimulus or a face. Yes, yes.
Right? You then compared the connection between these two classes of stimulus. Yes, yes.
And that showed that you get the input into V1,
an area specialized for faces and houses, such as the fusiform face area and
the hippocampal place area, the latencies are identical.
And the deflection in terms of strength around 50 femto-Teslas is also identical.
So now unless you posit the notion that these are supernumerary ineffectual
inputs, you have got to take into account what they do.
And there are interesting things. For example, you can get patients who are
able to recognize line drawings,
but cannot recognize the combination that these line drawings produce.
By the same time, you get patients who can recognize the photograph of a building
or something, but can't recognize the line drawing.
So, to me, the question is wide open at the moment.
But now, let's speculate a bit on that, right?
Because what's interesting here is that in this experiment where we do house
versus face detection, we actually do a tiny manipulation of the elements in
this indroid that makes a stimulus.
If you now say, okay, this is a fusiform face area, we do see a significant
response in fMRI, right? This is in humans.
How many transformations have taken place if the detection of house or face
or that distinction would happen in that area?
How many transformations, as you mentioned, have been taking place if you go
from the retina to this specific area? Okay.
The minimum number of transformations in the system that goes directly from
the LGN to these areas must be the retina plus the LGN plus one synapse.
The minimum, if you take it as being routed through V1, is of course a lot more,
because you go to V1 and V2 and V3 and then to the fusiform.
By the way, I don't think anybody has actually seen a direct input from V1 or
V2 to the fusiform face area, but I'm not so sure.
So you've got a different number of synapses.
And the typical signal for seeing faces is a negativity at 170 milliseconds
after stimulus presentation.
But this does not mean to say that you ignore the stimulus that comes at 100,
the deflection that comes at 30 to 40 milliseconds.
I mean, let us suppose that there is a certain configuration which primes the
fusiform face area, saying that this is a face, right?
Without working out the details, well, that's a very significant contribution.
What I'm objecting to is that I have not read a single paper,
I don't think, not a single paper on face physiology which does not assume that
it all starts with the orientation selective cells of V1.
Now, there's even more simple than that.
People have supposed that cells in V4, There are cells in V4 which care about curvature.
They also care about color, and they are separate from cells which are uninterested in color.
Now, nobody has shown physiologically how you transform orientation-selective
cells into curvature-detecting cells.
They have shown it computationally, which is a different matter.
But you see, so they call V4 a curvature detector.
Is this justified? I would wonder. I mean, the acceptance angles of orientation
selective cells in V4, I've measured them, and others have also done,
is much wider than the acceptance angles of orientation selective cells in V1.
And therefore, you can see that they could probably respond better to curvatures.
Ultimately, I mean, you have to, if you are going to say that,
look, it all depends upon the orientation selective cells of V1,
you must be able to demonstrate convincingly, physiologically and functionally.
And that is missing. All the rest, it's all an assumption.
Right. So would you in some sense say that the visual brain.
It's highly tuned to first respond to the gestalt of the stimulus as opposed to its detail.
I think with faces it is, yes.
And also with facial expressions. I mean, if you consider a medulla to be part
of the visible brain, which in a sense it is, I mean, it responds very rapidly to fear on a face.
And by all accounts, before you get any responses from view one.
So yes, I would say that that is the correct way probably of putting it to the
gestalt, but the gestalt being understood as being other than the sum of the parts.
Absolutely. Yes. But then the encoding of that is still a mystery.
The encoding of that is a big, big mystery, and what the further input from
V1, V2 plays in building up the final profile is also a mystery.
And no one's saying they do not contribute. but they do, but how is not known. Right.
Well, we think we have a solution to that. It's called the temporal population code.
But I can describe it to you outside of this interview, but the basic idea is
basically that if you look at volumes of cortical cells,
they perform space-to-time transformations, like you drive the cells locally,
but they're all laterally coupled. It's like throwing a stone.
No, we'll create these waves rippling through the pond. If you just take the
spatial average of those waves, you get a temporal trace.
And we have shown in this temporal trace can give you high quality,
high resolution detection of complex stimuli including phases. I see.
Okay, we can talk about this in more detail later. This is done in computational
media? Yes, in computational.
We need to look for physiological validation. But there are some hints coming
now from the optical image literature that gives us the kind of dynamic signatures
in these cortical maps that is consistent with the full concept.
So this idea of gestalt encoding, I think, is key. Nationally,
I think there are some roots into that.
But are we agreed that the Gestalt encoding is not synonymous with bringing
various bits of stimulus together?
We're agreed on that, okay. Absolutely. So we may have to jump out of standard
sequential hierarchical thinking and go back to the perceptron in the… Yes, yes.
Or the pandemonium model of self-reference, right? Yes.
So, okay, so we have an idea now of physical hierarchy.
We have a view on how this supports a plurality of functional hierarchies in
which latencies of the signal transduction feedforward or popdown can be actively regulated.
Indeed, the important consequence, as you already pointed out,
is now we have an asynchronous system that has also a highly variable expression. expression, right?
So is the asynchrony a feature or a bug?
No, it's a feature. It's a fundamental feature.
How does it help the processing? How does it help in, let's say,
the detection of a face or the emotional expression of a face or linking a name to that face?
