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

Bbefore 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 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 had colors on the two brains
to indicate brain areas that respond

very similarly across people.

And as you can see, this incoming sound,
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 actually 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

with 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.