Transcriber: Deborah Oliveira Reviewer: Martina Verdún
(Applause)
Coloration and patterning are key features of our everyday lives
because we are visual creatures.
Moreover, the natural world is full of visual creatures.
Therefore, visual perception is a major part of the natural world.
That said, visual perception is not very well understood,
not only in animals, but even in humans.
Today I am going to tell a story that begins with the octopus
and talks about several aspects of vision science
with a lot of help from art
leading towards technology in the most unorthodox way.
So, let's begin right now.
To begin with, we have to pose this interesting question:
how does camouflage work?
To provide a firm basis for that, I will give you one answer.
This is Hollywood's version of how it works:
Harry Potter's invisible cloak.
But the real story is more interesting.
It is the least studied subject in Biology we think we already know about.
Everyone here probably thinks they know what camouflage is.
We are having a little trouble to figure it out.
It is quite complicated.
If you look at this image, impressionistic art takes advantage
of certain visual features you have
and gives a suggestion of what something is.
That is not one of those examples,
but watch this morph as we change it more and more.
We get to this point where we have an actual scientific image of a cuttlefish
that is camouflaged on that background.
There are all kinds of visual tricks here that I am going to talk about.
Let's go back to the camouflage.
This animal is masking its real edges, it is creating false edges with its skin,
and is doing a number of tricks that I want to talk about.
How does art inform science?
Here we have an impressionistic image that many of you have seen
but it leads us to another impressionistic image of this boring underwater scene.
There is just this fluffy rock and a fish swimming.
There is nothing happening until now.
Now you see that we had this wonderfully camouflaged octopus
that is now brilliantly white and you can't miss it.
It inks in the face and swims away.
Now it is going to do the next trick,
which is to spread its web and turn on this bright white coloration
and high contrast pattern so that gives a strong unambiguous signal.
Playing it backwards to see what happens:
smooth white skin, a ring around the eye, there are five million pigment organs
called chromatophores being enervated from the brain.
It is like electric skin.
And another 20 million are being recruited to give the pattern.
Now I draw your attention to the smooth outline of the body.
And it goes three-dimensional.
Those are some pretty good goosebumps.
The animal is now pretty hard to see even though you know where it is.
Here is beginning and here is after.
How do they do it and why?
This animal looks at this part of the algae
and more or less resembles it in the pattern, the posture,
the intensity, the color and even that three-dimensional texture.
That animal can go anywhere on the coral reef
and camouflage in seven tenths of a second.
How do they do that?
How many patterns do they need to do that?
How many patterns are there?
We have investigated this question.
We are trying to understand how it works.
We gathered thousands of images of cuttlefish and octopuses,
but how do you make something out of this mess?
We took a lot of artistic license
and tried to bin them into piles to get started.
Very unscientific.
That led to something interesting.
We had a bunch of uniform patterns we called 'little to no contrast'
because it looks the same between both ends.
On the right background, it produces some nice camouflage.
We had a 'mottled' series of patterns with small-scale light and dark.
The third pattern is quite unusual.
(Video) Narrator:
A 'disruptive' coloration
has large-scale high-contrast light and dark components,
multiple orientations and scales partly to break up the recognizable form.
But, shown here on the right background,
it also creates a fair amount of background matching.
So why three patterns?
We did a scientific analysis to prove that there are only three patterns.
It is not just artistic license.
The real question is if this is a universal phenomenon.
We looked at a lot of animals from primates to amphibians to reptiles,
all sizes, wet or dry, and you get an enormous amount of uniform coloration
as you do mottled coloration, birds and all the rest.
The real surprise is the amount of disruptive coloration.
Here is an exaggeration: a panda bear and an orca.
There is a lot of bright white coloration creating camouflage with high contrast.
The real question is 'who cares?'
With hundreds of visual systems on the planet,
it is amazing to think that a handful of pattern solutions
may create this camouflage in all size scales and habitats.
It is an elegant example of an efficient way
to create camouflage in a very diverse visual world.
Our challenge is to look for some of the highly conserved visual features
of these patterns in the contour, edge design, and so forth,
and see which visual tricks are being implemented and how.
This provocative idea is rather controversial.
That is OK because it is testable.
Let's get the art and science.
Here is the cuttlefish camouflaged and not camouflaged.
What is happening is that the animal is varying a small number of variables
such as contrast, shape and edges as you have seen.
That is what happens in many aspects of art, photography, architecture,
even makeup artists do the same sorts of tricks.
