Original subtitles

Freeman: Our minds store our entire lives...

Our memories, our talents, our deepest desires.

Tell no one, and our thoughts remain our own.

But that might be about to change.

Our brains are biological computers,

vulnerable to data theft.

Computer hackers can read our e-mail.

Brain hackers may someday read our minds...

And even rewrite our thoughts.

Can our minds be hacked?

Space, time, life itself.

The secrets of the cosmos lie through the wormhole.

Subtital By RA_One

we live in a world of data.

We all know how vital it is

to protect our personal information,

our passwords and credit-card numbers,

but what if hackers learned to read or tamper with

our most precious and private store of data...

The contents of our minds?

Can the brain be hacked by a computer?

The data in our brain is not stored as simple ones and zeros.

Hacking into our thoughts

requires decoding the logic of our neurons.

Science is getting close to achieving that goal.

One day soon,

our innermost thoughts may no longer be our own.

I once tried to hide the truth from my mother.

I lied,

but when she looked into my eyes,

I knew that she knew.

How could she know?

Man: How you doing?

Please turn off your cellphones.

Now put your hands together for the one and only Marc Salem.

Enjoy the show.

[ Cheers and applause ]

It's only me.

Good evening, everybody. I'm delighted to be here.

What I'd like to do is choose somebody at random...

Freeman: Marc Salem is one of new.

York's most prominent psychologists,

but he also has a remarkable talent,

one that has catapulted him into show business.

All right, here's what I want you to do.

I want you to say "Stop" At any point.

Say "Stop" At any point.

Woman: Stop. Okay.

Look at the first word on the first line.

Have you got it? Yeah.

Okay. Hold onto this.

All right. Say nothing at all to me.

Say nothing at all to me. Just think of the first letter.

A, b, c, d, e, f, g, h, I, j, k, I, m, n, o, p,

q, r, s, t, u, v, w, x, y, z.

Okay. It's an "S." Is that correct?

- Yes. - Okay, good.

Let's see. The second letter, probably a vowel.

A, e, I, o, u. A, e, I, o, u.

- It's an "E, " Isn't it? - Yes.

Freeman: Marc's mind-reading ability is not magic.

He's reading tiny physical clues

his subjects are unwittingly giving him.

Se..."E."

- the word is "Second"? - Yes.

Give her a round of applause, please.

What I'm looking for, first of all,

is some kind of difference

in the way that they're expressing themselves.

Should I get rid of this one or this one?

- That one. - Get rid of this one.

I think every mental thought that we have

has some physical corresponding emission.

There's something that we can tell about that thought.

We literally can see people thinking.

My friends, let me just say once again,

nothing that I did this evening is supernatural.

Nothing that I do is occult.

Thank you so very much.

[ Applause ]

Freeman: From his stage shows and from his academic research,

Marc has learned

that it's almost impossible to keep a secret.

What our brains are thinking

can't help but leak out into our physical bodies.

Now, this light board is really somewhat like your brain

in a simplistic form.

We have impulses traveling out interdependently.

That is, each relies on the other one.

Freeman: Just as your brain

controls every muscle in your body,

our theater light board

sends signals to every light in the house,

and just as the light board

operates groups of lights with a single command,

so does the brain.

For example, Clarissa, show what would happen

if we switched switch number one.

A single button triggers a complex set of actions.

Lights turn on. Lights turn off.

Others move or change color all at once.

In the same way, when we think a thought,

our brains trigger a whole set of movements in our bodies.

Let's say suddenly,

it occurred to the person that they look ridiculous.

Hit number two, please.

Suddenly, that thought would change,

and the physical would also change.

Perhaps a sly smile would come on someone's face.

Psychologists like Marc

call these involuntary muscle reactions information leakage.

He believes there's no way to stop it,

even if you have the perfect poker face.

Hi, guys. I'm glad you're here.

I know that you're, among other things, gamblers,

and we're gonna try a little bit of an experiment

with how you think

and information you may be giving off...

What sometimes you may call tells...