Well, I mean, I'm not sure that asynchrony itself helps the detection of a face,
But the asynchronous perception of faces and facial expressions and colors and
motion has got an advantage to it.
You see, what is the current theory of how the visual brain works?
The visual brain used to be thought to be hierarchical, and then they're accepted.
Grudgingly at first that it was parallel, and now I think everything is combined
together and then you get a recognition.
No allowance has been made for the fact that maybe you recognize individual
attributes separately.
So the systems do not, if they're operating asynchronously, they do not wait
for each other to finish their task.
And what are the advantages of that? There are probabilistic advantages.
If you can identify an object, which let's just take three attributes,
with form, color, and motion.
If I put a gun to your head and say, identify this for me as quickly as you
can, you are at a great advantage if you can identify it by using one of the
three attributes alone without waiting for them to be combined.
If I compare you to another person also with a gun to his head,
but who has to combine all three to identify it, then he's going to be the loser.
So it is, And I suspect that this is why evolution tolerated an asynchronous
system in which one system of the brain does not wait for the other.
However, in the end, it has to come together in direction, in recognizing the face.
In the end, it all has to come together.
But in the end, what are we talking about? We're talking about the difference
between, as I say, a micro world and a macro world.
We're talking in the sub-second level.
All right so um it has
to come together and this is one of the big mysteries of how
i've compared it today to the
difference between the world of quantum mechanics and gravitational physics
these two are separate worlds how do you bring them together and i don't know
the answer to it okay but then so the one that we have these as you call these
micro perceptual domains or work,
let's talk about micro-conscious domains, right?
These will all have their intrinsic time constants, which might be modulated in some way.
And then this leads to their asynchronous
operation. How many of these micro-domains would you distinguish?
I think if you were to press me, I would say that there's almost an infinite number.
I mean, certainly ones for color, for motion, for depths, and for faces and
facial expressions, a number of different things.
I think that the, by the way, if you have two percepts which you perceive at different times.
You then are quite safe in concluding that they are processed by different groups of cells.
But the converse is not true. If you perceive two different attributes at the
same time, you cannot say they are processed by the same cell,
because they could be the same, but two groups finish their processing at a different time.
So I don't know the answer, but the answer is it could be many.
Infinite is perhaps pushing it, but it could be quite few. This has an implication, right?
Because that means that this conditional segmentation of the visual brain in,
let's say, orientation, shape, motion, color, disparity,
might be a bit of an optimistic fragmentation in just a few core domains,
while below that you might have many micro segmentations of a visual stimulus.
Yes, yes, yes, you can have, yes. Yes, I mean, if you, so you want to,
one of the functions of the brain is to gain knowledge about the world in order
to take action. Knowledge comes first.
You would grasp at any item that gives you information, so you could,
indeed, exactly as you say, you could, below that level, have a segmentation.
But a segmentation must have a functional rationale. or rationale and the functional
rationale is the identification of something,
Right. But now, would you also allow that a microdomain could combine,
let's say, color and motion?
Could that also be a microdomain, a microprocessor domain? No, that would go macro.
Okay. That would be macro for me. So it was within one of these?
Yes, yes, yes. All right.
But now, would you… But by the way, I think that there is something which is
worth saying here, which if I may just divert into art for a second.
And I don't know the solution to it, but you see, if you look at a work of art,
let us take a very complicated work of art.
Let us take the music lesson by Vermeer, something which I want to go with the
pearl earring. Everybody's familiar with that.
Now, there are certain, what you might call segments or details in that.
There's the earring, there's the mouth, there's the eyes. There are very expressive
eyes, very expressive lips and so on and so forth.
And then the earring and the forehead head and the way she looks.
But then there's the entire picture.
And the entire picture is again, in Gestalt's sense, the entire picture is other
than the sum of the parts.
And so that's what I'm trying to say.
Somebody asked me the other day in London last week.
He said, well, you know, I see no ambiguity in the music lesson.
I've painted it and I've studied it very carefully. I said, well, are you an artist?
He said, yes. And what have you studied? He studied the tablecloth, you see.
He's forgotten about the painting, which is something else. So there it is in
another example for an artistic world in which you've got segmentation and subsegmentation.
But now, to question this issue of asynchrony.
Which, of course, from a computational perspective, is massively challenging,
because we're not used to think in terms of asynchronous systems.
Yes. As you also mentioned.
Yes. So computers are strongly synchronized, and they're clocked,
and we tightly control these things.
Yes, yes. Now, you could argue that in the brain, you can,
we have some sort of a hybrid synchronous asynchronous system because we have
a lot of oscillatory patterns that seem to regulate the overall fiber rate of
neurons right typical example would be let's say this data gamma coding you
might see where tata gives you like a slow,
oscillatory response that supports some sort of selection that not everything
responds all the time but only your subset of cells that have the strongest
drive right so would would that satisfy
also your requirements of how am I going to integrate over these asynchronous.
Microproceptual... Yes.
Now, that is the most obvious way that I see at the moment. And actually,
I don't see an alternative.
Look, the fact is the binding problem has been studied for 35 years,
and nobody today, and please contradict me if I'm wrong, nobody today can tell us how binding occurs.
