Horizon (1964–…): Season 45, Episode 10 - Why Do We Dream? - full transcript

Tonight nearly all 61 million
people of this country

will fall asleep, and each
and every one of us will dream.

There were two lanes on the
motorway so it was a normal motorway

apart from the fact that
all the cars had no people in them.

I'm holding a big glass of milk
and there's a head of lettuce in it.

She was very overweight and
actually was growing a real beard.

It's an extraordinary world
full of pleasure and pain.

I descended from the sky
onto this sort of beautiful...

.. I've been choked and...
stabbed and I've been shot...

But why we dream is
one of science's great mysteries.

I don't know anybody who
isn't fascinated by dreams.



I mean they are...

outrageous events in our lives.

It's only now

that science is beginning to reveal

the bizarre complexities
of this secret world.

Why would Mother Nature

highly activate your brain,
paralyse your body,

sexually activate you

and force you to watch
these things we call dreams, why?

Why would Mother Nature do that?

Much of what we thought we knew
about dreams appears to be wrong.

Without nightmares there is a good
chance that humanity

wouldn't be here at all.

Where do our dreams come from?



If you want to understand

human nature, the human
mind, what makes us tick,

you need to look at dreams.

Do our dreams have meaning?

People intuitively know
that there is something

about their dreams
that is meaningful.

People are endlessly fascinated
by dreams.

Can we use our dreams?

Those people who dream about it
actually end up

performing better the next time.

Throughout human history
there have always been

big ideas
about the origins of dreams.

For decades people thought dreams
were all these so spiritual things

and you know they are.

It's all about hidden sexual desires,
it's all nonsense.

Scientists have long held the
belief that dreams have a purpose.

Dreams have been responsible
for two Nobel prizes,

the invention of a couple of major
drugs, other scientific discoveries.

When you share a dream with
somebody,

you're saying here is some
information about me

that I haven't faked.

and therefore it's reliable,
and therefore it might reveal

something interesting about me.

But it was not until 55 years ago

that neuroscience really
began to study the dreaming brain.

Then American sleep scientist
Nathaniel Kleitman

undertook a series
of remarkable experiments.

He measured the brainwave activity
of his subjects whilst they slept.

Rather than seeing the passive
picture most scientists expected,

Kleitman found quite the opposite.

What they found is that yes,
they seem to fall asleep

and you got these big waves
but then after not a very long time

it became fast and low
amplitude again

as if they were awake
but they weren't.

So it looks like while you're
asleep, the brain can shift

between different states, different
stages of sleep we say now,

some of which
looks very much like wake.

And when Kleitman examined these
active sleep cycles, he noticed

something else - the sleepers'
eyes appeared to be blinking.

Kleitman called it
Rapid Eye Movement, or REM sleep

and it would lead to his greatest
discovery. During REM sleep,

what the researchers invariably found

when they woke up a subject

was the subject would say, "I'm
dreaming. I just had a vivid dream. "

Kleitman had pinpointed
when we dream

but he found while our brain
and eyes were active,

the effect of REM sleep on our
bodies was exactly the opposite.

Another feature of REM sleep
is that your muscle tone

just goes absolutely down to zero.

You become functionally paralysed.

If you're sitting up in a chair
watching TV, and the head nods

and falls and you fall asleep,
that's not REM sleep.

If you fall into REM sleep, you
would literally roll off the chair

onto the floor because your body
becomes absolutely relaxed,

almost paralysed in the sense
that you can't make your muscles

actually work and it becomes
absolutely calm and non-responsive.

Kleitman and his team
had made the first step

in explaining our dream lives

but it would take some far more
audacious experiments

to enter further into the secret
world of dreams.

This cat looks as if it's awake.

In fact, it's fast asleep.

A dog appears to try running.

It too is asleep.

In order for these dreams to be
seen, the animals were subjected

to radical surgery.

Scientists removed the part of the
brain responsible for paralysing

the muscles during REM sleep.

And what we see is that when you
do this, with cats in particular,

is that they, they can walk around
during REM sleep and their behaviour

is not random, it's not chaotic.

They're not just doing
any old crazy thing.

They appear to be doing the kinds
of behaviours that cats like to do

like stalking a prey, you know
play with a mouse or something.

So presumably that's what they dream
about when they go into REM sleep.

So that's what we think is happening.

These experiments gave scientists
an insight into the dream world

of animals.

Repeating such radical surgery
in humans was unthinkable.

Researchers still sought a way
to observe people

living out their dreams.

One rare brain disease
offers a possible answer.

Well, I'm not an aggressive person.

