Nova (1974–…): Season 36, Episode 16 - What Are Dreams? - full transcript

To sleep researchers the various aspects of sleep and dreams make no sense unless they have a purpose. What that purpose is is fertile ground for research, speculation and disagreement. This program presents the ideas and research methods of several active sleep researchers.

Are you wondering how healthy the food you are eating is? Check it - foodval.com
---
Each night, as we close our eyes

and slip away
from the waking world,

we may enter
an even richer one...

the elusive realm of dreams.

I was in a kitchen.

I remember it had really bright
colors and a lot of sunshine,

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

"Hamburger, hamburger."

I was riding the subway,

and I noticed that I could
suddenly see into things.

And there was a young woman, and
in her purse she had handcuffs.



There were two lanes,

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.

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

I mean, they are outrageous
events in our lives.

They can be bewildering,
terrifying, inspiring,

but do they mean anything?

Are dreams the nonsensical
byproduct of a sleeping brain

or a window into our unconscious
mind, rich with revelations?

Why would Mother Nature

highly activate your brain,

paralyze your body,
sexually activate you



and force you to watch these
things we call dreams? Why?

Why would Mother Nature do that?

After more than a century
of searching,

scientists may finally be
nearing an answer

by literally watching dreams
unfold

and testing their impact on both
our sleeping and waking lives.

Dreaming is a process,

and not only is it useful,

it might be essential for making
sense of the world.

- Up next on NOVA,
- "What Are Dreams?"

Captioning sponsored
by EXXONMOBIL,

MERRILL LYNCH,

PACIFIC LIFE,

DAVID H. KOCH,

the HOWARD HUGHES
MEDICAL INSTITUTE,

the CORPORATION
FOR PUBLIC BROADCASTING

and VIEWERS LIKE YOU

Major funding for NOVA
is provided by the following:

I've been growing
algae for 35 years.

Most people try
to get rid of algae,

and we're trying to grow it.

The algae are very beautiful.

They come in blue or red,
golden, green.

Algae could be converted
into biofuels

that we could someday
run our cars on.

Using algae to form biofuels,

we're not competing
with the food supply.

And they absorb CO2,

so they help solve the
greenhouse problem as well.

We're making a big commitment
to finding out

just how much algae can help

to meet the fuel demands
of the world.

To pursue the life you want,

sometimes you need
a financial advocate

who knows where you want to go.

A Merrill Lynch
financial advisor,

now with access to the
resources of Bank of America,

can help you diversify,
rebalance, imagine and believe.

And by Pacific Life,
the power to help you succeed.

Offering insurance,
annuities and investments.

And:

And...

And by the Corporation
for Public Broadcasting

and:

I was walking down
this really bizarre hallway,

and every time I would
open a door,

there would just be
this blinding light.

So I take off and fly

and I'm starting to accelerate
faster, faster, faster

and I realize I was an electron
inside an RCA circuit

moving around
at the speed of light.

It's dark outside,
kind of raining,

very, very scary, ominous,

and all the water puddles,
if you touch them,

you catch on fire.

She was very overweight

and actually was growing
a real beard.

They're eerie, impossible
and often just plain weird.

Yet some say
they've changed the world.

Dreams have been responsible
for two Nobel prizes,

the invention of a couple
of major drugs

and innumerable novels, films
and works of visual art.

Usually they fly through
the mind unremembered.

Yet they may be key to
understanding the mind itself.

PATRICK McNAMARA:
If you want to understand

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

you need to look at dreams.

The scientist most associated
with dreams

is still Sigmund Freud,

who saw them as brimming
with symbols, mostly sexual.

Such symbols took form

as the sleeping brain tried
to disguise forbidden urges

welling up from its unconscious.

Though even Freud cautioned
that this kind of thinking

could be taken too far.

At some point, he said,
"You can be too literal.

You can say every single thing

is standing
for something sexual.

