This is your brain on communication

Imagine that you invented a device

that can record my memories,

my dreams, my ideas,

and transmit it to your brain.

That would be a game-changing
technology, right?

But in fact, we already
possess this device,

and it's called human
communication system

and effective storytelling.

And to understand
how this device is working,

we have to look into our brains,

and we have to formulate the question
in a slightly different manner.

Now we have to ask

how these neuron patterns in my brain

that are associated with
my memories and ideas

are transmitted into your brains.

And we think there are two factors
that enable us to communicate.

First, your brains now
is physically coupled

to the soundwave that I'm
transmitting to your brains,

and second, we developed
a common neural protocol

that enabled us to communicate.

So how do we know that?

In my lab in Princeton,

we bring people to the FMRI scanner
and we scan their brains

while they are either telling
or listening to real life stories.

And to give you a sense
of the stimulus we are using,

let me play you now 20 seconds

from a story that we used

told by a very talented storyteller,

Jim O'Grady.

(Audio) Jim O'Grady: So I'm
banging out my story and I know it's good,

and then I start to make it better --

(Laughter) --

by adding an element of embellishment.

Reporters call this "making shit up."

(Laughter)

And they recommend against
crossing that line.

But I had just seen the line crossed
between a high-powered dean

and assault with a pastry,
and I kinda liked it."

Uri Hasson: Okay, so let's look
into your brains

and see what's happening when you're
listening to these kinds of stories.

And that's not simple.

Let's start with one listener
and one brain area:

the auditory cortex that processes
the sounds that are coming from the ear.

And as you can see,
in this particular brain area,

the responses are going up and down
as the story is unfolding.

And now we can take these responses
and compare it to the responses

in other listeners in the same brain area,

and we can ask how similar
are the responses

across all these listeners.

So here you can see five listeners,

and we start to scan their brains

before the story is starting,

when they simply lying in the dark
and waiting for the story to begin.

And as you can see, the brain area
is going up and down in each one of them,

but the responses are very different

and not in sync.

However, immediately
as the story is starting,

something amazing is happening.

(Audio) JO: So I'm banging out my story,
and I know it's good,

and then I start to make it --

UH: Suddenly, you can see that
the responses in all of the subjects

lock to the story

and now they are going up and down

in a very similar way

across all listeners.

And in fact, this is exactly
what is happening now in your brains

when you listen to my sound speaking.

And we call this effect
neural entrainment.

And to explain to you
what is neural entrainment,

let me first explain
what is physical entrainment.

So we'll look and see five metronomes,

and think of these five metronomes
as five brains,

and similar to the listeners
before the story starts,

these metronomes are going to click,

but they're going to click out of phase.

(Clicking)

Now see what will happen
when I'm going to connect them together

by pressing them on
these two cylinders.

(Clicking)

Now these two cylinders start to rotate,

and this rotation vibration
is going through the wood

and going to couple
all the metronomes together,

and now listen to the click.

(Clicking)

And this is what you call
physical entrainment.

And now let's go back to the brain
and ask, so what is driving

this neural entrainment?

Is it simply the sounds
that the speaker is producing?

Or maybe it's the words.

Or maybe it's the meaning
that the speaker is trying to convey.

So to test it, we did
the following experiments.

First, we took the story
and played it backwards.

And that had many
of the auditory features,

but we moved the meaning.

And it sounds like that.

(Audio backwards)

And we flashed colors on the two brains
to indicate brain areas that respond

very similarly across people.

And as you can see, this incoming sound
induced entrainment or alignment

in all of the brains
in auditory cortexes

that processes the sounds,

but it didn't spread
deeper into the brain.

Now we can take these sounds
and build words out of it.

So if we take Jim O'Grady
and scramble the words,

we'll get a list of words.

(Word scramble)

And you can see that these words
start to induce alignment

in early language areas,
but not more than that.

And now we can take the word
and start to build sentences out of it.

(Audio) JO: And they recommend
against crossing that line.

He says, Dear Jim, good story,

nice details. Didn't she only
know about him through me?

UH: And now you can see that
the responses in all the language areas

that process the incoming language
becoming aligned

and similar across all these centers.

However, only when we use the full
engaging, coherent story

the responses spread deeper into the brain

into higher order areas

which include the frontal cortex
and the parietal cortex,

and make all of them
respond very similarly.

And we believe that these responses
in higher order areas are induced

or become similar across listeners

because of the meaning
conveyed by the speaker,

and not by words or sound.

And if we are right [??],

if I will tell you the exact same ideas

using two very different set of words,

your brain responses
will still be similar.

And to test it, we did
the following experiment in my lab.

We took the English story

and translated it to Russian.

And now you have two different sounds
and linguistic systems

that convey the exact same meaning.

And you play the English story
to the English listeners

and the Russian story
to the Russian listeners

and now we can compare
their responses across the groups.

And when we did that, we didn't
see responses that are similar

in auditory cortexes,

in language areas, because the language
and sound are very different.

However you can see that the responses
in other areas were still similar

across these two groups.

And we believe that this is because
they understood the story

in a very similar way

as we confirmed using a test
after the story ended.

And we think that this alignment
is necessary for communication.

For example, as you can tell,

I am not a native English speaker,

and I grew up with another language,

and the same might be
for many of you in the audience,

and still we can communicate.