No, not aggressive at all
but he is when he's got...

It's a Jekyll and Hyde thing.

Yeah I'm saying Tommy,
stop it, stop it!

Stop it!

And I said what are you doing and
he said "I'm picking the parrot up. "

And I said, "You what?" And he
said, "I'm picking the parrot up. "

And he don't even know that
he's told me that, do you? No.

Tom and Tina Cursley have been
married for 42 years.

Three years ago Tom retired
from running a garden centre

and that's when he started
to cause a rumpus in the bedroom.

Well, it was me telling him
he's got to go to the doctor's

and sort this out because
I'd have to jump out of bed quick.

I'd think I was running and kicking,
and my arms were going...

I didn't know what he was going
to do cos he was aggressive.

Tom had begun to act out his dreams
and there was one that caused him

to be particularly energetic
at night.

I can picture now being in this
field, a river in the background

and I don't know,
about a dozen cows grazing the grass

and they suddenly started
coming towards me

and there's this high fence
all round it

and I'm backing up to the fence,

getting out of the way
but they keep coming.

And I try and
jump over the fence

but there's no way
I could jump over it.

The cows keep coming and nudging me
and push me out of the way.

As he dreams,
Tom thrashes about the bed.

He's just horrible really.

He's shouting and... raging
about everywhere.

The bedside cabinet went over the
other night and he didn't even know

he'd knocked that over but everything
went flying, didn't it? Yeah.

Everything.

Light, clock, tablets,
and he never even woke up.

It is, it is awful because
I mean, why is he doing it?

Tom is suffering from a rare brain
condition called REM Sleep Disorder.

Dr John Shneerson

is one of Europe's leading experts
on this condition.

It's absolutely classical for
the REM Sleep behaviour disorder.

It starts off with movements
that the partner thinks

is a bit unusual but nothing special,
just kicking and just a bad dream,

but it becomes more frequent,
more intense

and it can be dangerous for the
partner and dangerous for the dreamer

who may dive out of bed and have
quite severe injuries.

A lot of people with this condition
end up with nothing in their bedroom.

They take out all the bedside tables,

all the lamps, all the sharp corners,
which might injure themselves.

They end up almost in a padded cell.

The condition is caused
by a gradual destruction

of a part of the brain stem
called the Pons.

The Pons controls the
muscles in REM sleep

and the disorder is in some cases
a pre-cursor to Parkinson's Disease.

Some sufferers who have a more
severe form of the disease

demonstrate very vivid dreams.

As in this video, a sleeper
puffs on his finger monitor,

dreaming that it's a cigarette.

Here a French veteran dreams
of marching on the parade ground.

Another patient was dreaming that
there were animals coming in the room

and he woke up on the mantelpiece
and found it difficult to get off.

He didn't know how he got up
there. He must have been very agile,

very motivated to get that far.

It's only a tiny part
of the brain

which prevents us
from acting out our dreams.

Part of the activity of REM sleep is
to turn off the connections between

these centres in your brain
and the muscles themselves,

so if you have, you could have all
sorts of thoughts

and activity within the brain,
and nobody could see it from outside.

Whilst for the sufferer REM Sleep
Disorder can be unbearable,

for scientists it fulfils the ambition
of seeing somebody else's dream in action.

After 55 years of delving ever
deeper into the sleeping brain,

the new cutting edge of dream
science is dramatically changing

our understanding of dreams.

Erica Harris is one of the
new breed of dream scientists.

As most other people battle
the rush hour to get home,

she's arriving for work
at Boston University,

a world centre
in this ethereal field.

The experiment tonight

won't probably end till about 6.30
or 7am when we're finally done.

It's very tiring but we enjoy our
work so we're looking forward to it.

Also arriving
is her guinea pig Ross,

a 19-year-old student who has
come here for a bad night's sleep.

Hello! Oh, hello, I'm Ross. Hi, Ross.

The aim of the next eight hours
is to measure the emotional journey

that Ross is going to undertake
as he dreams through the night.

This is to measure any different type
of muscle movement that he might have

at his eyes or at his chin.

We need to measure the brainwaves
because the brainwaves look different

depending on the different type of
sleep that the person goes in.

The researchers will
monitor his every brainwave

and movement throughout the night.

There are 26 different electrodes
that Ross will have on tonight.

We're going to have a pretty good
idea about everything

that is going on
with him while he's sleeping.

Even with all this technology,
there is still only one way

to find out whether Ross
is dreaming. Sweet dreams.

The project leader
is Professor Patrick McNamara.

