All language subtitles for The.UnXplained.S02E02.1080p.WEB.h264-ROBOTS

‐with his ears.

A deaf man who hears

with his eyes.

And a man who lives in a world

completely devoid of pain.

Sight, sound,

taste, touch and smell.

These five senses
are what we humans use

to perceive the world around us.

We tend to think
we understand them pretty well.

After all,
we use them every day.

But what about people
whose abilities

are so acutely developed,

they challenge everything
we know about our minds,

our bodies,
and even reality itself.

Well, that is what
we'll try and find out.

THE UNXPLAINED - SEASON 2
EP - 10 - Superhuman Senses

Professional swordsman
Isao Machii

is about to perform
an incredible demonstration.

He will attempt
to cut a baseball,

traveling at a hundred miles
per hour,

perfectly in half,

and from a distance
of only 30 feet away.

It seems impossible.

That is...

until he does it.

When I first saw

the video of the samurai cutting
the ball in half,

I was absolutely amazed.

What I like about video
these days

is you can do
some simple physics.

You know, he's maybe
sort of 30 feet away,

the ball is roughly
a hundred miles an hour,

and that gives you
a reaction time

of essentially .2 seconds,
in this case.

Typical reaction times for
a really elite baseball player

trying to hit a fastball
tend to be around .4 seconds.

Actually, this is
a more difficult task

than something like baseball
pitching, because clearly,

with baseball pitching,
you pick up information

from the body shape
of the pitcher,

which tells you loosely

when the ball
is going to be released.

Whereas in this instance,

he seems to have a wall
in front of him.

There's a lot of uncertainty

in terms of when the ball
will begin its flight.

And the fact that he can do
all these things

in 200 milliseconds
is obviously quite amazing.

In this

and in numerous
other demonstrations,

Machii has shown
a remarkable ability

to visually track
fast‐moving objects

with an acuity
that few can even dream of.

But how?

Perhaps the answer can be found
by examining the history

of a man who can "see"
the world around him

just as well as, or even better,

than most people,

despite the fact
that he doesn't have eyes.

Two‐year‐old Daniel Kish,

just one year after having both
eyes removed due to cancer,

sneaks out of his crib

to explore
his family's backyard.

Far from being fearful
or afraid,

Daniel is as confident
as he is curious,

because, at just two years old,

he has developed an ability
called echolocation,

which allows him to see
by using his ears.

For those of us
that study sensory systems,

Daniel Kish is a rock star.

He is clearly
the most studied human

that actively echolocates.

So he will emit sounds himself.

These sounds will go
and bounce off objects

and come back to his own ears,

and these noises
provide him information on...

distance to a target, what
that target might actually be,

how dense it is,
how light it might be,

its shape.

I've been able to echolocate
for as long as I can remember,

and for me
it was as natural as breathing.

It was just my way of seeing.

I didn't really know
it was echolocation per se.

I just knew that I was aware
of my surroundings

and that I could function
with that awareness.

It was just sort of part of
the process of learning to see,

which is very much
what sighted kids actually do

as they begin
to calibrate their vision.

After that,
it was just sort of normal.

It was just a matter of course
to click and scan

and find things

and to not really be afraid
of what was out there.

For most of us,

if you've ever had any
experience with echolocation,

it's probably
when you've been told

about how bats work, right?

Bats emit a sound.

The sound bounces off objects
and then comes back to them.

So they can actually determine
how far away an object is,

what its size and shape may be,
and so forth.

And what Daniel's done is,
he's taken this idea

and, uh, basically, uh,
turned it into something

that humans can actually use.

Without ultrasonic hearing,

without all of the advantages
that bats have evolved,

humans are somehow able
to do this,

and relatively easily.

So... how? Why?

I believe that we can do this
because we always have.

We've been doing it since man
was prey and not predator,

since we had to hide
in the dark.

So we don't have to develop
these systems from scratch.

All we have to do
is turn them on.