We don't know. so I think one
possibility is exactly as you put it that two so let's say the hippocampus and
the seter rhythms or gamma rhythms acts as a coincidence detector saying two
events occur at the same time and it's extremely interesting from this point
of view to realize that visual signals can reach the hippocampus as quickly
as they reach the visual cortex now I did not know that until quite recently,
so let us suppose that the color and the direction of motion occur within the
same theta cycle, then the brain might accept it as being highly probable that they are linked.
So that's the sort of way I'm thinking about it, but I'm not sure I've solved
it or I've demonstrated it. Of course not.
So are you in that sense suggesting that being with hippocampus is the top-level
processing structure in the visual brain?
No, I wouldn't call it top-level processing structure, but a top-level structure
which aids in processing and perception of things coming together.
At least in terms of generating, let's say, a memory-dependent painting, in this case.
Okay, so now we have a view on the visual brain, which in some sense is also
a very challenging view.
Because you have now questioned a lot of these things we thought were set in
stone almost, right? Yes, yes.
This is definitely that. It's not been easy for me either. Right, exactly.
But you came to this via the study of color.
Yes. And now color in itself is also actually way more confusing and challenging
than you might naively think it is,
because color is actually one of the first elements of perceptual processing
that really tells you where he constructs the percept. It's not given.
Is that also why you went for the study of color? Was that the main consideration?
If you want to know the history of that, it's not an uninteresting history.
I was completely dazzled by the work and the papers of Huber and Wiesel.
And they were studying primary visual cortex, as were most people.
And I liked the space to myself, so I thought I'd look at the visual association cortex.
And I thought that I would end up doing physiology to prove them right in this
endless hierarchical process.
But everything I did showed that it was a parallel processing system that looked
at different attributes.
Now, I had no idea at all that I would find something in an area which is specialized
for color. Indeed, this was heartily contested at the beginning.
But I nevertheless used stimuli of color, of motion, and form as being the three
sort of attributes I could think about, and which showed up the specialization for color.
Now, as I say, it was disputed at the beginning, but it's now confirmed.
Confirmed, but the color you see takes you into a totally different world.
First of all, the color does not exist in the world outside.
Light electromagnetic radiation has got no color. It's constructed by the brain.
But much of the study of color and color psychophysics in particular was in
fact based on the Newtonian system, that there's a relationship between between
the wavelength and composition of the light, a direct relationship,
and the color perceived.
Edwin Land came to me and convinced me that this was not the case.
And the whole system of obtaining information about the color system and the
whole way of studying it that I used since then changed.
It was no longer just reduction streams, small spots of light,
but complex natural scenes. And...
I mean, when I first described the color specialization at Oxford in 1972,
David Hubel came up to me and said, you discover the philosopher's stone.
And in a way, that is what opened up, not that comment, but the study of color
opened up for me the rest of my career in terms of my interest in philosophy
and art and things like that.
Because philosophy is the world of knowledge. I mean, many philosophers have
actually concentrated on color and of how you get information about the world in color.
And, of course, Schopenhauer wrote a book about it, you know.
And then you, it is not a big jump from that to the world of art thing.
What kind of knowledge do you get from the world of art?
So it was, it had, for me in my career, a significance beyond its demonstration
as a specialized system.
And from the point of view of physiology, I think it convinced me,
and it's convinced some, but I don't think enough people yet,
that the operations used by the brain to construct colors are vastly different
from what you would predict from the retinal mechanism. Vastly different.
That you've got huge surrounds, you've got to work out ratios,
that working out ratios is an inherited concept, that there's no appeal against it.
That cognitively, you see, I mean, if you go to Hyde Park in London at dawn
or at dusk and look at the leaves, they look green.
Although I know, because I've measured it, they reflect more red light.
Now, this knowledge does not make me see the leaves as green.
So it introduces a host of interesting issues and opens up a vast new world,
which is of enormous interest.
In your opinion, this problem of color perception is solved.
Can you say, look, we can really explain how color perception and the invariance
of color perception works?
I think we can explain it perceptually, but I don't think we can explain it physiologically.
What can we say about it physiologically? We can say that it must involve at
least two receptors which have got different spectral sensitivities,
It certainly involves the projection from the retina to the LGN to the primary
visceral cortex to V2 to V4.
That some operation takes place in V4, which compares the wavelength composition
of light coming from one area and that coming from surrounding areas to build up ratios.
That if you damage V4, you end up with a patient who's got cerebral achromatopsia,
in other words, cannot see the world in colors.
But some of these patients can actually discriminate between objects on the
basis of wavelength reflected.
Therefore, they get a completely wrong impression about the world.
That is the full stop.
How the brain implements that, how the different cells collaborate to take ratios,
etc., is not at all clear.
There's one other thing you can say about this kind of system is that hues,
as opposed to colors, the shades of color are almost strictly a function of V4.
But to do that, you require quite an elaborate system, which I don't think anyone
is yet competent enough to do.
You require to record from a multitude of cells simultaneously, single cells.
And I don't think ABT is up to the task yet. But that area is not known.
Okay. But do you think you can understand color perception reception.
Decoupled from form. Yes. Okay. Yes.
I can understand it formally in the sense that color requires a comparison.