What we're really looking at as nonverbal communication.

Could everybody look at their card, please?

Remember it and put it down.

To play a game of poker,

you need to prevent everyone at the table

from guessing your cards,

but Marc believes he can see through any player,

no matter how blank their expression may be.

Let's try you.

Think red, black.

Focus on it. Black, red, black, red.

Black, black, black. Red, red.

I think it's definitely black. Is that correct?

- Yes. - Okay.

Spades, clubs, spades, clubs.

Okay, there's a rapid blinking, discomfort at the spades,

so is it a spade?

Okay.

Ace, 2, 3, 4, 5, 6, 7, 8, 9, 10.

Jack, queen, king.

There was a very tight blink on the Jack,

so I would think Jack.

Salem: There are ways to know what people are thinking.

You have to learn to pay attention

to the subtle differences, the subtle nuances,

and that's what I do.

I try to look at what's normally done

and then what those subtle nuances are

and plus what are universal.

Freeman: Natural mind readers like Marc

can decipher thoughts from involuntary muscle movements,

but cutting-edge technology

could give brain hackers direct access to our thoughts,

even if our muscles never move.

Augie nieto is a fitness industry entrepreneur.

In 2005, he was diagnosed with a.L.S.

And soon became almost completely paralyzed.

The only parts of his body he can move are his feet.

He uses them to control a speech computer.

Even these muscles will eventually degenerate,

but he may not lose the ability to communicate.

Neurotechnology pioneer Dr. Philip low

is hoping to hack into augie's mind before it's too late.

Philip and a team of engineers

are building a state-of-the-art brain reader,

a device they call the ibrain.

I'm wearing the first portable brain monitor ever built,

and what it is doing is it is recording my brain data.

It is actually sending it over to our servers,

and our algorithms can crunch it.

Freeman: Every time we decide to move our muscles,

billions of neurons fire miniature bolts of electricity

inside our brains.

Philip's electrically sensitive ibrain

can detect these electrical pulses

by measuring the small changes in voltage

they produce on the surface of the scalp.

By seeing the activation of particles of brain structures,

we can tell, "Oh, this person is trying to move his hands."

Freeman: Philip thought the ibrain

might help patients like augie

who, despite their paralysis,

have healthy, functioning brains

that can still send signals to their muscles.

A.L.S. Patients do not have problems

when it comes to their own brains.

The areas that his brain is using

in order to control these limbs,

these areas are still working perfectly fine.

They're just unemployed right now.

Hi, augie. Nice to see you again.

Freeman: If the ibrain

can pick up augie's mental intention to move,

Philip could create a new means for him to communicate.

You will have a prompt.

It will ask you to imagine to, you know, move your right hand

for four seconds at a time,

and, of course, we're going to be monitoring your brain waves

very, very closely during that time

and having all of our algorithms crunch the data

in the background, as well.

The test is successful.

Philip's ibrain recognizes

whenever augie is thinking about moving his right or left hand.

Low: Augie had a very successful first test.

We will use these brain patterns

in order to control a virtual hand on the screen,

which will enable him to just pick these words

and pick these letters and enable him to communicate,

so this gives us a lot of hope and encouragement

that, in fact, we have a system that will work for everybody

and that will enable individuals to use their brain patterns

in order to communicate.

Man: The biggest fear for someone with a.L.S.

Is to be not able to communicate.

That is called being locked in.

With the ibrain, I will never, never be locked in!

Freeman: Soon, augie may not even

have to think about moving his hand

in order to communicate

because a laboratory in California

has already begun to translate thoughts

into pictures and words.

We all have thoughts we'd rather keep to ourselves.

When computer scientists want to keep something secret,

they encrypt it,

but it's just a matter of time before any code is cracked.

The electrical activity buzzing

between the neurons in our brains

could be the next code we decipher.

In fact, some neuroscientists

are already translating the language of the brain

into plain English.

Neuroscientist Jack gallant is on a mission

to translate the flurry of activity inside our heads

into plain English.

You might say he's writing the book on it.