By making clicking sounds

and then listening
to how those sounds reverberate

off what's around him,

Daniel is able to create
a virtual picture

of his surroundings
with astonishing accuracy.

Neurobiologically,

I think this speaks to something

that we call
sensory substitution.

That his visual cortex has been
appropriated, if you like,

because it's not receiving
visual information.

Daniel's rare abilities

made him the world's foremost
echolocator.

But there are some
in the scientific community

who question the extraordinary
nature of Daniel's ability.

They argue that it's more likely

that Daniel's simply making
lucky guesses

when he claims to sense
his environment.

But for Daniel,
there's no question.

He sees a map in his mind.

And what's more...

‐ ‐he can prove it.

Even though he's never seen,

he's clearly using
his echolocation skills

to construct some sort of map
of the visual world,

although he doesn't have
any experience

with the visual world the way
someone that's sighted does.

When I visit a new place,

I basically just look around.

And for me, that involves,
of course,

using my sense of echolocation

to scope out the environment.

I start out
with what's most distinctive,

what stands out,
uh, what's most unique,

uh, what seems to define
the space.

Essentially, it resolves into
what I call three‐dimensional,

fuzzy geometry.

So all of these features

sort of coalesce
into an actual image.

Mapping it is part
of the process.

Drawing is a way of sharing

what my relationship
with the environment is.

It's a way of...

giving people a peek
into my head.

So, you've got a house here.

That's
the most relevant feature.

There's a parked vehicle
of some kind there.

And, then, trees.

And then,
just as I got to about here,

I was able immediately to tell,

okay, this has got to be
some sort of a patio area,

or maybe a grotto.

And then, as I rounded the area,

this tree line became
very obvious,

that bounds one edge
of the garden.

Daniel often says that,
you know,

he can see these things
in his mind,

and skeptics would say,
"Oh, that's impossible,

"he must be hearing sounds
or just making calculations

and guesses
that just happen to be true."

But he's actually able
to prove it.

He's actually able to draw
what he sees in his mind.

And it's accurate.

I am a person
who is naturally curious.

I've been an explorer
since I got out of my crib

and started wandering around.

It didn't really occur to me
that, "Oh, but wait,

I no longer have eyes."

My interest is
in understanding the world,

knowing about the world,

and sharing whatever it is

I think I've learned
about the world with others,

to the extent that others
may benefit from that.

It's not about seeing
or not seeing.

It's about knowing.

It's about understanding,
and it's about sharing.

Daniel's incredible ability

to make his way
through the world

is truly a sight to behold.

But how did he develop
such an unusual

and powerful sensory ability?

Perhaps a clue can be found

by examining a group of people

who can literally hear
the world around them

in color.

We sense the world

where color has a sound,

and where sound has a taste.

If that all seems bizarre,

well, then imagine
what it must be like

to live in that world

every day of your life.

Tofino, British Columbia,
August 1998.

55‐year‐old Carol Steen
and her husband

are hiking along the shores
of the Pacific.

It's a day like any other.

That is, until Carol takes
one wrong step.

There were all these
black boulders, they were huge,

and we were kind of
crawling around on them.

My husband, being athletic,

decided that he
would jump off this rock.

I did the same thing.

And I did something very bad
to my knee.

I ruptured the ACL.

Tearing an ACL is
a traumatic injury,

even for professional athletes.

And yet, for Carol,
the first thing she experienced

wasn't a sensation of pain

but one of color.

I didn't feel pain.

Instead, everything
that I saw was orange,

and this was with my eyes open.

The sand was a lighter shade
of orange.

The ocean was another shade
of orange,

and the blur of orange
was my husband,

and he said,
"I'll get you up on some rocks,

and I'll go get help."

It may seem odd,

but this is just one example
of Carol's senses mixing

that she has dealt with
for years.

And it's an extraordinarily
rare condition

that scientists refer
to as synesthesia.

Synesthesia is often described

as an unusual union
of the senses.