Color is actually much simpler than form. People think form is the simplest,
but color is the simplest. In fact, people think the motion is the simplest,
but color is the simplest.
You have got four degrees of
freedom, three wave bands, but you could have two, 2, and the luminosity.
So what you do, you simply look at the wavelength composition of light coming
from one surface, or that coming from surrounding surfaces, and you work out a ratio.
That ratio never changes given a certain situation.
In other words, if I'm looking at a given scene from a given spot in Hyde Park in London,
and I'm looking at a given leaf, which is stationary,
so it's pushing it a bit, you work out, your brain works out the amount of long,
middle, and short wave light reflected from that green leaf in relation to the
amount of long, middle, and short wave light reflected from the surround.
And you can carry on looking at that at dawn and at dusk and at noon when the
wavelength composition changes all the time, but that ratio will never change.
So color is one of the prime examples of how the brain stabilizes the world
to obtain information about it.
Of course, the hue changes, the shade of color changes, but the color category does not change.
So that, I think, is fairly well evident.
So what does this mean? It means that the brain has got to compare,
simultaneously Simultaneously in time, characteristics in terms of wavelength
composition deflected from two surfaces. Memory changes.
Form is slightly different. Form, it has got to work out the relationship of
individual parts to one another,
which and then has got to work out how, if you view it from different angles
and different distances,
that maintains its constancy, which is, in fact, also the question that the
cubists, early Antical cubists, were asking.
So that becomes a much, much more difficult system. Now people have shown, actually,
that there are sometimes situations in which objects can be viewed from different
angles and lead to activity in the same part of the brain.
I think some people in America have done that. But the detailed mechanisms are still not clear.
So, here we have it, right? We have a picture of the visual brain.
It's more complex than initially thought.
But now, with that picture in mind, you then turn it all into art.
Yes. Why did you make that step?
Well, I made that step partly because I was always interested in going to art
museums and looking at things which raised questions in my mind,
partly because I also thought to myself, look, I've been paid a lot of money in grants.
And what can I say about what happens in our brains when we look at some of
the most prized things in our culture, namely works of art, which all societies have produced?
And then when I looked more into this question, I began to discover that these people are my friends.
I mean, the artists, they have been pursuing the same questions as me.
They've looked at Joseph Albers. He got it all wrong, but he asked questions
about color. as is Plato.
And the Cubists ask about form, the kinetic artists ask questions about motion,
and they reach conclusions, which we reach many years after them.
And the question of modulation of form by color, which Cézanne asked.
But then there are other things. I mean, my view is, I know that there's a definitional problem,
but my view is that all art is an abstraction, because what you do is,
for example, you take a face and you abstract an expression which then applies to all faces.
So the question is, how does an artist obtain knowledge and how does he impart it?
And it's a tremendous, tremendous talent. And, you know, there's one painting,
the One de Perea by Velazquez, when it was first exhibited in Rome in the 17th century.
Some art critics said, I have seen many paintings in this exhibition, but this alone is the.
So it spoke to him something about—it was abstract in that sense.
So if you look at the process of abstraction, the process of maintaining consciences,
these are physiological problems.
The process of modulation, the process of reduction.
When you want to represent pure movement,
as they called it—I wouldn't call it that, but that's what they called it— you
then what they did is they removed forms and they removed color and precisely
this is precisely what happens in V5 cells,
they respond to motion but are indifferent to form and to color so you know
it's profitable to the physiologist to inquire into these the artist.
Intuit if you want principles of perception what kind of principles that you
think stand out here as really having been discovered by the artists and maybe
later on being further interpreted by science?
Well, I think that there are several. One of them is the question of form constancy.
Now, the analytic cubists did not solve the problem, but nor have the physiologists,
who have taken up this problem much later.
I mean, I'm talking physiologists, not gestaltists.
The question of the modulation of form by color never occurred to us until it
was demonstrated that form and color are separately mapped in the brain.
The question of, again, the characteristics of a kinetic system never occurred.
But then there are other things. For example, it is well known,
apparently, in the artistic world that to convey the,
regardless on whose face it is, to convey a degree of haughtiness and snobbery
and indifference in 16th century Venice.
What you did was to have someone whose head is turned away, but he's looking
at you with his eyes alone.
You see, they captured this very, very well. This is a physiological fact. out.
The fact that so many people agree that this is a sign of aloofness is quite interesting.
If I may pursue this, there is another question that comes to this,
and this has now changed my life quite significantly, and that is the relationship of art and beauty.
We are often attacked because people say, well, who are you to address beauty?
What is beauty? Well, the question is we don't address what is beauty.
We address the question of what are the neural mechanisms that are engaged when
you experience beauty, which is actually a legitimate and a simple scientific
question is asking what are the neural mechanisms that are engaged when you
perceive faces or colours.
But the.
The question of beauty, I mean, it's an interesting thing,
but when you address it and you find that the experience of visual beauty and
musical beauty and moral beauty and mathematical beauty above all correlate
with activity in the same part of the brain,
then you begin, you are shaken quite a lot.
And then you put down mathematical beauty into, because mathematical beauty
was considered by Plato to be the highest form of beauty.