Gallant: You can think of each part of the brain

as translating between the world

and whatever the brain activity is in that part of the brain,

so there's some sort of language you can think of

that's gonna mediate between the world and the brain,

and if you had a list of all of the things

that related the world to the brain,

you would essentially have a dictionary.

Freeman: The first brain

dictionary Jack set out to build

was for the language of sight.

There are about 50 or 70 brain areas

that are devoted to vision,

so there's gonna be, essentially,

50 or 70 different dictionaries

that we're gonna have to build...

One dictionary for each region of the brain.

Now, that's gonna be a really big dictionary.

It's gonna be much thicker than this

because the number of things you can see in the world

is really, really a large number.

Freeman: To build a brain dictionary,

Jack and his colleagues shinji nishimoto and Alex huth

use an fmri scanner to measure exactly how the brain responds

to a long series of video clips.

So, this is a viewer that allows us

to visualize the blood flow while the movie plays.

Blue means relatively less blood flow,

and red means relatively more blood flow,

and you can see

that the blood flow's changing quite dramatically

as the scenes in this movie play,

and the problem that we have in modeling the brain

is to try to understand what the relationship is

between each individual point in this brain and these movies.

Freeman: But as they compiled thousands of scans of brains

reacting to thousands of frames of video,

Jack and his team found that certain objects

trigger predictable patterns of blood flow,

and they began to build

a dictionary of objects in the world,

defined as particular patterns of blood flow in the brain.

Gallant: And then once we have this world-brain dictionary,

we can actually take it,

and we can sort of run it backwards,

and we can create a brain-world dictionary.

Freeman: To test that dictionary,

they send their test subjects back into the fmri

to watch more movies,

except this time, they don't see what the subject sees.

Jack and his team have to guess using only the raw data

from the brain scans and an advanced computer algorithm.

So, there are probably, say,

10,000 points on the brain, 5,000,

that are being used in this model,

and each point in the brain has a predicted brain activity

that it generates when you stick an image through it,

and then we aggregate information

across all those 10,000 points

to come up with the best prediction.

Freeman: This is the image that only the subject could see.

These are the top choices the computer selects

from the brain-world dictionary,

and this is the composite average.

No matter what the subject sees in the world,

the brain-world dictionary can produce a rough copy.

But this algorithm does more

than just guess what images people are watching.

It can also guess what they are thinking about those images.

Here on the left is the movie that the subjects saw,

and on the right, you can see 2,000 nouns and verbs,

and they change their size,

and the size of the word indicates the probability

that that concept appeared in the video at that time.

You can see here, it gets "Talk, "

"Face, " "Woman, " "Man."

here, "Talking, " "Man."

you'll see, here's "Hand, " "Room, " "Face."

so, this is a complicated scene.

Here we go. We switch to an ocean scene.

"Clouds, " "Sky, " "Vegetation" "Waikiki, "

"Body of water, " "Building, "

"Sky, " "People walking, " "Tree."

these are all really very accurate semantic decodings.

Freeman: Jack's team has built

a dictionary of 2,000 emotionally neutral concepts

that people might think

when they watch their series of videos.

Calibrating their computers to decode more personal meaning

is only a matter of time

and increasing the level of detail in the brain scans.

We're constantly surprised

by how much information we can recover,

especially given

that the measurements we're taking of the brain

are still, at this point, really, really primitive.

That's one thing that I think is really exciting about this field

and really interesting,

and I also think it raises a caution flag

that I think we're gonna have to deal with these ethical issues

involving brain decoding sooner rather than later,

because we don't know

how fast this technology's gonna progress,

and that opens up a big ethical can of worms.

You know, when is that gonna be used?

And what can it be used for?

And I really think this needs to get addressed right away.

Freeman: Brain hackers may soon be

able to read your every thought.

What then?

If your thoughts can be decoded, could they be altered?

This neuroscientist and entrepreneur

is pushing the boundaries of brain manipulation

with a device

that could turn amateurs into experts in a single day.

We'd all love to be truly great at something...