There is no technology that allows us

to know 100% certainty
that a person is dreaming.

You can see the full panoply of
characteristics that occur

during REM sleep - the paralysis,
the eyes darting back and forth.

You can put him under a neuro-imaging
scanner. You can see the areas

of the brain that light up
during REM sleep light up

and you can expect them to report
a dream when you wake them up

but they may not.

Unfortunately the best way to find
out if a person is dreaming

is to wake them up and ask them.

Despite this limitation,
the experiment will examine

how our dreams play a central
role in our mental well-being.

So this should tell us something
crucial about the nature of the mind

because if you want to understand
human nature, the human mind,

what makes us tick,

you need to look at dreams.

It's now eleven o'clock
in the dream labs in Boston,

and Ross has gone to sleep.

But it's going to
be a long hard night.

Our sleep is divided
into 90-minute cycles.

The first two are
dominated by deep sleep

when our brain is mainly passive.

After that we alternate between REM
and non-REM sleep.

On this monitor we are looking for

him to descend into the various
stages of sleep so we want him

to make his complete sleep cycle
prior to us awakening him.

Ross has entered the first cycle
of REM sleep

where we know dreaming takes place.

But thirty minutes later
he starts another stage of sleep,

called non-REM sleep.

Right now what we can see is that
he's in non-REM sleep,

because the shape of the brainwaves
are very close together like this,

and then we see some
that are very spiky.

This is the beginning of the
transition to the stage in which

we want to wake Ross up.

Dream scientists used to think
that this was just an insignificant

stage of sleep and that we
only dreamt in REM sleep.

But the great surprise of the past
few years is the discovery

that we dream in non-REM sleep as
well, as the experiment confirms.

It's four o'clock in the morning.

Ross, wake up,
it's time to do your packet.

Ross is woken from non-REM sleep and
does indeed report having a dream.

I was with people I knew,

no real friends as specific
but I was with people I knew

and we were

trying to find somewhere.

It is not just that we
dream in non-REM sleep.

This groundbreaking experiment
is starting to find

that these two dream worlds
are fundamentally different.

So the first thing that he's working
on right now is a mood questionnaire

and basically he might
see three letters like O P T

and he's supposed to
complete some kind of word for that.

The words Ross chooses will indicate

how positive he's feeling
about himself in non-REM sleep.

He appears to be feeling
very good about himself.

We found in our experiment there
was a very reliable difference

in self-concept, self-regard
and there was an increase

in positive regard of the self
after awakenings from non-REM.

Ross goes back to sleep.

The next time he's woken
he will be well into REM sleep.

5 am.

Ross, time to wake up.

This time Ross reports a
number of negative words.

McNamara speculates
that the difference in the nature

of these dreams can be traced back
to an ancient structure of the brain

called the amygdala
that is linked to our emotions.

I think that we have more negative
emotions during REM-related dreams

because during REM sleep,
the amygdala is very highly activated

and the amygdala specialises
in handling unpleasant emotions

like intense fear
or intense anger or aggression.

Finally the long night is over
and Erica goes home,

but the experiment
has more to reveal.

McNamara is beginning to connect the
balance of REM and non-REM dreams

with the mental
well-being of us all.

It could be a factor in depression.

Normally we fall asleep through
non-REM sleep but depressives,

people with endogenous depression
or severe depression,

they go right to REM
and then they stay in REM

and they spend too much time in REM.

So if REM sleep is associated with
all this unpleasant emotion

and you get too much REM,
then you are going to have

a lot of unpleasant emotion.
We call that depression.

So decades after the discovery of
REM sleep, scientists are beginning

to understand the extent to which
dreams shape our waking lives.

I descended from the sky onto this
kind of beautiful fairytale planet.

I had a flat cardboard box,

you know those ones
that you assemble together,

and I took it up to this pyramid
and it had a severe drop at one end

and I put it together.

And then I jumped down
off the pyramid in the box

and hit the pavement but the strange
thing was it didn't actually hurt.

There's like this kind of spaceship
in the sky, very scary and all the

water puddles if you touched
them you had, you catch on fire.

To find out why dreams are
so central to our lives,

one man has studied
those who don't dream.

I frequently found
when I ask patients

after they have sustained strokes
whether they are dreaming or not,

initially they're not entirely sure
and then it's in the following days

because they are now paying attention
to their dreams

that they report to me
that they are no longer dreaming.

Many of us believe we don't dream.

In fact most of us do,
it's just we can't remember them.

But Professor Mark Solms
has spent much of his career

waking the rare individuals
who really do not report dreams.

Following a stroke three years ago

Heather Jones had just
such an experience.