And, you know, sometimes
a cigar is just a cigar.

Today, advances in brain science
have inspired

new theories about dreams,

building on a discovery made
years after Freud's death,

when science finally got a look
at the sleeping brain.

The breakthrough came in 1953

when Nathaniel Kleitman
and Eugene Azerinsky

began recording
people's brain waves

as they slept through the night.

They put electrodes
onto the head

that could pick up
the electrical activity

of the brain underneath.

And they had known
when people are awake,

that signal looks very fast
and not too interesting...

It looks almost like noise...

But that when people
fall asleep,

that you would sometimes
have the brain activity

start to go up and down
in a slow pattern

and you could then tell whether
someone was awake or asleep,

or so they thought.

The researchers had assumed

sleeping brains
were resting brains.

But every 90 minutes or so,
as their subjects slumbered,

something odd happened.

Their eyes were closed,
their head had drooped;

they didn't answer
when you called them by name.

They were clearly asleep,

but the electrical activity of
the brain said they were awake.

And it wasn't just their brain
waves that seemed strange.

They were sexually aroused.

Their heart rates and breathing
had become irregular.

Their eyes darted about
beneath shut lids.

It was these eye movements
that gave the state its name:

rapid eye movement,
or REM, sleep.

But what was REM sleep for?

The answer seemed to come
from the sleepers themselves.

McNAMARA:
During REM sleep,

what the researchers
invariably found

when they woke up a subject was

the subject would report,
"Hey, I'm dreaming,

and I just had a vivid dream."

So was REM sleep dream sleep?

The idea seemed more than
plausible when you considered

REM's most dramatic
characteristic.

Another feature of REM sleep is

that your muscle tone just goes
absolutely down to zero.

You become functionally
paralyzed.

If you're sitting up in a chair
watching TV, you know,

and the head nods and falls
and you fall asleep,

that's not REM sleep.

If you fell into REM sleep,

you would literally roll off
the chair onto the floor

because your body becomes
absolutely relaxed,

almost paralyzed, in the sense

that you can't make your
muscles actually work

and it becomes absolutely calm
and nonresponsive.

Nature, it appeared, had devised
a special state of paralysis

to house our dreams...

One in which they remained
internal experiences.

It was a conclusion that seemed
impossible to deny

when researchers learned
to switch the paralysis off.

This cat looks as if it's awake.

In fact, it's deep in REM sleep.

This dog appears to be running.

It too is in REM sleep

and, like the cat, dreaming.

To see these dreams played out,

scientists disabled
the part of the brain

that paralyzes muscles
during REM sleep.

McNAMARA:
And what we see

when you do this
with cats, in particular,

is that they can walk around
during REM sleep

and their behavior is not
random, it's not chaotic.

They're not just doing
any old crazy thing.

They appear to be doing
the kinds of behaviors

that cats like to do,

like stalk 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.

But what about people?

Could human dreams
be watched as well?

Performing surgical experiments
on human subjects

was, of course, unthinkable.

But the discovery
of a new brain disease

also made it unnecessary.

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.

Tom Cursley has a condition
known as REM sleep disorder.

It prevents the paralysis
of REM sleep,

so he acts out his dreams.

I can picture now

being in this field,
a river in the background,

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

and they slowly start coming
towards me and nudging me

and push me out of the way.

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.

Dr. John Shneerson is
an expert on this condition.

It's absolutely classical

for the REM sleep
behavior disorder.

It's just what happens.

It often starts off
with movements

which 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 so it can be dangerous
for the partner

and dangerous for the dreamer.

In fact, a lot of people
with this condition end up

with nothing in the bedroom
at all.

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.

Not all sufferers
have nightmares.

Here, a sleeper puffs
on his finger monitor,

dreaming it's a cigarette.

Another patient was dreaming
that there were animals

coming in the room,

and when he woke up he was
on the mantelpiece

and found it difficult
to get off there.