Maybe a physicist like Einstein

or an artist like Picasso

or a great leader like Nelson mandela.

Most of us have to settle

for simply good instead of incredible,

but what if we could change that by hacking our mental software

and giving ourselves capabilities

we weren't born with?

Chris berka is a neuroscientist, engineer, inventor,

and c.E.O. Of a neurotech startup company.

It's a workload that would crush most of us,

but she handles it by getting into

a high-performance, high-output brain state.

It's what athletes call "The zone."

berka: Being in the zone,

it's essentially just focused attention

and the ability to not be distracted.

It's what allows you to really develop perfection in any skill.

Freeman: Getting into the zone is

a full-time obsession for Chris.

Her company is developing a device

that she claims can train your brain

to work like the brain of a highly-skilled expert.

Chris oosterlinck

is a California state archery champion.

Berka: He has a small band around his head

that has four sensors

for sensing the brain's electrical activity.

We're gonna be looking for the particular state

leading up to the shot

that we know is the peak performance state.

So, Chris, do you want to get ready and go?

Freeman: Inside Chris' brain, billions of neurons are firing,

creating waves of electricity.

Different states of mind have different frequencies of waves.

When people are in the zone, two frequencies dominate...

Alpha waves,

which indicate a state of meditative concentration,

like those of a zen master,

and lower-frequency theta waves, which show extreme relaxation.

Berka: The red line indicates the e.E.G. Theta activity,

and the green line indicates the Alpha activity,

and we see both of those Alpha and theta increase

just prior to taking the perfect shot.

Freeman: Chris brings in a group of amateurs.

She wants to see what will happen

if she coaxes the amateurs to take their shots

while in the same brain state as a professional archer.

Berka: So, what we're doing is

monitoring the brain's electrical activity.

We do that by putting sensors on the scalp,

and as you move through

different cognitive states and mental states,

the electronic frequencies of your brain will change,

and we can record those in real time and analyze them.

Freeman: Each amateur focuses and relaxes to reach the zone.

Chris' monitor records their brain waves,

and a small haptic buzzer on their collar

lets them know when they've achieved

the same brain state as the professional.

We're seeing the e.E.G. Alpha increase and theta increase.

The haptic buzzer stopped,

and now he's ready to take the perfect shot.

Go ahead, Shane.

That was perfect. [ Chuckles ] That was perfect.

That's exactly the goal.

Freeman: By the end of only one day of practice,

Chris' technology hacked the minds of a group of amateurs

to shoot at or close to a professional level of expertise.

Berka: And what we're able to demonstrate

is a 230% increase in the speed and accuracy

of marksmanship training.

Freeman: Chris sees no end of potential customers

for her brain-hacking device...

A corporate board that needs to make smart group decisions,

a president who needs peak performance,

or a special-forces operative whose split-second choices

make the difference between life and death.

What we're trying to do is to give you the ability

to control your mind and your mental state,

your ability to deal with

even the most challenging environments,

and just by training you to control your brain,

you get this kind of metacognitive awareness

that allows you to be much more resilient

and adaptable to stressful situations.

If we can hack into our own brains to amplify our talents,

what's stopping us from hacking into the brains of other people?

Could one mind reprogram the reality of another?

Let's do an experiment.

Close your eyes.

Keep them closed.

Now imagine you're alone in the desert

and your throat and mouth are swollen with thirst.

Now think about drinking a cool glass of water.

Open your eyes.

Do you feel refreshed?

If you do,

I just hacked into your mind and altered your perception.

Stanford's David spiegel is not your typical psychiatrist.

He helps his patients overcome their struggles

through a technique that is controversial

for a university doctor...

Hypnosis.

Hypnosis is a form of highly focused attention

coupled with an ability to dissociate,

or put outside of conscious awareness,

things that would ordinarily be in consciousness

and a heightened response to social cues or suggestibility.

And hypnosis is highly focused attention.

It's been called believed-in imagination.

Freeman: David wanted to know

how people perceived the world when hypnotized,

so he has designed an experiment to look at the brains of people

who have the ability to hypnotize themselves.