Before my stroke I definitely was
someone that had lots of dreams.

After my stroke it was just,

literally going to sleep
was like going into a blankness.

It's almost as if you're
just absent for a while.

There was just not that same sense
in the sleep or when I was waking up

that I'd been dreaming.

There was no memory of dreams and
no sense of having been dreaming.

Heather's stroke affected a part of
the brain called the parietal lobe.

Solms believes
this is where dreams are made.

People with parietal damage, like
Heather sustained, frequently stop

dreaming completely in the early
stages after the onset of the damage.

That's because the parietal lobe

serves the purpose of combining our different
senses, hearing and vision and touch.

All come together there
and the imaginary space

that we are living in during our dreams
is generated in that part of the brain,

so if it's damaged you can't dream.

This loss of dreaming
has debilitating consequences

as Heather knows only too well.

Although I could go to sleep very
easily, I wasn't having

what I would call
good quality sleep.

At night probably waking
several times through the night

so I wasn't getting a continued
sort of period of sleep.

When I woke up,
I just felt tired still.

The relationship
between sleep and loss of dreaming

is in fact something that
I'm busy researching at the moment.

Our preliminary findings suggest
that at least non-dreaming patients

fall asleep perfectly easily but then
they keep on waking up throughout the

night, in fact particularly during
REM sleep. It's almost as if

when you might have expected that
they would be dreaming, they wake up.

As bizarre as it may seem,

Solms suggests dreams
could be a way of keeping us asleep.

Solms has found that another part
of the brain, the motivation system,

is also active during dreaming.

And this has given him a further
idea about the reason why we dream.

The fact that this part of the brain,

the seeking system, is so active in
dreams, suggests that dreams,

at minimum we have to say

that dreams have some
kind of motivated search in them.

We're seeking something
in our dreams.

It may be the actual storyline of
the dream when we find ourselves

wandering about some strange
landscape looking for something.

Maybe that's
how this expresses itself.

Solms believes
that this seeking activity

symbolises the search for answers.

More likely, cos it's a more general
an explanation,

is that we are grappling with some
sort of problem in our dreams

and trying to find a solution
to some matter of current concern.

There's a kind of a searching
involved in that.

In time, Heather made a recovery

and once more she was able
to benefit from dreaming.

It was an excitement really
when I began to dream again.

I did tell people about it.
I told my partner, I told my physio

cos it was something that I
hadn't thought would return.

If you're aware of having dreamt,

that contributes to a feeling
you've had a good night's sleep.

And that's certainly how I feel.

So science has revealed
that dreams may have many purposes,

a good night's sleep
a way of seeking solutions.

They may even be a way of
maintaining our mental health.

I was playing in my room
with my sister

and then I was about to go outside
and my mum said,

keep your head up
because there is a witch about.

I was in the kitchen. I remember
it had really bright colours

and a lot of sunshine

and I saw a bug on the table and I
heard it say, "hamburger, hamburger. "

I take off and fly and I'm starting
to accelerate faster,

faster, faster and I realise I was
an electron inside an RCA circuit

moving around at the speed of light.

Whilst science has begun to unravel
many of the mysteries of dreams,

there is one question that
has endured more than any other.

Do our dreams mean anything?

My interest in dreaming
as a scientist is boy,

I just want to understand
these things.

It's just so interesting
and so exciting.

What is more interesting
and fascinating

and psychological than dreaming?

People intuitively know that there is
something about their dreams that is meaningful.

People are endlessly fascinated
by dreams.

This belief
that dreams mean something

has been shared across the globe and
remains central to many cultures.

Deep in the forests
of Northern Canada

on the banks of Sesikinikak Lake,
live the Itikemek people.

Interpreting the meaning
of their dreams

is at the very core
of the tribe's belief.

The Itikemek gather for
their morning dream circle

in which they share their dreams,

the elders drawing on their folklore
to tell them what they might mean.

Marianne is the elder and most
versed in understanding dreaming.

In the dream circle Pauline tells
of a second dream about her son

Ivan, a drug addict.

For the Itikemek,

the question of whether dreams have
any significance is beyond doubt.

But is it possible for science to
find out what they might mean?

Throughout the 20th century
many psychologists,

led by Sigmund Freud, thought dreams
were symbols from our unconscious mind

which need to be interpreted.

Now in the Canadian city of Montreal
the power of modern mathematics

is being used to tell us
what dreams mean.

There is convincing evidence
that leads us to believe

that the content of dreams

tell us a lot about how
the brain can process information,

and is important for our
psychological well-being.