Perceptions that we tend
to have separate‐‐

like sounds versus sights
versus touches versus smells‐‐

get sort of combined
in ways that are unusual.

They've identified
at least 70 different forms

of synesthesia.

The common forms would be people

who can hear color
and see sound.

There are two ways that we can
perceive these joined senses.

90% of us see it
in our mind's eye,

and that's the same place
where you watch your daydreams.

And ten percent of us

see it actually projected
out there in front of us.

Hearing color?

- ‐Seeing sound?
- ‐

What a marvelously
strange ability.

And yet, it's something
that almost all of us do,

although
to a much lesser extent.

We're all synesthetes.

There are cross‐connections

going on in all of us, except

we're not consciously aware
of them.

And so, what makes
synesthetes different is

that they simply have
more cross‐connections

than you or I do,

and they are also
consciously aware

that they have them.

In extreme cases of synesthesia,

a person,
like Mississippi native

Lidell Simpson, for example,

can be born deaf and yet

somehow still be able
to hear sounds.

Lidell is hearing the same way
that you and I do.

It's just
that his auditory cortex

is being stimulated
not through the eardrum

but through other senses.

It's like, well, suppose
a blind person said to you,

"Oh, you poor thing.
Everywhere you look,

"you're always seeing things.

Doesn't it drive you crazy
having to see everything?"

And of course not, because

seeing is the normal texture
of our reality.

Synesthetes simply have
a different texture of reality

and different point of view.

Lidell is a fantastic example
of brain plasticity.

I mean, when you think about
an individual that's deaf

and has this large region
of the brain

that's no longer
processing sound,

the fact
that these other modalities

have basically set up camp

in what would normally be
his auditory cortex

is really phenomenal.

In most instances
of synesthesia,

there's some mixing
of the senses,

but it doesn't necessarily
involve all the senses.

For Lidell, he seems

to conjure this rich,
very complex auditory scene

out of all the things
that he encounters.

When we think about people
with synesthesia,

um, I think one of the reasons

why people with normal sensory
systems find them so interesting

is because they're clearly
having experiences

that we'll never have.

And trying to understand how
they're experiencing the world

through somebody else's
eyes and ears

is always really interesting
to think about.

Synesthesia shows
that we sense the world

in a much more integrated way
than we think we do.

Synesthesia reminds us

of the brain's
extraordinary ability

to process data
in a most unconventional way.

Such is the case of one man

whose sensory condition sounds
like a dream

but can, at times,

be a nightmare.

Pain38‐year‐old Steven Peteharm:

attends to his Sunday chores,
like yard work

and cooking and tinkering

with several projects
in his basement.

All the same things that any
person might do on a weekend.

But for Steven, he has to do
all this far more carefully

than the average person,
because for him,

doing household chores is more
than just a series of tasks.

It's actually dangerous.

I was born

with a rare genetic condition
called congenital analgesia.

At the time,
that was the name given to it.

Now it's called congenital
insensitivity to pain.

So, uh, I can't feel any pain
at all.

A life free of pain?

Sounds like something
many of us would pay dearly for.

But for people like Steven,

death or severe injury lurks

around every corner.

My parents first noticed

something was different
when I was teething

and I chewed off half my tongue.

That definitely alarmed them to,
uh, something serious going on,

so they took me
to my pediatrician,

who, uh, did a couple of tests
and determined

that, more than likely,
I didn't feel pain.

They ran needles
up and down my spine,

uh, poked my feet
a couple places.

I still didn't elicit a negative
response, a painful response.

Steven's gruesome injury
provides a stark reminder

that while most people probably
don't think of pain as a sense,

it may actually be

the important sense of all.

Congenital analgesia is

an inherited form
of insensitivity to pain.

"Congenital" means
it runs in the family,

and "analgesia" means
that you don't feel pain.

You have no feeling of pain
whatsoever.

It's some form of mutation
in a gene

that's essential
for pain perception.