Okay, Katie, you doing all right?

Katie: Yep.

- Good. - All right, now,

we're gonna go into a state of self-hypnosis now.

Uh-huh.

So now I want your eyes to be relaxed and closed,

and imagine your body floating somewhere safe and comfortable,

like a bath, a lake, a hot tub, or just floating in space.

Each breath deeper and easier.

Body floating safe and comfortable.

Once she is under hypnosis,

David shows Katie a grid of colors.

What colors do you see now? Just name a few.

Good.

Katie perceives the color grid,

and her fusiform gyrus lights up.

This part of the brain becomes active whenever we see color.

But because Katie's under hypnosis,

David can now tamper with her senses.

And now I want you to drain the color

from the image in front of you

so that what you start to see is just gray, white, and black.

Just drain away the color.

Now again, remaining in this state of concentration, Katie,

please tell me what the image looks like to you now.

- Good. - Yeah.

Physically, the color image has not changed,

but David now takes another scan of Katie's fusiform gyrus.

Spiegel: So, we're looking now

at the regions of the brain

that actually light up,

because there's more blood flow when they're looking at color

than when they're looking at black and white.

Here is what the blood flow was

when they were really looking at color,

and here's the blood flow when they were looking at color

but drained it of color and saw it as black and white.

Freeman: Even though she's still looking at a color image,

the blood flow to Katie's fusiform gyrus is decreasing.

It is proof that her brain

is turning off her ability to see color

at David's suggestion.

The image she perceives is becoming black and white.

David believes that hypnosis opened up Katie's brain

for reprogramming.

His thoughts hacked into her mind

and became her real living experience.

We tend to think that the brain processes raw information

and we make sense of it afterwards,

but it turns out,

especially in studies of hypnosis,

that we can reset the brain,

that we can change the way

the brain actually perceives information,

so it's not that it reacts differently to the same input.

It changes what the input is.

Freeman: David's work suggests that while under hypnosis,

the way our brains perceive reality is altered.

I had a student who was doing research with me on hypnosis

who is also a really talented athlete for the football team.

He was terrific, and he was very hypnotizable,

and I would say to him,

"So, what's going on when you're playing like this?"

he said, "Doc, when I'm having a good day,

I'm aware of two things.

I'm aware of the football and the defender."

[ crowd cheering ]

And he said, "And there's 20 other big guys on the field.

I don't know they're there.

There's 60,000 people yelling at me from the stands.

I don't hear them."

clearly, our minds are programmable.

We have hardware that allows us to take in input, process it,

and do something with it,

and that input can come from ourself

or from people around us.

Freeman: Hypnotism opens our minds to brain hackers,

but we have to make a conscious choice

to enter a hypnotic state,

like a computer that can accept or reject

another user logging on.

There may be a hole in our neurological security, however.

A team of researchers in Tel Aviv

claims to have found an exploit

that could open our unconscious mind to hackers.

Freeman: Think back to your childhood.

What do you recall?

Your mother's perfume?

Fresh-cut grass?

Oatmeal cookies baking in the oven?

A familiar scent can flood the mind

with images, memories, and emotions

whether we like it or not.

Computer hackers write programs called cracks

to break into secure systems.

Could your sense of smell be a crack for a brain hacker?

Ilana hairston is a research psychologist

in Tel Aviv, Israel.

Ilana is fascinated by what happens in our brains

when we sleep.

It began with an experiment she did in her student days.

Hairston: At the time, I was working with animals,

and I could see that I would train animals on a maze

and they would not learn.

"Clearly, " I thought, "These animals are very stupid, "

and then I'd go back, put them in the cage,

come back the next day, and boom,

they performed like they'd been practicing the whole night,

and it just blew my mind.

It made me realize we spend a third of our life asleep,

and there's so much going on while we sleep.

Freeman: Ilana thinks that our

minds must be able to learn

when we lose consciousness.

To prove it, she's plotting to break into the sleeping mind.