And he said so because he thought it gave you something about the structure
of the universe. It gave you information about the structure of the universe
because something makes sense.
Now, I put mathematical beauty in the biological category.
Now, why do I do that? Because mathematical beauty is, in a sense,
the most extreme example of the experience of beauty derived from knowledge
and learning. because only someone who is a proficient mathematician can appreciate
the beauty of a mathematical formula.
However, if you take an Indian or a Japanese or an English or a German or a
Latin American mathematician and they know the language of mathematics,
they can appreciate the beauty of a mathematical formula.
So what does it consist of? It consists of the fact that it makes sense. Oh, that makes sense.
How would it be different from the experience of beauty that a car mechanic
might have anywhere in the world when he opens an engine.
Allow me. It makes sense to the logical deductive system of the brain, all right?
Logical deductive system of the brain, and that is the same in people of different culture.
And hence it was Paul Dirac who said that when you want to judge the truthfulness
of a mathematical formula,
Don't go by its simplicity first, but go by its beauty.
And he says, and many others have told me that, I'm not a mathematician or a
physicist myself, that the theory of relativity was first accepted because of
the beauty of the mathematical formulations.
Now, you ask me how does this differ with...
With China or in Japan or UK. Well,
it differs in this sense in that the car mechanic probably has not worked out
how you design a car. He may know how it works.
But let us be clear that a car mechanic whom you confront with a problem,
which he is mystified by, but then finally solves it and is excited by,
I am sure that he also will get activation in the media over the front of the
cortex. So why do I say that?
Because what is the experience of beauty? Well, there are lots of things you
can say about it, but it certainly involves reward.
And I think the sudden illumination in looking at a car gasket also is a rewarding
experience. So I shouldn't be at all surprised.
And there come interesting questions of what is beauty?
Now you see, biologically speaking, please, because the art historians and philosophers
are terribly excited if You address the question of beauty.
But you see, moral beauty,
by which I mean that, for example, if you were to be asked, you're hungry and
you're in a scanner, you're to be asked, well, I can give you a very nice succulent steak,
but you can give it up to a hungry child. It's up to you.
If you take it to yourself, you are satisfied.
If you give it up, you are morally satisfied.
The moral satisfaction seems to connect with activity in the medial frontal cortex.
Now if you look at sorrowful beauty, which I've just done, which is by the way
a category that's not often talked about, but much of the beauty that we experience is sorrowful.
I mean, the Mass in D minor of Bach is sorrowful, the Requiem of Mozart is sorrowful,
much of Wagner is sorrowful, and many paintings of Titian, the Taking of Christ
of Caravaggio, these are all sorrowful things. You don't smile and laugh in front of them.
And that also correlates with activity in the medial orbital frontal cortex. So that, I mean, that.
Brings you back to the question raised by Plato in Timaeus.
What is beauty of the subject, of the object, length of the object,
or is it none of these, but something detached from all of them?
There's a question in philosophies of aesthetics. It's also a question for neurobiology,
but in a different way, because we want to study it neurobiologically.
They want to study it more philosophically. The other thing I want to add to
you with the farm mechanic is that, like in the domain of musical aesthetics,
first we talked about the epistemic emotion, right? It's an emotional state.
It's a feeling. Absolutely. It relates to our knowledge structure.
Yes. Yes, yes, yes. That's what we're talking about.
Now, here on the domain of music, we'd say, well, aesthetic experience in music
has everything to do with anticipation, right?
So it is, to what extent does the music I'm perceiving match or mismatch with my anticipation?
And then there you want to find some sort of balance between confirmation and surprise.
So in some sense, you could argue then that independent of the domain,
whether it's mathematics or cars, this is the commonality. The expectation.
Balancing of confirmation and surprise.
Would you go along with that? They want to define, let's say,
a static experience as an epistemic emotion that actually reflects that specific
balance between the two issues. Yes.
Confirmation, but confirmation of what? Of your prediction, of expectations.
Well, I'd like to go beyond that. I'd say that when I undertake a mathematical equation,
let me assure you I do not, but when mathematicians do, and they hit a solution
which satisfies them, they say, that's it, I've got the right solution.
So what is that? It is an expectation which is satisfied. It satisfies the brain's
logical deductive system.
Does the brain have a logical deductive system? Absolutely it does.
I mean, there's no logic in the world outside.
The whole idea about the Godel's, you see people talk about Godel's incompleteness
theorem, which is a study in mathematics.
It's nothing of the sort. It's a study of the brain's logical system and the limits.
Now, with phrases, if you, here in Barcelona, we love football,
we love ideas like Messi, who do real-time problem-solving of the highest complexity and artfulness.
And in some sense, you could also argue, well, he has to solve dynamical problems as well.
And they have their intrinsic beauty the same way as the mathematician that solves his equation.
Yes, yes, yes, yes, yes. So that means that that experience is not necessarily
a specialized logically deductive system, but a more generic problem-solving
system that defeats also action systems or perceptual systems.
Yes, but I mean, I perhaps mis-explained myself.
I'm not saying that the beauty is… we were talking about expectation.
Now, just giving you a mathematical system, it is satisfying the expectations
of a logical deductive system that will only be satisfied with this answer answer, because that is true.