Antonio Zadra is a scientist in the
University of Montreal's dream lab.

Here he's collected
thousands of dreams.

Each has been analysed to
see exactly what it's made of.

This rich content
is then turned into numbers.

Well, what we did is we
coded the entire dream series

in terms of various elements.

Who are the characters,
the emotions, the settings?

And then we entered these
quantifications,

these resulting numbers
in our spreadsheet.

The result of this
painstaking process

is a comprehensive database
of our dream lives.

Zadra can tell us how often
we dream about sex,

and whether it involves our partner
or even a celebrity.

He can even tell us
how often we have negative dreams.

But his database
doesn't explain the many.

It is most revealing when telling us
about the dreams of an individual.

We want to see a whole
series of dreams

so that we can then detect patterns
that recur over that entire dream series

and thus get a better idea of what this
person's dream life is generally like.

By comparing these elements against
the norm, Zadra can interpret

what someone's dreams mean.

This is a series of dreams
from a 48-year-old professional man.

He calls his wife B.

B and I are making breakfast.

I was also brewing some coffee but
when I looked over at the coffee

maker it was... overflowing.

There was coffee all over the counter
and coffee just kept pouring out...

B kept on yelling what did
you do, what did you do?

I tried unplugging it...
I removed the glass container

but it wouldn't stop.

His mother arrives, he's
inconsolable and parents too.

But the mother keeps telling people

it's all my fault, it's loud and I
try to defend myself like wake up.

And from this series of dreams

Zadra spots misfortune
as a recurring feature.

When I tried to move the car
the wheels just kept spinning...

B was getting very upset
and was telling me there

was still too much snow. I got out
again and everything seems OK...

I got back in but nothing happened
just more spinning...

In fact 80% of these dreams
contain some sort of misfortune.

Yet on his database, Zadra finds
the average occurrence of misfortune

in the dreams of middle aged men
is just 30%.

The other thing that really stands
out with his dream series

is that almost all of the other
characters in his dreams are women.

There's an, almost an absence of
male figures and the interactions

he has with these women
is almost invariably negative.

Once more the frequency of these
negative dreams about women

is far higher than the norm. If
I were to make an educated guess

about what is going on
in this particular man's life,

is that there seems to be concerns
about relationship issues

and also he is definitely
overwhelmed by factors

which are impacting him negatively

but which he feels
he has no control over.

So it came as no surprise to Zadra

to learn what happened
to this couple.

Five years later they divorced.

Zadra has worked out the norm
for many dream events.

Only a fifth of woman's dreams
about sex involved their partners

but for men it's even less,
just a sixth of the time,

and women should be dreaming
about having sex with celebrities

twice as often as men.

But sadly more than three-quarters
of our dreams are negative.

Most of all,
the database reveals that our dreams

are a much more straightforward
reflection of our waking concerns

than previously thought.

Dreams do not hide their meanings
but are relatively transparent

and I think there is good evidence
to suggest that dreams

tend to reflect people's
emotional concerns

and also things that preoccupy them
in their social lives.

Dreams don't just have meaning.

They have been the source of some
of the great moments of genius

in human history and ultimately
have changed the world.

Dreams have been responsible
for two Nobel prizes,

the invention of a couple
of major drugs,

other scientific discoveries,

several important political events
and innumerable novels,

films and works of visual art,

so they've been very important
in our society.

Professor Deirdre Barrett from
Harvard Medical School has been

studying just how it is that dreams
can help us solve problems

which we cannot crack
in our waking lives.

We can see things much more clearly
when we think about them in dreams

and it also helps us
think outside the box.

Our associations are looser and
more intuitive and less linear.

The classic symbol of science,

the periodic table of the elements,
is said to have come

to the Russian chemist
Dimitri Mendelay during a dream.

In 1844 American inventor
Elias Howe was trying to design

his first sewing machine

but he couldn't work
out how to make it hold the needle.

One night he dreamt of being
attacked by savages with spears.

As he woke up in terror,
the last thing he saw

was that all of their spears had the
hole at the pointed tip of the spear

and he realised that's where you put
the hole in a sewing machine needle.

This extraordinary creativity
can even be found in literature.

The story of Frankenstein
was dreamt up by Mary Shelley.

This ability to harness dreams
and solve problems

is not just the preserve of genius.

It seems that many of us
can also do it.

Just say to oneself,
I want to dream about X tonight

as you're drifting off to sleep
and in my research

I find that about 50% of people
can do that

if they just practice that
for a brief period of time,

and about half will get an
answer that is really gratifying

to whatever the issue is.