It's a job that requires her to first get past

the brain's night watchman, the thalamus.

Hairston: There's a part of the brain called the thalamus.

What it typically does,

it's gonna clamp down on sensory information

and stop you from waking up,

or if it says, "Okay, this is important information.

You need to wake up, " It'll cause you to wake up.

Freeman: But Ilana believes there

is a back door into the brain

when we sleep...

Our sense of smell.

Smell goes first to the cortex...

And so it kind of bypasses this relay station.

Basically, you can enter the sleeping brain

without going through this relay station.

Freeman: When we fall asleep,

the thalamus acts like a watchful nanny.

Our senses try to deliver information to the brain

but are turned away.

Input from our sense of smell, however,

has direct access,

and once inside,

sensory signals that are normally tuned out

during our sleep

can be snuck in.

Ilana teamed up with research partners

at the weizmann institute

to hack into the minds of sleeping test subjects

using odors.

They hook a test subject up to a machine

that can produce a wide variety of sense

and then measure how deeply the subject breathes.

The subject falls into a deep sleep,

and Ilana and her colleague go to work.

They release a pleasant perfume

and immediately play a high-pitched tone.

[ High-pitched tone plays ]

Later, they release the smell of rotting fish...

And play a low-pitched tone.

[ Low-pitched tone plays ]

The process repeats throughout the night until morning arrives.

Hairston: So, we just got our participant out of bed,

and he's not hearing or smelling anything,

and we're gonna present the tones alone without the smells

to see if he responds to the tones.

So, now we're just watching him breathing.

Freeman: The subject had no conscious awareness

of the odors presented throughout the night

and has no memory of them now,

but Ilana wants to see

if his breathing patterns reveal

an unconscious, visceral reaction

to the high and low tones.

She first plays the tone linked to the perfume.

[ High-pitched tone plays ]

The inhale was much bigger and wider

compared to his normal inhales.

We paired this tone with a pleasant odor.

Then she plays the low-pitched tone,

the one that was paired with the foul stench.

[ Low-pitched tone plays ]

Again, you can see the trigger of the tone,

and he's literally holding his breath.

The subject does not smell anything,

but his mind reacts as though he does.

He associates the high-pitched tone

with pleasant, breathable air

and the low-pitched tone with foul, nauseating odors.

The key issue here

is also that he doesn't actually remember anything

that happened during the night.

He's not actually aware that this tone was associated

with a bad smell or a good smell.

He's just responding to the tone

without any knowledge of what we expect him to do.

Ilana believes that this brain-hacking technique

can be refined and used to manipulate any unconscious mind.

Hairston: And then the question is

can we do this with a more subtle paradigm,

like training people during sleep?

And I think the answer would be "Yes."

Freeman: Take, for example, politics.

Your support of one candidate

might seem, to you, to be unswervable.

But while you are sleeping,

scent hackers could train your mind

to associate pleasant or foul odors

with just about any sound,

even the sound of a particular person's voice.

The next time you hear that voice,

your newly-learned subconscious reaction

could turn adulation into disgust.

Hairston: Because odors are emotional,

I think we could modify our emotional responses to stimuli,

so I think you could modify emotional responses

and thereby modify behavior.

Freeman: Someday,

how we react to anything in the world around us

could be manipulated by a brain hacker.

It's a future that may come sooner than you think,

because this scientist

is already building the ultimate brain hack.

His technology could put any thought into our heads

with a flash of light.

Today, we can manipulate human brains

by tampering with the senses, bathing the brain in chemicals,

or by playing psychological mind games.

But all these methods influence the brain from the outside in.

A true mind hack,

one that opens us up for reprogramming of any kind,

may require something more audacious...

Reaching inside a living brain and flicking a switch.

M.I.T. Engineer, physicist, and neuroscientist ed boyden

has spent his career figuring out how complex machines work.

He's now working on the most complex machine of all...

The human brain.

A cubic millimeter of brain tissue has 100,000 cells,

and there are a billion connections between them.