But there is also, you're quite right, if you want to call it logical system,
that's fine, but the progression of action in motor activity,
which can be extremely beautiful.
I was watching with amazement the other day a replay of the goal that Pele achieved
in 1905. What a remarkable thing.
And of course, it was absolutely right in terms of logic of action.
In terms of logic of time, in terms of logic of distance, where he positions
himself, and it satisfies the viewer.
You say, my God, he's got absolutely right, and it is beautiful.
So I do not mean to say that, I mean, I think that the logical deductive system of the brain.
Is a biological system, which I think mathematicians have not understood.
It is a biological system, and there are limits to it, and Gödel demonstrated that.
But it's not the only system. Now, let me give you another example of expectation.
Expectation, I mean, when I look at a beautiful face, that also satisfies certain expectations.
And what are the expectations that I can talk about? I can say that it satisfies
the fact that the eyes and the nose and the mouth are in the correct disposition
with respect to each other,
that they are the correct proportions, that there is nothing violently against my expectation.
And then I get a man like Francis Bacon, who says, I want to give people a visible
shock. That's what he said.
My aim is to give a visible shock. What did he do? he subverted the brain's
representation of the brain and therefore the expectation.
So when you look at a Francis Bacon, you say, my God, this may have all sorts
of pain to be quoted, but that's not what the face looked like,
not mutilated like that.
So there are all these different expectations. In some of this,
this is what I was challenging you on, that I think that in the domain of aesthetics,
Aesthetics, there's always this risk to sort of disconnect it from the biology,
from real-world action.
Absolutely. In everyday life. So I was just trying to see whether you subscribe
to that or whether you see also that aesthetics as an everyday common phenomenon.
I see it as an everyday common brain phenomenon, in my view, if it is.
But don't tell that to the philosophers of aesthetics. They'll get very angry.
We will not distribute this podcast.
But then the other thing is, so if you look at art and the progression of art
and their discovery of, let's say, principles of perception and principles of experience,
if you want, way beyond where we are with our science, in which period in art
history do you think that art history has changed?
Do you think most of these discoveries were made?
Well, I think they were made at various periods. But, I mean,
let me give you one example which I'm especially interested in.
And that is the period of Michelangelo.
Now, you might say that Michelangelo made no discoveries at all.
Michelangelo did make a huge discovery, which was to represent the human body.
All right, as it should be. If you look at the drawings and paintings before
him, they don't have this power, they don't have the sensuousness,
and he did that, and he did that, by the way.
I must say this because there was an article in London two days ago saying that
people thought that Michelangelo used the golden ratio. Michelangelo never did anything of the kind.
Michelangelo said, I don't need measuring instruments because all my measuring
instruments are in my brain.
The fact is that when you come to do a great representation of the human face
or human body, the golden ratio is implicit in that.
So that is one of the great new stages.
I would say that the Cubism—well, before that, Cézanne, and now Cézanne and
the Cubists who were inspired by Suzanne, were two of the great stages.
There may be many, many others.
I think I myself, there's one of small few periods,
what he called my mature poesie, Titian, when he started drawing with his fingers,
got rid of the brush and was trying to represent motion.
It was very successful and very, very good.
But there must be many others. But now, do you feel that contemporary art,
in that sense, is more deconstructing these principles than necessarily discovering them?
I have got a very unhealthy relationship with contemporary art because,
you know, they tell me… So, I go to the Ludwig Museum in Cologne,
and I see a filing cabinet in front of me.
Now, this filing cabinet is not the filing cabinet of Bismarck.
It's not the filing cabinet of Angela Merkel.
It's a filing cabinet which could have been purchased possibly from IKEA.
And I'm supposed to be sitting there to contemplate myself in relationship to
this filing cabinet. This is not of great interest.
Whatever knowledge I may get out of it, it's not of great interest because there
are so many other things that I can do.
So I go to a room in the same museum and I see an empty white room.
So I ask the attendant, what's going on here? They don't know this is the exhibit.
So I'm supposed to be contemplating that white room.
It's not of great interest. And I really think that we should tell museum curators
that the time has come to stop.
But there are other things which I think I'm very interested in.
For example, a famous installation art, contemporary art, Tracy Emin's The Bed.
It is a depiction of a bed set.
Unmade bed, cigarettes on the floor, a bottle of gin somewhere, whatnot.
Now, I don't say this is beautiful, but it is representative of thousands of
bedsits in London and elsewhere. So, in a sense, that gives you knowledge.
And that's why I think that that is not, for me, in the same category as lots
of things which I don't admire so much.
I'll tell you an interesting story. At the Tate Gallery in London,
some German artist had an installation. And,
Part of this installation was a waste paper basket with lots of rubbish in it.
Well, the day after the thing was installed, the cleaning woman next morning
came to clean, so she emptied the waste paper basket.
She had to be told never to touch it again because of this part.
But in a sense, her action was logical.
But you are using two definitions of the impact of art.
One is an epistemic emotion or an emotional state. Another is to acquire knowledge.
But to acquire knowledge seems to be a rather weak definition,
right? Because reading a book or going to, let's say, read the manual of how
to use my telephone is also a way
to acquire knowledge, but it might not necessarily qualify as an artistic,
form of doing that. No, no, no, no.