When people first hear
that I don't feel pain,

they think it is the greatest
thing in the whole world.

They're like,
"Wow, you got a superpower."

But my childhood was
spending good chunks of time

in the hospital.

I'd stay anywhere
between, like, four months

to maybe a year and a half,
which isn't normal.

It's an extremely
problematic condition.

Pain protects us from self‐harm,

and it's often the first sign
of disease.

So people who are pain‐free
often die very young.

It's actually rather amazing

that he's made it

through life as far as he has.

I mean, the classic example

we would always hear about
is learning

not to touch things
that are hot.

Pain alerts us when we're doing
something in the external world

that doesn't make sense
and we should stop.

The one thing that
I really have to keep an eye on

is probably whenever I'm engaged

in, like, a physical activity
that's a little bit strenuous,

like doing yard work.

It's stuff like that,
where I could injure myself

and not immediately realize it,

that could cause serious
repercussions down the road.

When we think about senses,

we always think
about the classic five senses:

sight, touch,

smell, taste and hearing.

One thing that's
really interesting, though,

is, we basically have
another sense,

which is our pain,
our sense of pain.

We often just reject that as,
well, that's just touch.

But that negates
or doesn't think

about the internal pains
we often feel,

whether it's headaches
or stomachaches

or sore muscles,
which really isn't quite touch.

Pain is another sense.

It's a sense
that we call nociception.

It's conveyed
by specific kinds of nerves

that get activated when,
for instance,

we might touch a hot stove
or cut ourselves.

What's interesting is,

the brain can regulate pain
dramatically,

but the basic drive
that causes pain

is from the peripheral nerves.

The nerves that send information
into the brain

don't work in congenital
analgesia patients.

This loss of pain is caused
by malfunctions

in a very small number of genes
that are extremely rare.

One of them is involved
in signaling

in the peripheral nerves.

It's called Nav1.7.

It's a protein that's called
a sodium channel.

It's like an electrical switch.

And if that protein
doesn't function properly,

then you can become pain‐free.

Since Steven doesn't feel pain,

it begs the question:

what does he feel instead?

It's difficult for me to try
to explain, but even though

I don't feel physical pain,
what I can feel is

heat, cold,

touch,
just like every other person.

What I do feel is probably
a byproduct of pain,

is, like, these impulses,
almost like a nerve firing.

Since 2012,

I have had the opportunity
to be able to participate

in a couple studies
with different universities.

I spent a good portion
of my childhood in the hospital,

and during those stays

it was usually
with people who felt pain,

and seeing people,

especially that young,
who are going

through such painful
experiences,

um, that's really what
prompted me to sign up

for a lot of these studies
when I was approached.

And the overall goal
in a lot of these studies is

to try to create
a nonnarcotic painkiller,

because the opioid crisis
that our country is facing

is one that other nations
are facing as well.

So I've been asked quite a lot,

with all these studies
I've been participating in,

if I had the chance
to feel pain,

if they could figure out
what activates

or deactivates that switch,

would I myself want
to feel pain?

Um, and my answer is just no.

Um, and that's only because
I've damaged my body so much

throughout my entire life that,

if I were to feel pain
right now,

I'd just be in a constant state
of pain all the time.

Not only do I have a bad knee,

uh, but my back is
a little bit messed up,

so my quality of life

would just be low,

and there's no way
I could live like that.

Pain.

As devastating as it can be,
it is clearly one of the senses

we shouldn't be so eager
to live without.

But if our sense of pain
can be diminished,

might it be possible
for our other senses

to be enhanced?

Perhaps the answer can be found

by examining the story
of a young man

whose musical abilities
could be said to rival those

of a Beethoven.

He was only five years old,
and already

is in the middle of a lesson,

when a blind five‐year‐old boy
bursts through the door

and changes Adam's life forever.

I first met Derek 35 years ago.

And this totally blind
little boy

was desperate
to get at the piano.