In fact, he didn't know
how he got up there.

He must have been very agile
to get up there,

and very motivated
to get that far.

REM sleep disorder seemed
to suggest

that dreams were important.

Why else would nature go
to such lengths

to let most of us dream safely?

Such a conclusion might have
seemed obvious,

but by the late '70s, a new
theory was roiling psychology.

It came from Harvard researchers
Alan Hobson and Robert McCarley.

And it stressed the fact

that there's a particular part
of our brain stem

that triggers REM sleep,

sending up signals to the
higher parts of the brain

that were kind of random
and chaotic.

Dreams, the researchers argued,

were more physiological
than psychological,

the result of our higher brain
doing the best it could

to make sense of meaningless
neural impulses.

Now, that led them to say

that dreams have some
psychological coherence,

some pattern,
but they have no purpose,

and certainly not
the psychological purpose

that Freud claimed for them.

So are dreams
basically gibberish

or, as Freud maintained,
a doorway to the unconscious?

Or something else entirely?

For the debate to move forward,
scientists would have to make

yet another key discovery.

As most other people
are heading home,

Erica Harris is arriving
for work at Boston University.

This is when dream researchers
frequently start their day.

The experiment tonight
probably won't end

till about 6:30 or 7:00
in the morning,

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.

Hi.
Hello.

Hi, I'm Ross.

Over the next eight hours,

they will focus
on an aspect of dreams

only recently discovered.

We're so glad
you could make it tonight.

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 brain waves

because the brain waves show us
a different picture.

They look different, depending
on the different type of sleep

that the person goes in.

With this much wiring,

it's unlikely a brain wave
will go unnoticed.

There are 26
different electrodes

that Ross will have on tonight.

We're going to have
a pretty good idea

about everything that's going on
with him while he's sleeping.

But even with all
this technology,

there's still only one way to
find out if Ross is dreaming.

Sweet dreams.

Project leader Patrick McNamara
explains the challenge.

There is no technology
that allows us to know,

hundred percent certainty,
that a person is dreaming.

You can see the full panoply
of characteristics

that occur during REM sleep...

You know, the paralysis, the
eyes darting back and forth.

You can put them 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 probe

a surprise discovery
of the recent past.

Sleep studies have revealed

that not only do we dream
in REM sleep

but during non-REM sleep
as well.

And these two dream states may
be fundamentally different,

affecting us in different ways.

So this should tell us
something crucial

about the nature of the mind,

because if you want to
understand what makes us tick,

you need to look at dreams.

It's now 11:00,
and Ross has nodded off,

which means his brain
has begun to cycle

through the five stages
of sleep.

We start out with non-REM sleep,

beginning with stage one:
light sleep.

As we pass into deep sleep...
Stages three and four...

Our brain waves grow
increasingly long and slow.

Then we begin a return journey,
but don't quite make it.

Just short of waking
comes REM sleep,

after which we repeat the cycle,
four or five times in a night.

On this monitor we're looking
for him to descend

into the various stages
of sleep,

so we want him to make
his complete sleep cycles

prior to us awakening him.

Ross has completed
one sleep cycle,

which lasts about 90 minutes.

Soon he is entering again
into non-REM sleep.

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

and we know that because we see
the shape of the brain waves

where they're 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.

Ross, wake up.

Time to do your packet.

After awakening
from non-REM sleep,

Ross does indeed report
having a dream.

I was with people I knew,

no real friends in specific,
but I was with people I knew

and, uh, we were trying
to find somewhere.

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

As the experiment will reveal,

these dreams are different
from REM dreams.

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 reveal

how he's feeling about himself
after non-REM dreaming.

His answers reflect
positive emotions.

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 awakened,
he will be well into REM sleep.

5:00 a.m.

Ross, time to wake up.

This time Ross comes up with one
negative word after another.

McNamara speculates
that this shift in mood,

detected after Ross's REM dream,

can be traced to an ancient
structure, the amygdala,

found in each hemisphere
of our brain.