But the usefulness of dreams
does not just stop there.

It has recently been discovered
that we can use our dreams

to help us learn in our sleep.

The scientist behind this
latest breakthrough

is Professor Robert Stickgold.

A dream tells us more in some ways
about what's happening in the brain

while we're sleeping

than any other scientific method
we have of investigating it.

Stickgold has devised an
experiment that reveals

just how dreams affect our learning.

just how dreams affect our learning.

So John here is
mostly just having a lot of fun.

He's learning how to play this game,
Alpine Racer II,

which is
a downhill skiing simulator.

He actually controls that character
on the screen by moving his feet

and he's learning a lot about how
to do it, and what we think

is that as the brain goes to sleep,

it's going to come back
to these images.

It's intense. I'm trying to beat
a time and I'm trying to stay

in between these gates and it's
difficult, but it's a lot of fun.

Once John has gone to sleep,
Stickgold wakes him

through the night
to see how his dreams have changed.

Stickgold found that whilst subjects
initially dream about the game,

their later dreams
draw on other memories.

Please report now. I was walking
through... bootprints in the snow.

Some had made bootprints like
copying them,

going into the ones,

stepping into the ones
that were already stepped in,

like following somebody else's steps
along in the snow.

The image that he gets is walking
through snow and stepping into the

steps that he or someone else had
laid down before him, and of course

how much easier it is to walk
through the snow if you go exactly

where you stepped last time.
In these associations,

Stickgold perceives a clear link
between dreams and memory.

I have this image that
what's happening

is the brain is not just paying
attention to the game

but is trying to say, what is that
like, what other memories do I have

that's like that? And he thinks
about moving through snow

and I can just imagine the brain
trying to say,

so when I try to ski
this next time,

shall I try to do it exactly
the way I did it last time?

As John takes to the ski game once
again, his performance has improved.

I was kind of hitting the wall
coming up on this part

but I think I can avoid it...

Yeah. I think that's pretty good.

And it is this improvement

that demonstrates dreams
are central to the way we learn.

They know that they are getting
better when they play again

and in other studies we've evidence
that when they dream about it,

those people who dream about it

actually end up
performing better the next time.

So in dreaming, Stickgold believes
that we are bringing new experience

to bear on old memories,
and this is how we learn.

Maybe the most important thing we
do with memories is not keep them

crystallised the way they happened,

but taking them apart and
figuring out what's important

about what happened to us, and how
that relates to everything else

that's happened in the past,
and figuring out what that means

about our future, about what we are
going to do tomorrow, a month in the

future, a year in the future,
how can I use that information.

In some ways, the most brilliant
thing that the human brain can do

is that kind of extraction
and meaning-making.

As we slumber through the dark hours
of the night, these visions

which haunt our mind are not just
random signals in our brain.

They have a purpose.

Science has shown that there is
an important connection

between our dreams and our memories.

As well as these beneficial traits,

we all know that dreams
have another side.

It's dark outside, kind of raining,

very, very, scary ominous, and it's
like this kind of spaceship...

And an arm with these huge chains

with this big stone tablet all
inscribed with hieroglyphics...

A man comes through the back of
the wall behind the bed and he comes

through the wall like this kind of
thing and then he gets a hold of us

by my feet and he starts pulling
us out of my bed

and then I feel as though I'm trying
to cling on to the bed

and he's saying really horrible
things, really scary things.

There is one man who believes
these terrifying incidents

are good for us, that without them
humanity could not survive.

Antti Revonsuo is a Finnish
scientist who collects nightmares.

He thinks that many of the
bad dreams we have today

are the same as those experienced
by our ancient ancestors.

Oh, it's pretty certain
that our ancestors did dream

because dreaming seems to be
biologically programmed

into our brain, and the brain
that our ancestors had

was pretty much identical
with our brain.

And we know that our ancestors lived

in an environment which was full of
all sorts of fatal dangers.

What has led Revonsuo
to these conclusions

is his study of children's
nightmares.

There was one wolf and he started
chasing me, and I ran and ran

and ran, and afterwards,
he stopped for a minute and barked,

and then another wolf came and
another and another and another

and then in the end there was a whole
pack of wolves with big long teeth

and they were very, very hairy
and big and scary

and they started chasing me.

According to Revonsuo,
we have inherited these dreams

populated by wild animals
and monsters for a reason.

They are rehearsals
for the daily struggle to survive.

The nature of bad dreams
and nightmares

is that they contain
threatening events

and they force us to go through
those simulated threatening events

in order that in the waking world

we encounter similar or different
kinds of threatening events

and then we are more prepared
to survive those

when we have been training for them
in our dreams.