Well, let me be more specific.
I think the function of the brain is to acquire knowledge, and art is one means,
but it's not the only means.
Let me say it's one means of acquiring knowledge. If you speak to artists,
they would say to you, yes, I acquire a great deal of knowledge about tables,
about chairs, whatever I'm doing.
And we also acquire a great deal of knowledge.
I mean, one of the, for example, the Taking of Christ by Caravaggio,
which is the National Gallery in Dublin.
It gives you a great deal of knowledge about the state of a man who knows he's
being betrayed, who accepts his betrayal, and who is in agony.
You know, it's a remarkable piece of work.
But what I was really trying, or maybe I did not say it, I don't think that
suddenly during our evolution a part of the brain developed in some people to do art.
I think art is a byproduct of the brain's knowledge-acquiring system.
You have emphasized this now several times throughout the interview, this notion of.
The acquisition of knowledge as being the key function of the brain.
And in some sense, this is a very platonic notion that was also criticized by
Dewey, for instance, who was saying, well, why for the Greek philosophers,
knowledge was actually the core objective of their philosophy,
it didn't talk about the brain necessarily, is that labor was so far removed
from their everyday existence because labor was left to the slaves.
Labor, physical activity in the work was something that was unfamiliar to them.
So therefore, for them, the highest value in life could just be to contemplate and learn.
While, and of course, Dewey was also a pragmatist, right? Well,
actually, knowledge is anchored in action.
So from that perspective, you could argue, well, isn't it fair to say that the
main purpose and function of the brain is to generate action,
but in order to do that, it needs knowledge?
Yes, I think I would go along with that. Absolutely, yes. I don't think that
knowledge is an end point in itself. I think you obtain knowledge to undertake action.
But then sometimes you cannot undertake action. But you see,
the important thing about obtaining knowledge, really, is that to obtain knowledge,
you have to stabilize the world. You cannot do it without that.
And to stabilize the world is a big, big problem. I mean, in color vision,
you can see it's a major issue. you.
But also, in a way, in these articles or work on black holes and dark matter
and dark energy and quantum gravitation,
these are all attempts to stabilize the world in order to be able to obtain knowledge about it.
Because otherwise, there are
too many signals reaching us, which I don't know what sense to make of it.
Now, I'm a platonicist or a platonic in my approach because,
in a sense, I think that Plato was right in saying that you can only obtain
knowledge about things through a thought process.
You cannot obtain this knowledge by simply looking at something.
There you obtain an opinion.
Or manipulating or experimenting with things physically. Yes,
but if you're experimenting with it, you're employing a thought process.
I don't think he thought… In fact, one of the weaknesses of Plato,
I think, is that when he talked about forms, his theory of forms,
was things like love and beauty and justice,
and he only vaguely came to the idea that a house may constitute a form.
But he did in the Republic say that if you want to obtain noise about a couch,
you cannot obtain it from a single couch. You've got to think about it.
And in a way, I think this is true. So you build up a concept unconsciously.
So I think people have dismissed Plato perhaps unnecessarily for saying that
you cannot obtain knowledge by just looking at something.
So what do you see today as the main achievements of this field of neuroaesthetics?
The field of neuroaesthetics has done quite a few things. It's only 15 years old.
So let me summarize Fourier's achievements. First of all, it has shown that
there are subjective mental states which you can study scientifically in the
sense that you can localize the activity that relate to these.
And secondly, and most importantly, you can quantify that activity and that
activity is parametrically related to the intensity of the declared experience.
But that in itself is generic. Eric, that's not specific to neuroaesthetics.
This might be also, in general, it's a perceptual task.
Well, yes, but I mean, just to have a neuroaesthetics attack these problems
first, attack the question of beauty first.
Secondly, neuroaesthetics has shown that in terms of not only of beauty,
but allied experiences, such as those of desire and love,
have the identical systems of localizable, possible, studyable, quantifiable things.
Thirdly, it has answered the question which has eluded philosophers of aesthetics
for centuries and the question was actually very well framed by Clive Bell, who was an art critic.
He said, what do all things which we experience as beautiful have in common?
Because unless they have something in common, we are gibbering.
They have never been able to ask this question, but we can ask this question,
which is that all things which we experience as beautiful have one thing in
common, though only in the neurobiological world, we cannot speak about the world outside,
which is that they correlate with activity in the same parts of the brain,
and they correlate with activity there parametrically.
Fourthly, or fifthly, it has attacked.
One of the most extraordinary problems
in philosophy and in knowledge which is the experience of mathematical beauty
and opened up a whole Pandora's box about what the experience of mathematical
beauty is and I think this is something which is going to develop more and more.
Now there are a lot of these I'm giving you the main achievement there are lots
of other things I mean it is inquiring into the role of experience in the generation of of beauty,
which is a topic that interests me less personally, because I'm interested in
what is the skeleton of the brain that is able to experience beauty, regardless of source.
It is beginning to address questions about literary beauty and beauty in dance and movement.
So they're doing quite a lot of things. But these seem to me to be the important issues.
Can you couple that from questions around consciousness? Because beauty as such must be experienced.
Absolutely. So how do you see that leak then between these epistemic static
emotions and conscious experience?
