Translator: Michele Gianella Reviewer: Federico MINELLE
As we've all heard, many people laughed during the video.
For observing what people do and feel
is often such a strong experience, it brings us to imitate, emulate them,
they mesmerize us.
And one might wonder, however,
whether this only happens in special cases,
like the one we saw,
or rather if it is the norm,
if the psychology of others
is typically understood through these imitation mechanisms.
And it actually is a rather old-aged position.
You can see here philosophers, psychologists
who argued that psychology is mainly made
of simulation, imitation, empathy, sympathy, contagion, and so on.
But what does Neuroscience tell us today?
The most interesting finding, in this context, is a bit paradoxical,
because it doesn't come from the study of the cognitive areas of the brain,
the areas of thought,
but from the study of the motor system.
The motor system
is that part of our brain we rely on to move.
It is made of cells that, when activated, they basically cause us to move.
And by the way, if they are injured,
tragical consequences are triggered right in the production of the movement.
However, there is a small population
of nervous system cells, of motor system cells,
now widely renowned precisely as "mirror neurons",
which have a rather peculiar behaviour,
because yes, they fire when we move, as part of the motor system;
however, they also fire
when we put our hands in our pockets
and just see someone else performing exactly the same action.
So the retired man standing with his hands in his pockets,
looking at workers,
he is actually working as well, we might say.
And what are these things for?
They serve two purposes:
they basically open a two-way channel
between you and me, or between you and others.
Because replicating others' actions
is key to both understanding and learning.
I rely on it to read your behaviour,
and also to map on my motor system what you are doing,
refining in the process my motor programs.
So it's a double function.
In order to show you the first feature, let's do a little experiment:
let's pretend I'm recording one mirror neuron in your head.
So you keep your hands in your pocket,
don't move,
because otherwise the motor system will be activated,
and we will watch some videos,
so we'll see what a single one of your mirror neurons does
during observation of four daily clips.
Listening to a neuron means listening to its firing frequency,
so you will hear a crackling sound: the more the video crackles,
the more your individual mirror neuron is activating.
Let's watch the first video.
(Video)
So this is a common scene:
a person taking something, in this case an apple.
You had your hands in your pockets,
and your motor system should have remained silent.
Instead, a part of it got activated, and simulated exactly the same action.
We would expect this neuron to fire when you actually take an apple,
not when you're just watching.
Also, because they are very specific,
a slightly different action, like this one, does not work.
(Video)
No apples there, so the action was not "taking the apple",
it was something different;
therefore, that specific mirror neuron did not activate.
Other neurons surely did,
but not this one, set as it was on "taking the apple".
But the peculiar discovery is instead in the third video.
Look at what happens.
(Video)
So, what happened?
You did not see with your eyes that the apple was taken;
but you understood that, surely, someone in there was taking an apple.
The motor system, and mirror system in particular,
was warned of the thing;
so, even though visual areas have seen no apple picking,
yet we have guessed
that the picking of an apple was happening behind there,
and the motor system has joined in this understanding.
And of course, the last case, obviously, the apple is not there
and the activity of our neuron is pretty much zero.
Thus, the motor system helps us understanding other people's actions,
and not just to let us do our own actions.
By the way, the deficits of the mirror system
have been proven to cause
a bad processing of other people's actions.
So we understand others a little worse, if we have a deficit in this system.
The other side of the coin was learning:
it's involved in both understanding and learning.
And learning by imitation needs no introduction.
We all know how important it is, in order to learn something,
to try it ourselves, on one hand,
and see others doing it, on the other hand.
So it's interesting...
This image here, by the way, is an image of Meltzoff,
a psychologist who in the '70s used to stroll along maternity wards
to make newborns faces - welcoming faces, I assume -
thus discovering that children, only a few hours after birth,
were able to reply accordingly.
So, he actually showed
that already a few hours from birth we imitate, we are natural born imitators.
Now, of course,
a child has not yet a cortical development,
and of those inhibitory systems, in particular, that block this imitation.
So we can block -
If I do something like this -
now you are not actually waving your hands in response,
but in reality a part - except someone -
but a part of your motor system was actually doing that.
If you block the action, the action is not performed.
But it is programmed, as in children.
Then we learn how to block it, but this anyway leads us to learning.
So the ancient Chinese wisdom:
"If I listen I forget,
if I see I remember,
if I do I understand"
actually it's curious, because I often "do"
even when I don't do, but just watch.