And he just pushed us
out of the way and got playing.

And I thought,

"God, he's mad."

You know, there were notes
flying everywhere.

But he was playing
"Don't Cry for Me, Argentina,"

but with lots of scales
and arpeggios and chords.

And I suddenly thought, wow,

you know, he's not mad,
he's a genius.

When I first tried
to teach Derek,

it turned out he could just play
any tune that I named.

He was only five years old,
and already in his head

he clearly had thousands
of songs already memorized.

Derek was born very premature,

and he had to have a lot
of oxygen to keep him alive.

And we know
from modern neuroscience

that doing that to a brain
causes it to grow

in a slightly different way,

to wire itself up
in a different way.

The thing with teaching
autistic children like Derek

is to form a relationship
with them.

He's got to trust you.

He's almost got to love you,
really, as a little boy.

It's almost like
a parent‐child relationship.

So he'll trust you to take him
into new territories

that he doesn't necessarily feel
comfortable with.

It's got to be
a human relationship.

He's making it up as he went
along. That's terrific.

Brilliant!

What a great gift
and what a, what a great talent,

and it's something for you
to be very proud of.

Derek Paravicini.

Over the next 35 years,

Adam worked closely with Derek
to hone his natural abilities.

The result...

Derek is not only a world‐
renowned professional pianist

but someone
whom scientists believe

may be among a rare group
of humans

who possess the most finely
developed sense of hearing

in the world.

Ah!

‐Well done, Derek.
‐Yay. Thank you.

The whole
of Derek's musical ability

is really founded on one thing,

which is that his hearing
is so acute,

he can hear
tiny differences in notes

that most people can't.

And Derek can remember them
as well.

Derek, shall we play
our copy game?

We'll play our copy game,
please, Adam.

Perfect pitch is really rare
amongst people as a whole.

Probably about one in 10,000
people have perfect pitch.

But Derek has
kind of perfect pitch‐plus.

Play this note,
exactly as it is. Ready?

‐ ‐

So I can play one note,
say F‐sharp,

and Derek instantly hears it.

You know exactly which one
it is, don't you?

‐I do.
‐What if I play two notes?

But there's more to it
than that,

'cause if he hears two notes,

or three notes, even ten notes,

‐all at the same time...
‐Four notes.

Instantly, Derek can hear it.

Uh, seven notes.

In fact,
we've done tests with him,

and he can hear ten notes.

And he processes them
in less than half a second.

Yeah.

Every day I sit down and we
start to play, and I think,

"How did you do that?"
And that, to me,

is what keeps it interesting,
because

musicians give me a window
into the brain that's unique.

We have developed
tools and research

to try to infer about what
happens in someone's brain.

But I have personally
been involved

in measuring Derek's ability,

and I can very confidently say

that I have exhausted
our technological means

to actually try to develop

a test that could measure
Derek's ability.

Some people say
that Derek's abilities

are almost superhuman,
but I would say

that it's much more
sophisticated than that.

Not only can he unpack tens,

dozens, hundreds of pitches;

he can make
musical sense of them,

and that's something
that only Derek can do.

I have not come across any piece
of technology that can do that.

While Derek has set a new bar

for hearing aptitude,

it appears
that his heightened sense

is not without its downsides.

Because, as superhuman
as Derek's hearing is,

the rest of his mind seems
to have paid a price.

‐Yay! ‐Well done, Derek!

‐You enjoy that?
‐Yay. Enjoyed that, Adam!

‐Yay! Good session?
‐Good session.

The thing with Derek's
abilities, they come at a cost.

They come at a cost
of understanding language,

of being able to sustain himself
independently,

being able
to function independently.

Derek is almost like
Alice in the looking glass.

Everything is reversed.

So really complicated things

that most people
would find impossible,

like a whole piece of music,

go straight
into his long‐term memory.

Really easy things, like "what
did you have for lunch today,"

just don't stick.

And that's the extraordinary
enigma of Derek.