Well, I don't think you can uncouple it. I think you must address the question of consciousness.
But you see, here you go again to the sort of….
A dichotomy between quantum mechanics and gravitational physics.
The knowledge that the two are contradictory does not stop you from pursuing
good experiments in quantum mechanics, making huge advances in it,
or in gravitational physics.
Now, the knowledge that we do not have an answer to the problem of consciousness
will not inhibit us from studying the brain's esthetic system.
We just assume, we make the assumption, which is a fair assumption,
and in fact you can't proceed without making that assumption,
but you don't factor it into your experiment because it is there.
You just assume that you are experiencing something because you're conscious.
Now look at the opposite picture.
Supposing we said, oh, I cannot study esthetics, I can't study the brain system
for experiencing beauty unless I have a system of consciousness,
then you'll probably end up not solving the problem for years.
After all, what have the people who are studying consciousness,
what have they really told us about consciousness?
I think I perhaps go, I think that the important thing about consciousness is
the studies which I sort of adhere to are the ones which have shown us the minimal
conditions required for consciousness.
But I also adhere to what Stuart Sutherland once said that not a single sentence
written about consciousness is worth reading because we don't know really.
It's fashionable I know but we don't know even at what level to address it we
don't know whether it's localizable nothing I just wrote many sentences on it
actually so maybe I shouldn't have done that,
as long as you give credibility to what I've said exactly so,
How many years before you think we will have a full-fledged neurobiological
understanding of beauty?
I think I'm not really able to tell.
A full-fledged biological understanding of beauty requires, above all,
to understand something extremely, extremely difficult,
which is, is beauty a quality that's slapped onto situations,
slapped onto objects, or is it a part of these situations, intrinsically part of them?
Just as you say, is consciousness something which is slapped on the experience
of beauty, or is it part and parcel of the same thing?
So I'd be very reluctant to tell you how long it would take.
That's a question that has been with us for 2,500 years.
And probably more. And probably more. And probably more.
I documented 2,500 years ago. So take the cave paintings, right? Absolutely.
These are definitely experiments in a static experience, right? Without question.
10,000 years old. Yes, without question. So I'd be very reluctant to decipher that.
So we made quite a grand tour here. Yes. It's absolutely fantastic.
So you also have, let's say,
targeted visit touched on many issues using many different methodologies,
many different preparations to understand the brain from the sort of multi-scale perspective,
linking the quantum and the gravitational effect, if you want.
So if we would follow in an approach that you have developed,
the lines that you have set out for yourself, and now make progress on neuroaesthetics,
what would be the law, Semyon's law, that we have to adhere to?
The law? Yeah.
Well, I mean...
Such as the law of functional specialization, transported to… Would you just
get a handle on how beauty is processed by the brain, for instance?
I would say the law that I would like to be associated with me,
but actually it's associated with Edmund Burke… I derive it from… The Zeki's Law is…,
Okay, I'll tell you, Ezequiel's law is, and I'll tell you something which is
generally original to Ezequiel,
it's not found in Immanuel Kant either, that beauty can be firmly divided into
two parts, biological beauty and artifactual beauty.
That biological beauty is dependent upon inherited brain concepts,
and artifactual beauty is dependent upon acquired brain concepts.
That biological beauty being dependent upon inherited brain concepts is not easily modifiable.
In other words, you can't have somebody with one eye here and one eye here being beautiful.
Whereas, artifactual beauty is synthetic changes with time and with experience.
These are the prerequisites for studying beauty.
I think that all beauty, this is different from what Kant is saying,
all beauty must be interfaced through a brain concept,
either inherited brain concept or acquired brain concept.
The one thing which I am not really… And finally,
I can say that all experience of everything beautiful comes with activity in
one same part of the brain,
in addition to other parts but they differ between but the one big question
which I would be prepared to spend a lot of time is to address the question
of whether beauty is a separate,
faculty and entity which is slapped onto things or not,
So I've given you five laws now. Now, wait. If I want to print Zeki's law on
a T-shirt, I'm in trouble.
I need to see a big T-shirt.
So how do we compress that down into a law? Because a law has to be normative, right?
This is important now. It's a normative statement.
Something that others will have to do or will have to follow in order to make progress. is.
Beauty is a brain-generated concept which depends either on inherited or acquired concepts.
Okay, there you go. That fits on a t-shirt. That fits on a t-shirt.
The other thing is, despite Brexit, I think we will still visit this sort of
deteriorating fire across the channel. It might get better.
You never know. So three years from now, I'm going to visit your site,
step into the lab and say, okay, Samir, three years ago you gave me a prediction
and now I want to see whether you confirm it or not.
So what's the main prediction you would like to share with me today that you
will see confirmed and manifested three years from now?
You are making it very difficult. I would say that the main prediction I would
like to confirm in three years'
time is that the system of physical and mathematical beauty is entirely biological
and entirely dependent upon the brain's logical system. That's what I'd like to prove.
Okay, good. I actually would retire if I did that.
Common check. So, Samir Zeki, thank you very much for this conversation.
Thank you. Thank you very much. The CSN Podcast was produced by the Convergent
Science Network of Biometrics and Biohybrid Systems,
a project funded by the European 7th Research Framework Program.
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Music.