Just like the guy watching the workers we talked about before.
So it is involved in both understanding and learning.
But one could say:
"Oh well, but in reality this does reduce the idea of social interaction,
because we don't limit ourselves to understand others' actions.
We must understand their actions within an emotional context,
feelings, language, communicative gestures -
so we understand all these things together."
But the interesting thing in recent years, in Neuroscience,
is the finding that, unlike what I just told you,
mirror neurons are not only in the motor system.
The architecture of the brain, of the whole brain,
implies localization of a multitude of mirror mechanisms
that are: in the motor areas
replicating, and making us simulate other people's actions,;
in emotional areas,
having us simulate other people's emotions,
or evoking them in us:
ditto for feelings, gestures, languages and so on.
So when we interact with others,
many mechanisms of imitation and simulation
are actually working at once;
and they bring us, precisely, to this kind of sharing.
An example of this can be the one linked to the cingulum area.
While the motor areas are more or less placed here,
those of motor system's mirror neurons -
the cingulum is in a deep area down here, in the prefrontal cortex;
and it does things that differ from those of the motor areas,
still partly unknown.
We know that the cingulum is activated when we, for example:
watch funny comics, comedies, one-liners like this:
"I cannot believe it, your mother is coming";
(Laughter)
during pleasant sensory experiences,
like the common everyday experience of being massaged by a Bond girl;
during the placebo effect;
and then, in this room,
everyone's cingulum got activated a little while ago
while we watched Clinton and Yeltsin in '95:
they burst out laughing at a press conference,
because the cingulum turns on
even when we observe positive expressions, cheerful people.
So we all had a shared cingulum activation,
a little while ago.
But what's the common thread of all these experiences?
To find this out,
we took advantage of cooperation, that made all the difference for us,
with Niguarda hospital, not far from here, in Milan,
which hosts Europe's main center for epilepsy surgery.
In order to map epilepsy, and treat patients,
these doctors place small electrodes inside the brain,
with a localization and functional mapping purpose;
they record patients, and fire these electrodes.
Their job, of course, is treating patients;
and they do it fabulously.
However, they collect a quantity of priceless data on the human brain,
which would be impossible to collect otherwise.
So, through this collaboration, we have tried to understand what happens
when, for example, this area is stimulated,
an area that is activated when we observe people laughing.
And now I will show you.
You will see a patient with an electrode in the cingulum -
you don't see the electrode, because it's inside the cingulum -
the patient holds her hands high, and she's asked to read.
Then, at some point,
the doctor releases a small electrical stimulus.
And this is what happens.
(Video)
So that area, activated a little while ago,
observing Clinton and Yeltsin that burst out laughing,
is not a visual area;
visual areas are elsewhere in the brain.
It is an area that triggers laughter when it's turned on.
If someone puts an electrode in this area, they have us laugh.
So the observation of that scene is directly mapped
on the areas that control our laughter,
so again, an imitation;
however, it's strong enough to make us laugh,
much like under an electrical stimulation of our cingulum.
That's why some of us laughed, during that observation.
So the mirror mechanism works, as we said, in the motor areas,
by replicating actions;
but in the cingulum, for example, by reproducing and making us simulate
laughter and other people's positive expressions,
so it's an overall mechanism.
Now, to wrap up, what's the use,
or what are the possible consequences of such a mechanism?
There are so many, and it's hard now to summarise them,
so I'll do it like this, in a moment.
Certainly, the discovery of this mechanism has revolutionized cognitive neuroscience,
there's no doubt about it.
The same is true for some areas of philosophy:
we saw how some philosophers already suspected similar mechanisms,
hence empathy and so on.
Pervasive developmental disorders:
autism has for example, among its characteristic features,
a compromised social sphere.
Then there might clearly be a connection.
And indeed, many studies are discovering that deficits in this mechanism
may have an impact on the symptoms of autism.
Rehabilitative medicine, as well:
there are some studies that show how a bed-ridden orthopedic patient
can benefit, in addition to the rehabilitation practice,
of sessions of "action observation therapy"
namely, it looks at gestures and so on.
There is an improvement.
Similar studies are done even on strokes,
where things are certainly much more complex.
Psychotherapy, aesthetics, developmental psychology and learning:
learning how to use a tool,
or learning martial arts or any other sporting ability.
All this has to do with the mirror mechanism.
So, the future will be fun.
See you later.
(Applause)