How come? We think we can communicate
because we have this common [??]

to present meaning.

So so far, I've only talked about what's
happening in the listener's brain,

in your brain when
you're listening to talks.

But what's happening
in the speaker's brain, in my brain,

when I'm speaking to you?

To look in the speaker's brain,

we asked the speaker
to go into the scanner,

we scan his brains,

and then compare his brain responses
to the brain responses of the listeners

listening to the story.

And you have to remember that
producing speech and comprehending speech

are very different processes,

and we were asking, how similar are they?

And to our surprise, we saw
that in these complex patterns

within the listener actually came
from the speaker brain.

So production and comprehension
involve very similar processes.

And we also found
the stronger the similarity

between the listener's brain
and the speaker's brain,

the better the communication.

So I know that if you
are completely confused now,

and I do hope that this is not the case,

your brain responses
is very different than mine.

But I also know that if
you really understand me now,

then your brain and your brain
and your brain are really similar to mine.

And now, let's take all this
information together and ask,

how can we use it to transmit
a memory that I have

from my brain to your brains?

Okay, so we did the following experiment.

We let people watch
for the first time in their life

a TV episode from the BBC series
"Sherlock" while we scanned their brains.

And then we asked them
to go back to the scanner

and tell the story to another person
that never watched the movie.

So let's be specific.

Think about this exact scene

when Sherlock is entering
the cab in London

driven by the murderer he is looking for.

With me, as a viewer,

there is a specific brain patterns
in my brain when I watch it.

Now, the exact same pattern,
I can reactivate it in my brain again

by telling the world,
Sherlock, London, murderer.

And now when I'm transmitting
these words to your brains now,

you have to reconstruct it in your mind,

and in fact we see that
this pattern emerging now

in your brains.

And we were really surprised to see

that the patterns that you have
now in your brains

when I'm describing you these scenes

would be very similar
to the pattern I had

when I watched this movie
a few months ago in the scanner.

And this starts to tell you
about the mechanism

by which we can tell stories
and transmit information.

Because for example,

now you're listening really hard
and try to understand what I'm saying,

and I know that it's not easy,

but I hope that in one point
in the talk, we clicked and you got me.

And I think that in a few hours,
few days, few months,

you're going to meet someone in a party,

And then you're going to tell him
about these lectures,

and suddenly it will be as if
he is standing now here with us.

And now you can see how we
can take this mechanism

and try to transmit

memories and knowledge across people,

which is like wonderful, right?

But our ability to communicate relies

on our ability to have common ground.

Because for example,

if I'm going to use the British synonym

"hackney carriage" instead of "cab,"

I know that I'm going to be misaligned
with most of you in the audience.

And this alignment depends
not only on our ability to understand

the basic concept.

It also depends on our ability
to develop common ground

and understanding

and shared belief systems.

Because we know that in many cases,

people understand the exact
same story in very different ways.

So to test it in the lab,
we did the following experiment.

We took a story by J.D. Salinger

in which a husband

lost track of his wife
in the middle of a party

and he's calling his best friend asking,
"Did you see my wife?"

For half of the subjects, we were telling
that the wife was having

an affair with the best friend.

For the other hand, we were telling
that the wife is loyal

and the husband is very jealous.

This one sentence before the story started

was enough to make the brain responses
of all the people that believed

that the wife was having an affair

to be very similar
in these high order areas

and different than the other group.

And if one sentence is enough
to make your brain similar

to people that think like you

and very different than people
that think differently than you,

think how this effect is going
to be amplified in real life

when we are all listening
to the exact same news item

after being exposed
for days after days after days

to different media channels

like Fox News or New York Times

that give us very different
perspectives on reality.

So let me summarize.

If everything worked as planned tonight,

I used my ability to vocalize sound
to be coupled to your brains,

and I used this coupling
to transmit my brain patterns

associated with my memories
and ideas into your brains.

In this I start to reveal the hidden neural
mechanism by which we communicate.

And we know that in the future
it will enable us to improve

and facilitate communication.

But these studies also reveal

that communication relies
on a common ground,

and we have to be really worried
as a society,

if you're going to lose this common ground

then our ability to speak with people
that are slightly different than us,

because we let a few very strong
media channels

to take control over the mic

and manipulate and control
the way we all think.

And I'm not sure how to fix it,
because I'm only a scientist,

but maybe one way to do it

is to go back to the more
natural way of communication,

which is a dialogue,

in which it's not only me
speaking to you now,

but we have a more natural way of talking

in which I am speaking
and I am listening,

and together we are trying to come
to a common ground and new ideas.

Because after all,
the people we are coupled to

define who we are,

and our desire to be coupled
to another brain

is something very basic that's starting
at a very early age.

So let me finish with an example

with my own private life

that I think is a good example
of how coupling to other people

is really going to define who we are.

This my son Jonathan at a very early age.

And see how he developed
a vocal game together with my wife

only from the desire and pure joy
of being coupled to another human being.

(Vocal noise)

(Laughter)

Now, think how the ability of my son
to be coupled to us

and other people in his life is going
to shape the man he is going to become.

And think how you change on a daily basis

from the interaction and coupling
to other people in your life.

So keep being coupled to other people.

Keep spreading your ideas,

because the sum of all of us together,

coupled, is greater than our parts.

Thank you.

(Applause)