These cells compute using electricity,

and if all these little electrical computers

could be recorded, perturbed, controlled, and analyzed,

then maybe we could understand how the brain computed it

in the same way that computers

are engineered to do all the things that they do

and our phones and on the Internet and so on.

So, if you have a complex system,

whether it's a computer or a city or the economy or a brain,

one of the ways that you can figure out what's going on

is to actually put little inputs into the system

and see what happens.

Freeman: It's easy to test the

components on a computer circuit board,

but brain cells are a little trickier,

so ed set out to find a natural switch

that can turn individual neurons on or off,

and he found one swimming around in a puddle of pond water.

Boyden: This kind of algae actually has this light sensor.

It sits in a little eye spot in the back of the algae,

and basically, these are little light-activated proteins

known as opsins

that sit in the membranes of cells

and serve as photosynthetic or photosensory protein,

and this is a molecule that converts light

into a very specific change in electrical potential,

the exact same kind that occurs in neurons when they're active.

Freeman: Ed and his colleagues extracted from the algae

the genetic code that produces these light-sensitive opsins.

They then inserted this gene into a virus

that could splice itself into the DNA of living brain cells.

Boyden: The neurons in the brain will manufacture the protein

because now the genome has been incorporated

into the nucleus of other cells

and then expressed those proteins all over the membranes,

or boundaries, of those cells.

Freeman: Ed's virus instructs any infected neurons

to build a light-sensitive on/off switch.

With these switches, any brain circuit

from our senses to our emotional state and memories

could be controlled with this.

Boyden: So, this is a laser that we developed here,

which will then split that laser light

out into an array of optical fibers

that we can enter information into the brain

into many different points

that are distributed in a three-dimensional pattern.

The brain doesn't feel pain,

so we can implant little probes into the brain,

deliver light out the end of these probes,

and then we'll turn on or off parts of the brain

just by pulsing this laser,

turning the laser on and off very rapidly.

Freeman: Ed and his colleagues

first put that technology to trial

with animal subjects.

Ed wired his light-sensitive switches

into a mouse's pleasure-reward brain circuits.

We put in an optical fiber into the brain

such that it could deliver light to those cells.

Then we programmed a computer such that

whenever a mouse hooked its nose into a little sensor,

it would get a pulse of light.

Freeman: Each pulse of blue light

activates the same pleasure-reward circuits

that turn on when the rodent eats a piece of food

or finds a mate.

The mouse keeps poking its head into the hole,

convinced that this simple action

is the source of the reward.

Boyden: And so, what we found

was that mice would actually work for light.

They would poke their nose in the little sensor,

get a pulse of light, say, "Hey, that was interesting, "

and then do it over and over again,

basically doing a task in order to get a pulse of light.

And so what this tells us is

that very brief activation of this set of cells

with a pulse of light

is enough to reinforce whatever the animal was doing

just before.

Freeman: Ed has hacked the mind of a mouse

and changed its behavior,

and he believes it won't be long

before we are ready to use the technique on the human brain.

Boyden: Arguably, humans have been hacking the brain

for a very long time, you know.

Beer, coffee...

Those are examples of neurotechnologies

that their main role is to change what the brain does.

Drugs, pharmaceuticals have been very, very impactful

in treating brain disorders,

but if you think about the brain as a circuit,

then a drug that goes throughout the entire brain

is gonna affect circuits that you want to leave intact,

as well as circuits that you want to fix,

and that's where our technologies come into play.

We really can make a subset of those cells

activatable or silenceable with our tools.

Freeman: Ed's technology could be a

cure for the nearly 1 billion people

who suffer from mental illness

by turning off only unhealthy cells.

It would be a revolution in psychiatric medicine,

and one day, it could give us all

complete control of the workings of our brains.

The rewards for hacking into our brains could be momentous.

Mental diseases could be eliminated.

We could unlock the highest levels of talent,

and we could truly understand what another person feels.

But there is a dark side to this technology.

We could be creating a future

where no one is sure of who they are,

no secrets could ever be safe,

and where we might all lose our minds to brain hackers.