Translator: Eddy Carbet Reviewer: Elisabeth Buffard
How does our brain generate thought, consciousness?
How does matter produce subjective experience?
For a long time, this has remained an exclusively philosophical question.
It has become now a major scientific question.
Because, thanks to these new technologies,
we have the means to measure what's happening in that brain.
So I'm holding my own brain right here, in my hands,
It's a 3D reconstruction,
a 3D print of my grey matter, obtained by MRI.
It's tens of billions of neurons,
thousands of billions of connections:
that's more than the actual number of stars in our Galaxy.
Some say, it's the most complex,
the most complicated thing known to Mankind.
With one exception...
the woman's brain.
(Laughter)
Seriously, I'd like to share with you some of our research
on patients with severe damage to the brain,
who are in a coma.
And for those who survive coma,
sometimes, there are some incredible stories,
near-death experiences,
those patients that tell us they left their very own body,
that they saw the light,
that they had the experience
of an extraordinary well-being feeling,
and so, this is also an appeal for witnesses.
So if someone here has had such a near-death experience,
or know someone who has,
let them share it with us.
We now have over 200 accounts of near-death experience,
at Liège University,
and that's important
Because extraordinary phenomenons
need extraordinary evidence.
To understand better and convince
the medical and scientific community,
that ignored this phenomenon for too long,
which for some is seen as a proof of life after death.
And, besides listening to those stories,
we can watch what's happening in our brains.
Various techniques.
Here you have an example,
where we can measure energy consumption:
we inject some sugar, glucose, marked with a radioactive isotope,
then we can see grey matter activity.
You can see a sectional view with yellow and red colors,
these neurons are the most energy consuming cells,
compared to all the other cells,
and next to them you can see the sign of an empty box,
it's what happens in case of cerebral death.
Only the few cells surrounding the skull, inside the skin,
are still consuming energy,
but those neurons don't anymore.
Here, you can trustfully donate your organs.
Because if there is any scientific of life after death,
it's called organ donation.
(Applause)
It's really different from what we can actually see
in these patients who are about to survive coma.
And who will sometime awake,
but without showing any sign of consciousness:
That's what we call a vegetative state.
I find this term too pejorative,
we now prefer to talk about non-responsive awakening.
Because this is what we see:
They're awaken, their eyes are wide open, but they don't respond to simple orders.
and this is our conscience test.
So what we ask ourselves is,
what consciousness in this coma
or after this coma,
in a vegetative or non-responding state?
Now we have tools,
that we call brain-computer interfaces
Where we can, you see here,
electrodes on scalp,
more than 250, that will measure the electric activity of the brain,
and then we'll ask one question again, like:
"Move the foot",
but we don't look at the foot anymore,
we look at what's happening in the brain.
I'll take my own brain again,
- having two of them is handy -
When I move my hand or I want to,
there is a region in the grey matter, right here, that will activate itself.
And I can see it with the EEG.
And when I move -- sorry -- my hand, it's going to activate right here,
When I move the foot,
we'll see the activation closer to the center.
So, this allow us not only
to see that the patient is not unconscious,
that he respond to the command,
but also to establish a communication,
at least with some of them, we have to admit,
a minority of the patients,
that can't speak anymore by definition,
cannot hum...
move, control their muscles after a coma.
There are other means, like here, trying to communicate with eyes :
It turns out that when you make an effort,
like mental calculation,
your pupil is going to dilate.
So I can ask you an important question:
where does it hurt?
This possibility of perceiving pain is really important,
and has direct consequences
with our care..
So how does it work?
We ask the question,
we show a "yes"
and you've got to calculate mentally
at the moment of seeing the "yes",
that'll lead to pupil dilatation:
we can see it.
In this case, we can't see anything.
That's when we show the "no"
that the camera will detect that the pupil is dilating,
so we can deduce that the patient communicates us a "no".
Again, without moving any muscle.
But there is a big problem here.
The patient must understand the question.
If he is aphasic and doesn't even understand language,
what can we do?
So we developed some other techniques..
Measuring brain activity at rest.
Actually, the brain never rests.
It thinks.
It thinks all the time,
and we can try to visualize these thoughts.
So, as you can see, I'm taking my brain again,
I'm going to open it, and inside this brain,
you have a network, we can call it "self-consciousness network"
so if you're thinking right now
about your past, about planning your future,
this little voice that talks to you inside,
you're about to activate a network:
here at the front,
and here at the back.
In this brain depth,
it's the network of self-consciousness,
that you can see in yellow
and that in some patients,
considered in an pseudo-coma, the locked-in syndrome,
they are conscious patients, completely paralyzed,
unable to speak,
or classically, only
with little winks
that we can establish a communication,
and at first it's really difficult,
whereas functionnal MRI, as you can see,
is going to show
these yellow regions, this activity, this network of self-consciousness,
with a was that is really easy to identify,
but we have to be careful.
Sometimes pictures can lie.
The brain doesn't produce any consciousness
just like the kidney produces urine.
There are a lot of things that we still don't understand.
So we have to be cautious.
And if it is actually difficult to quantify consciousness,
to reduce it to a figure,
or to quantify pain,
it's also really difficult
to quantify the quality of life.
Nevertherless, it has to be at the center of our interests
So I would like, here, with you right now,
to try and get an answer to this difficult question:
How are you?
We're going to calibrate our own scale for the quality of life.
So I'll ask you to identify
the best moment of your life.
Beside this TEDx.
That's plus 5.
And then the worst moment of your life.
your divorce, or your marriage: minus 5
If you've actually done that,
I can now ask you the question:
In the past two weeks,
on a scale from minus 5 to plus 5,
where are you at?
Well we asked this same question to a locked-up syndrome patient.
You can't be more incapacited than that,
they're dependent on the others
for all daily tasks,
and here is the answer.
The majority says that they have a life that's worth living.
Don't judge a book by its cover.
So you can see there is a minority here,
that says they aren't happy,
a bad quality of life.
We even asked the question about euthanasia,
where there is a minority of patients,
that want to die.
And... Contrary to Belgium,
in France, we didn't have a law that would allow it.
So to conclude,
I think these new technologies,
functional MRI, brain-computer interface,
allow us, not only to be more precise in diagnostics,
but sometimes they can even allow us to establish communication
with non-speaking patients.
They showed that we have underestimated the capacity of consciousness ,
to have a kind of consciousness during and after coma,
to sometimes underestimate the quality of life of some patients.
And next to this medical and ethical interests,
there is also a scientific interest
where we are pushing boudaries further,
demystifying that remaining big mystery, that is human consciousness
So I may have two main messages for you:
That's first, to think about the interest of identifying
a trusted person,
to establish a will an anticipated statement,
just in case,
and it can happen to any of us,
after an accident, a head trauma, a heart attack,
you fall into a coma.
It's the right time to communicate your will
you should do it, anticipate.
And second point, you should think about the benefits of organ donations.
Thank you.
(Applause)