Marketers and advertisers do them as well.
Artists understand and manipulate these features better than scientists,
so we recruited artists to help us work out some of this.
I love this art by Bev Doolittle showing a pinto.
In each of those images,
she understands the concepts of how disruptive coloration works
better than most scientists do.
Here we have this beautiful Monet.
Artists can take a three-dimensional scene,
reproduce it on a two-dimensional palette
and reintroduce three dimensions.
That is what happens in this painting.
The cuttlefish has to do the same thing not to be seen
because the cuttlefish is a three-dimensional object
that has to look like a two-dimensional part of the background.
What these cuttlefish do is very clever.
They have to appear to be 2D.
We had an artist look at hundreds of this part of the edge of the real fin.
The artist was the one who showed us the recurring theme of light and dark,
concavity and convexity that makes that edge disappear into the background.
It is this sort of feature that helps us move along.
I teach occasionally at Rhode Island School of Design
and gave the students a test to do a 3D object on a 2D background.
This student took it to the hilt.
That is the student. Here she is.
Only an art director would film sideways like that.
I liked that.
Even the patterns on it were very well done.
I hope she got an A for this.
We are now bringing an artist to work with us and do some of the science.
Designers do the same thing.
You can either make a house that is conspicuous
or one that fits into the background.
You can design a building downtown that looks like this
or you can even put green plants on it.
You can have a building like this one that stands out
and you can paint it differently and have it blend into the background.
This is what the cuttlefish does here, only it does it very swiftly
by looking at the background and quickly figuring out what features are important.
Part of the idea is that designing patterns with nature in mind
has got a lot of mileage and hasn't been done.
Biophilia is a wonderful concept promoted by E. O. Wilson
that articulates this very well.
Back to the animals, we have many patterns and fast change.
I want to illustrate if we can pull something out from the animals
and go towards technology.
Watch this cuttlefish moving along.
It looks like a Prius changing color driving down the road.
It even has landing gear.
Look at the skin and how dynamically changeable it is.
How is it doing this?
With the available light.
Here is a pattern that is easy to see.
It goes down, settles on the bottom,
and within a few milliseconds decides 'here is how I camouflage myself.'
Now it goes back up and you see all this craziness in the skin.
Watch what happens next.
The animals can look like this and this.
Actually this is one of the more boring species.
Other species have greater repertoires than that.
How do they do it?
I already gave the idea that they use this wonderful eye
to look at the background and decide how to look.
But I want to talk about the skin,
because that is where the mileage is in terms of changeability.
Here we have a yellow, a red and a brown chromatophore.
When these muscles attached pull out, they open it into a disc of color.
When some are pulled out and others are not, you create a pattern.
But patterns alone are not good enough.
You also need reflectors underneath to give the other blues, greens and pinks.
You also have a white base layer in the skin of these animals.
This is where their secret is.
We have a three-layered system: pigments at the top,
reflectors in the middle, and a white base layer on the bottom.
A piece of light might come in, go through three of these pigments and go back out.
Another stray of light might hit no pigments, hit the reflector and go off.
Another streak can go through one of the reflectors,
hit the white and go out.
There are lots of combinations to change the appearance of the animal.
The interactions of pigments' reflectors are part of the secret.
I want to point out that animals are using pigments and reflectors
with available light, whether a lot of or a little light,
and are creating patterns just as good as this one.
This is the route to inspire these novel synthetic materials.
Here are real chromatophores working in real life on the left.
Our colleagues are beginning to make materials based on the same concept
of no pigment and pigments expanded out by various methods.
The ultimate challenge would be to do this:
look at the skin morphing like the octopus at the beginning.
There is presently no material known that can change that sort of dimension,
especially in the air.
To finalize, this odd road has taken us from Hollywood
to the real animals doing something, uncovering a very unexpected finding
that there are only three basic pattern types for camouflage,
using artists and working with them to clarify some of these ideas,
applying it to animals and buildings to see how the visual effects change,
finally looking at the skin itself and towards better display technologies.
Nature's sophistication holds treasures and ideas that have yet to be realized.
That science benefits from technology is very obvious,
but I think it can benefit from art.
And conversely science could contribute to those two areas in the same way.
I would like to finalize with this sign hanging at the library here in the MBL.
[Study nature, not books.]
It has been there for 120 years.
I think there is something to it and it is my excuse to go diving.
Thank you very much.