But what is it

that gives Derek
his extraordinary ability?

Is it simply his means of
compensating for his blindness?

Or is there something more
to it than that?

When we think about these cases,

an obvious place to go is,
oh, he's blind,

so it's the lack of eyesight
that is contributing to this.

What I don't know, and I think
people are still looking at is,

is that something that happens

sort of early on
in the formation of the brain

that's purely a function of, oh,

the eyesight isn't
really being connected?

Or is it a process
that happens more over time?

Understanding what
that connection is, I think,

is a very deep
and interesting question.

I think, when you consider
individuals that have

a severely impaired sense,
like blindness or deafness,

they're gonna have
a very different reality

than people that have
more or less intact senses.

But don't think of it in terms
just of the loss,

but the fact that they're
gonna have amplifications

in their remaining
intact senses.

The great thing about Derek

is Derek the person.

He's so much more
than a clever musician.

Derek is above all
a people person.

So he makes his music
for people.

He'll remember people he meets

in terms
of the pieces they like.

He may not remember the name,

but he'll remember
a particular piece of music

they asked for,
even ten or 20 years later.

Derek's gifts,
while remarkable, remind us

that enhanced abilities
of all kinds

often come at a cost.

But is that always the case,
or is it possible

for us to unlock an unlimited
number of sensory abilities

that we have within us?

Even those
we don't even know we have?

Scientist Cornelia Fermuller

publishes a study
about how optical illusions

expose a fundamental flaw
in our brain.

Even when we know
our senses are being tricked,

like when we look
at an optical illusion,

we are powerless
to do anything about it.

And the truth is, our eyes
are deceiving us all the time.

For me it's not so surprising

that it's easy to fool our
brains with optical illusions.

Our brains are not designed
to reflect reality as it is.

They're designed
to make the best use

of these ambiguous
sensory signals.

We all have
an experiential reality.

We'll see
a three‐dimensional world

with objects
and colors and shapes,

we'll hear sounds,

we'll taste things,

we'll feel things,

and that's our
experiential reality.

Now, most of us tend to think

that our experiential reality is
giving us a pretty clean map

of what
the objective reality is.

But the probability that we have
been shaped by evolution

to have our experiential reality
match any aspect

of the objective reality
is precisely zero.

Instead, what evolution has done

is given us a bunch of hacks
so that you can survive.

We're not tuned to the truth.

We have simple tricks and hacks.

Put your blindfolds on
for me, please.

A group of scientists
have gathered to perform

an intriguing experiment
designed to find out

whether children have
sensory abilities beyond those

we already know.

These particular children

seem to be able to do something
that is unimaginable.

Somehow, they can both read
and identify objects

while wearing a blindfold.

Teacup.

We came across
a group of children

who were able to read
completely blindfolded.

Of course, in the beginning,

we said, "This is a trick.
It's impossible."

The visual system works
with light.

But when we were working
with these children, you could

literally give them a book that
they have never read before,

and they would put
the blindfolds on,

and eventually they could see.

"Our day out is ruined.

"No mouse would put a paw out

in what‐‐ that weather."

Somebody from the outside

looking in would say,

"What's going on here?
This is impossible."

But if that's possible, then

what other abilities
might we have

that we're not even
aware of yet?

Tell me what
I'm holding in my hand.

A wooden spoon.

So, we wanted
to investigate this phenomenon.

In 2018,

we started to work
with this Russian group.

We worked
with a couple of scientists,

and they introduced a device
inside the mask,

uh, that measured the number of
light photons inside the mask.

Once the device showed
that there was no light

whatsoever inside the mask,

then we started the test.

We also measured the brain waves
of the subject.

And we could see
that the person could see.

They could read
as if they were seeing normally

without any mask
or anything whatsoever.

Forty‐two.

This is extraordinary.

How do you even begin
to explain that?

How indeed?

Because these subjects seemingly
were able to sense things

without using any
of their five senses.

