[MUSIC PLAYING]
AUDREY DUSSUTOUR: If you look at any kind of animals,
I think you always ask yourselves a question-- what
is in their mind?
What they feel right now--
what they see-- were there feelings?
Do they see me?
I'm interested in the mind, and you have to look at behavior.
It's only by your reactions, the way
you moved, that you can understand
what's happening inside.
It's quite challenging when you are facing
a single-celled organism.
It doesn't have any brains.
[MUSIC PLAYING]
And I study ants and slime molds.
In a way, they're similar, because they
have a way to solve problems that
is completely decentralized.
Ants have a collective intelligence,
and slime mold do not have a brain.
So they're different than us.
So they way they solve problems fascinates me.
I'm Audrey Dussutour, and I study slime molds
because I'm interested in how organisms perceive their world.
[MUSIC PLAYING]
So I come from a big family-- lots of kids.
So my mom would always send us outside to explore the world,
because she didn't wanted us to be around, I think.
And so when you live in the countryside,
the only thing that you can play with is the environment.
So I was always collecting insects,
or I always had a lot of animals at home--
hedgehog or guinea pigs--
rabbits, whatever.
Everything I could find, I wanted to adopt it.
I still have this tendency, but my boyfriend says, no, no--
we can't have that at home.
So you always wonder how it is to be them,
and it was frustrating not to understand how they felt--
what was in their head.
[MUSIC PLAYING]
So slime mold are kind of ancient organism.
Usually, when you think about single-celled organisms,
you would imagine them to be super tiny.
[LAUGHS] But slime molds are huge.
They can be more than 10 meters square for a single cell, which
is amazing.
And what is very unique, also, for this organism-- can really
cut the slime mold into pieces, and you will
have lots of different clones.
And if you put these two clones next to each other,
they would fuse to make a big cell.
They move super slow--
like half a centimeter per hour.
So study for the slime molds-- we take pictures,
and we build timelapse.
So you have a 1 and 1/2 minute movie,
but in fact it lasts 24 hours.
[MUSIC PLAYING]
It was really by accident that I came to work on slime molds.
I wanted to see if insects could make complex decisions.
We started to a decision making experiment.
You're proposing to the slime mold
lots of different food source.
They would straightaway to the one that maximizes survival.
They would never make a mistake.
Slime molds are much better than ants,
and in fact, they are better than us--
at solving nutritional problems.
[MUSIC PLAYING]
When you start to work on slime molds,
they're for life, because suddenly, you're like,
oh my God, they're so amazing.
[LAUGHS] They're different between individuals.
So if you take a slime mold from the US,
for example-- or from Japan, or from Australia--
they would be very different.
So for example, Australian slime mold,
if you offered them two food, sometimes they'd
eat from two foods at the same time.
Japanese slime molds are more focused.
American slime molds are more difficult.
So it seems that you can kind of a personality
when you are slime mold.
You have to feed them every day, because if you don't do it,
they escape.
So yeah, I took my slime molds on holidays sometimes.
[MUSIC PLAYING]
We decided to train the slime molds, but at the beginning
we did it wrong.
Because we got inspiration from experiment in insects.
So of course, it was a complete failure,
because I didn't put myself in place of the slime mold.
I think sometimes to better understand the behavior,
you have to try to think, what is it to be of this organism?
So I stop, and I say, OK, think.
What is the slime mold doing in his environment?
You have to imagine yourself without central thinking--
without sounds.
We have a world with sights.
They have a world of smells.
If you look at slime mold, it's always going forth.
So I say, OK, what if I put something in its path
that it has to go through if he wants to eat?
And do it again and again and again
until he learns to ignore the substance.
This is called habitation-- it is
the simplest form of learning.
Slime molds-- they don't like a lot of stuff.
So they don't like caffeine.
They don't like salt. They don't like
the kind of bitter substance called quinine.
So we tried with salt, caffeine, and quinine,
and it worked each time perfectly.
With caffeine, for example, you would say, OK,
I'm going to stay here.
Taste-- no, I don't like it--
I don't like it.
Taste-- no, I don't like it.
And so then he'd go super fast.
[BUZZING AND GRINDING SOUNDS]
[MUSIC PLAYING]
So this was the first time we demonstrate
learning in a unicellular organism
by following all the criteria that were presented
by neuroscientists.
But we didn't stop there, because slime molds
have something that animals don't have.
They can fuse with each other.
So we're like, OK, can we train another slime mold by fusion?
In total, we trained more than 2,000 slime molds.
We put them together-- a naive one and habitated one--
and we let them fuse.
You see, a slime mold that has never encountered caffeine
before, and straightaway he's habituated
to ignore a substance that they don't
like-- just because he fused with another one that
was trained.
You could see that information could
go from one until four slime molds,
So it was quite an amazing discovery too.
It's not just that hey can learn,
but they can also teach others.
We discovered how slime molds habituated to salt.
It was just because it's swallowing the salt.
So we were able to inject, in fact, a memory in the slime
mold just by adding the repellent itself.
But we don't know exactly everything about that,
so we're not saying that habitation in a cat
is similar to habitation in slime mold.
It's just the behavior is the same,
but the mechanism might be different.
It's still interesting to see that cognition is not
restricted to animals.
[MUSIC PLAYING]
In French, you say, [SPEAKING FRENCH]
What is the use of slime mold?
And I hate when people ask me this question.
But you can say, OK, slime molds are
very good at taking pollutants in the environment
and keeping them.
People are using slime molds, also, to model cancer.
So there's lots of potential application for slime molds.
But I will be very honest-- it's not what drives me at all.
For me, it's more about general knowledge,
and I'm more interested in questions than,
are they useful for us?
[MUSIC PLAYING]
In fact, we're just pushing the boundaries.
Originally, we thought that cognition
evolved when the brain evolved.
In fact, it was earlier than that.
So perhaps a cell itself can be kind of a cognitive organism.
When life came about, cognition came, also.
[MUSIC PLAYING]
I face my organism with problems challenges,
and I see how they solve it.
But it always opens new questions.
Because you say, oh my God!
What did they do that?
What fascinates me-- it's being a novel type of organism very
different than us, but if you try
to think like you are this organism,
you can kind of get clues about how they perceive their world.
[MUSIC PLAYING]