This mechanism for rehearsing
stressful events will stay with us

for all our lives,
but as we grow up,

dreams about wild animals are
replaced by modern horrors.

I was dreaming that I couldn't find
the class

and then my friend had to come to
this class

and I couldn't find her either
and she couldn't find me

and on my way to the class,

the elevator,
you know, I opened the elevator...

the door of the elevator and I
hit a little girl and she died.

Adults have very modern types of
nightmares and bad dreams

like losing your wallet, crashing
you car or something like that

so it seems our brain

is capable of adjusting itself
and including more modern threats.

Although we may dread our
nightmares,

they actually help us deal with
the day ahead, and as a species,

we should be thankful for these
fearsome visions.

Bad dreams and nightmares
are a good thing.

They force us to be prepared for
similar events in the waking world.

Without nightmares and bad dreams

there is a good chance
that humanity wouldn't be here.

But for some,
the reoccurrence of nightmares,

far from helping us to survive in
the waking world,

has exactly the opposite effect.

There are people who suffer
an experience so dreadful

that it reappears in their dreams
again and again.

The one nightmare I had regularly
when I came back from hospital

was I'd be trapped,
like I was in hospital.

I'd feel like my arms would be like
this, my legs would be like that.

I couldn't move, I couldn't move
any thing and I couldn't speak

and he'd always come, be at the side.

Sarah Michael's nightmares were
caused by events in her waking life.

They started after the relationship

with her then-partner
broke down spectacularly.

And I was just sitting there,
and he could be really normal

and then just flip like that

and just suddenly, he just got up and
stood over me and he just went whack!

Right into, right into here and...
and just like,

it's very difficult to remember
the exact way that he did it.

I just remember this great
big looming person over me

and remember the baby was there,
the baby started crying

and then the first impact
I felt something crack,

and I knew immediately something
was wrong but I didn't know what

and I screamed in pain
and fell onto the floor.

The next day she collapsed in agony
and was rushed to hospital.

There, doctors diagnosed broken ribs
and a ruptured spleen.

Her then-partner
came to see her in Intensive Care.

That was really scary as well

because he was trying to make out
that it wasn't as bad as it was,

so he was telling me that he loved me
and he didn't mean it

but then he would swap and change

and say it was my fault because
that's what he did, he confused me.

When we are traumatised by an event,
the memory is stored

in the part of the brain which deals
with raw emotion, the amygdala.

The memory is frozen there
and replayed again and again.

This is what happened to Sarah so
her dreams, rather than processing

and resolving her memories,
only served to reinforce them.

With every nightmare the traumatic
memories became worse and worse

until they reappeared
in her waking life as well.

Driving, I'd look in my rear view
mirror and I'd think he's behind me,

in the car behind me
but I knew it couldn't be him

but my mind was telling me that it
was him, even though I knew

that he couldn't and literally
I had to stop my car

and I'd have to park up
because I couldn't breathe.

I thought if I can't breathe,
I'm going to crash.

Eventually Sarah became
imprisoned by her dreams,

too afraid to leave the house.

I convinced myself that I was mad.

I felt mad. Everything that I took,
cos I wasn't sleeping,

and I went to my doctor
and I said, "I'm mad. "

After three years of terror,
Sarah was finally diagnosed

with Post Traumatic Stress Syndrome.

Following many months
of counselling,

she was released
from her nightmares.

The more I talked about it, the less
power it had to frighten me

so we'd talk about it quite a lot
but it didn't seem so scary.

Once we did all the talking
it wasn't so powerful

and each time if felt safer and safer

like I could tell you now
and only I don't feel upset

and my hands aren't sweaty,
I don't feel traumatised.

It just seems something that happened
and it's not happening any more.

It's been, it's gone, it's finished.

Sarah's story shows
that the power of the mind

can be harnessed to overcome even
the most debilitating of dreams.

It appears that there is a fine line
between dreaming and being awake.

What keeps them apart

is the degree to which the outside
world impinges on our consciousness.

The relationship between
dreams and consciousness

is I think we could actually say that
we are dreaming all of the time.

It's just that during
wakefulness our dreams are shaped

by stimulus information
that's coming through our senses,

whereas during dreaming, the same
consciousness within our brains

is not shaped
by any external information

but it's generated internally.

So I think that life is a dream
which is guided by the senses.

When awake, we appear to have
control over our conscious state

but there are a rare few

who can extend control of their
consciousness into their sleep

and bring the worlds of dreams
and wakefulness together.