So, then what explains it?

Of course, everyone recognizes
the five senses

that we all have.

However, it seems

that we are also able
to have another sense,

another way
to receive information,

retrieve data
from the physical world

beyond the five senses
that we all know of.

If you take a look
at the animal kingdom,

they have six,
seven senses as well.

Bees, for example,

can see ultraviolet radiation.

Birds are famous for being able
to lock onto magnetism.

So if animals have other senses,
then why can't we?

It all sounds a bit
too ooga‐booga, doesn't it?

Well, not according to a study
published by scientists

from Caltech in 2019,

which suggests that humans can
not only detect energy fields;

they can also sense
the magnetic field of the Earth.

The human brain
has a lot of phenomena

going on inside it that uses
electromagnetic charges

and electric fields.

And if you change the magnetic
field around your brain,

it will impact what's going on
inside your brain.

So, small magnetic fields are
most certainly detectable.

We just may not realize
we're detecting them.

It wouldn't surprise me
in any way

if there aren't aspects
of, uh, brain function

that we are completely
unaware of at the moment,

that we'll become aware of later

when we understand more about
how the brain actually works.

Since it's already been proven

that humans have more
than five senses,

could there really be something
to the notion

that we have the potential
to sense the world around us

in what some would consider
bizarre or even mystical ways?

According to some researchers,
the answer is yes.

And as evidence they point

to an incredible phenomenon
known as paroptic vision.

Paroptic vision
was first proposed

by a surrealist writer
called Rene Daumal,

who, as a teenager, practiced

seeing color
through his fingertips.

So he'd put different colored
handkerchiefs inside a box

and then he'd run tests to see

if he could tell
what color the handkerchief was.

That sounds quite fringe,
but I've done some experiments.

It's a rare ability,
but I did find one person

who was able
to detect the colors

through the fingertips.

I can't explain it,
but she could detect color

with 80% reliability
through her fingertips.

It's been discovered

that the skin has opsins
embedded in them.

And opsins help the body
calibrate

to circadian rhythms,
to 24‐hour rhythms.

So it's not too much of
a stretch to think how opsins

could not just detect light but
they could also detect color.

Many people believe

that there are mysterious ways
of sensing things

that don't involve
the traditional senses.

And I believe that there's a
perfectly reasonable expectation

that that may perhaps be true.

We don't really understand
how the brain works at all.

As incredible as it is

to discover new senses,
it's also a little unsettling.

Because if our brain
is just using our senses

to constantly try
and guess what reality is,

then how are we to know when it
guesses wrong instead of right?

I like to think of perception

as a kind of controlled
hallucination, because

there's no light in the skull,
there's no sound in the skull.

All you've got to go on
as a brain

are these noisy
and ambiguous sensory signals.

Signals don't come with labels‐‐

"I'm from a coffee cup"
or "I'm from a cat."

And this is why, for instance,
if you look up at the sky,

and there's some fluffy clouds,
sometimes you might see faces.

Reality is not quite
as real as people think.

We are often told
that something looks red

because it reflects
more red wavelengths.

But there's no such thing
as red wavelengths.

Color is not a property
of objects.

It's a property of brains.

It's simply the wonder that our
brain is creating all of this

and that we can agree
on so much.

Perception is
about representing the world

and the body and the self

in the way that's most useful
for the organism.

So if you see a color,
that's not right or wrong.

Color is where
the brain meets the universe

in a way that's useful for us.

I think we can all agree
reality exists.

We think,
therefore something exists.

But what it is

and how we will know what it is,
is fun to explore.

Whether it's seeing
the world without eyes,

hearing things
no other humans can,

or unconsciously using senses
we didn't even know we had,

humans possess
incredible sensory abilities

that make us wonder‐‐

what else might be out there
that we have yet to detect?

It's a tantalizing question.

One that will, for now,
remain unexplained.

Subtitles Diego Moraes(oakislandtk)
www.opensubtitles.org