These people are
called lucid dreamers.

For one controversial scientist,
an episode of lucid dreaming

was so powerful it changed
the course of his life.

His name is Stephen LaBerge.

I had a couple of lucid dreams
where you know just spontaneously

I had, "ah this is a dream
and this is interesting,

"I want to learn more about it. "

I started reading books about it
and found out

in the late '70s that most experts
in sleep research and dreaming

thought that lucid dreams
were impossible.

LaBerge set about
proving the experts wrong

and devised an ingenious
experiment to do so.

Before his subjects went to sleep,

LaBerge gave them a simple
instruction -

if they became aware of a flashing
light during their dream

they were to move their eyes,
first left and then right.

Then as they dreamt,
LaBerge shone a light in their eyes.

Remarkably the dreamer responded.

A person could simply look to
the left and look to the right,

and left to right, and that would be
a pre-agreed upon signal

and so indeed that turned out
to be possible.

Having demonstrated that lucid
dreaming was possible,

LaBerge left the world
of science behind.

Nowadays on the big island
of Hawaii,

LaBerge gathers groups of people
for lucid dreaming workshops

and he uses a technique which draws
on his early experiments.

The students are given a mask
with a flashing light.

If they can learn to respond
to this whilst asleep,

then they are lucid dreamers.

LaBerge wants his students
to go one step further

by learning how to become
self-aware during their dreams.

So one of the best dream signs

is not even what you are
seeing or feeling

out in the inner dream world.

It's reflecting on your thoughts

of what's going through
my mind right now.

And asking the question
would this happen in real life?

If my count of limbs multiplies,
I know I'm dreaming

cos they don't usually
just reproduce like that OK?

Most people are here to explore
the amazing world of dreams

and for some, LaBerge believes
it has a more serious use.

Facing and overcoming nightmares

is I think one of the most
important applications.

For people with nightmares, it's
learning to understand what they are,

they stop frightening you and it's
a very compelling powerful tool

for personal integration, I believe.

For Justin it's the hope
of overcoming nightmares

that has brought him to the island.

Well, I'm basically hoping to develop
my ability to have lucid dreaming.

I am a recovering alcoholic and I'm
bothered a lot of times by dreams

about drinking and anxiety, and those
are very disturbing kinds of dreams

and I would really like to be
able to gain control over those

and work through it in my sleep
so that when I am awake

I can help myself to reduce
my thoughts about alcohol.

That night Justin, helped by the
flashing lights of the facemask,

goes to bed determined
to take control of his dream.

In the morning,
he reports to the group.

I was having sex

and I saw a flash of light
off to the side

and I saw someone taking photographs.

My first thought was I've got to
get the camera and I chased him.

In this scenario, LaBerge sees
the first signs of lucidity.

The camera represents
the flashing light.

Next time I'm having sex and lights
are flashing I'll just say hey...

does this usually happen?
LAUGHTER

Over the next few nights
Justin hones his skills

until he finally has
his first lucid dream.

It was one of the most
exciting things

that has ever happened to me.

I was asleep and suddenly I realised
I was awake,

and I just had a flood
of excitement and ecstasy

and was aware that I was dreaming

even though I was in the bed and
I was able to do incredible things.

I stretched my arms really far

and I drew a door in the air
with a pencil

and then became so excited,
I woke up.

Taking control of our dream lives
is an ability from which

LaBerge believes we can all benefit.

It seems to me that lucid dreaming
is a skill that ought to be taught

in grammar school where it's just
hey here's something you can do.

It's a place you can
experiment with your life

without worrying about consequences.

So science is finding our dreams
are many things.

A crucial evolutionary device
developed by our minds

to help us consolidate our memories.

A way to solve our problems.

Dreams even help us to survive.

Throughout the long night,

our mind is training us
to face the coming day.

The important thing is just to go
through the training and then we get

all the training benefits,
even if during wakefulness

we have no idea
we've been training all night.

I think that their value lies

in what a different mode
of thought they are.

They're so much more intuitive
and visual a mode of thinking

and in our culture,
we spend so much time

in this very logical
linear mode of thinking

that their main benefit lies

in presenting
such a different point of view

to how we usually approach things.

Our brain is working on figuring
out the importance

and significance of events
from our days,

how they fit together
with old events in our past,

what they mean about likely events
in the future

and if that processing
is functional,

as I believe it must be, then our
dreams are telling us something

about what's important to us and the
meaning of the events in our lives.

So tonight, as you enter the
wonderful world of dreams,

lie back and let your mind take
you on the adventure of a lifetime.