McNAMARA:
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 specializes
in handling unpleasant emotions

like intense fear or intense
anger or aggression.

Finally the night is over,

but the experiment
has more to reveal.

McNamara is beginning to connect

the proportion of REM
and non-REM dreams

with our mental well-being.

It could be a factor
in depression.

McNAMARA:
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're going to have
a lot of unpleasant emotion.

We call that depression.

At Harvard, meanwhile,
Robert Stickgold is focusing

on the dreams of non-REM sleep.

He too recruits human subjects
to sleep over in his lab.

But first they get
an assignment.

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.

That night, John is awakened
repeatedly during non-REM sleep

and asked about his dreams.

Early on, they're simple
reenactments of the ski game.

But as the night passes,

they begin to incorporate
other memories.

Please report now.

I was walking through, um,
boot prints in the snow...

Already made boot prints,
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.

What he's dreaming about

is how much easier it is
to walk through the snow

if you go exactly where
you stepped last time.

I can just imagine the brain
trying to say,

"Does what I know
about walking in snow

help me think
about skiing on snow?"

Such a dream, Stickgold
believes, does far more

than while away the night.

And I think this is all about
the function of sleep

and the role of dreaming
in processing memories,

that it refines the memory,
it improves the memory,

it makes the memory more useful
for the future,

and so when they come back,
they're going to be better.

And John is better.

The next day
on the virtual slopes,

his performance has
clearly improved.

Always end up hitting the wall
coming up on this part,

but we'll see if I can avoid it.

Yeah.

That's pretty good.

We know that they're getting
better when they play again,

and in other studies
we have evidence

that when they dream about it,
those people who dream about it

actually end up performing
better the next time.

If non-REM dreams help us learn,

then what about the dreams
of REM sleep?

What do they accomplish?

And how might the two kinds
of dreaming work together?

At MIT, a scientist who
eavesdrops on the dreams of rats

may be nearing an answer.

By placing electrodes
in a rat's brain,

Matt Wilson can read its mind,

seeing exactly how its brain
cells or neurons fire

as it experiences its world...
in this case, a maze.

Individual neurons will respond

based upon what the animal is
doing, where it is in the maze.

So wherever the animal is,

we see unique patterns
of brain activity.

Each of these patterns
corresponds to a specific place

in the maze explored by the rat.

But remarkable as it is to look
in on a rodent's inner life,

the big payoff comes later.

As the rat sleeps,
the patterns recur,

seen here as flashes of color
superimposed on the maze.

So the animal is asleep.

It's not moving.

It's not interacting
with the world.

And yet we see a lot
of structured activity

going on in the brain.

And when we look in detail
at that activity,

we see that these patterns are

direct reflections of patterns
that we had seen

when the animal was awake.

Wilson is convinced he has found
a way to watch a rat dream

and know what
it's dreaming about...

In this instance,
running a maze.

And I think that was really

the moment of great insight...

Not simply that there was
dreaming going on,

but that we had access to this.

Like humans, rats have
two distinct dream types,

and Wilson is homing in
on their differences.

During non-REM sleep, their
dreams play out as brief bursts

of neural activity,
which mirrors past experience

compressed into seconds.

Now, when we get to REM sleep,
now things change dramatically.

Memories are replayed,

but they're not compressed,
they're not accelerated.

They don't occur
in these small fragments.

They are played out

as though the animal were
actually experiencing

moving through a world,

but that world is being
generated from the inside.

In fact, REM dreams
can be five times longer

than non-REM dreams.

And in human beings, at least,
they are anything

but a simple replay of the past.

So the speculation is that
during non-REM sleep,

the brain is taking the past
and trying to figure out

how that might relate
to the future,

and in REM, actually trying
to experience the future,

move into the future.

The dreams of REM,
in other words,

may be simulations which allow
us to face challenges

and test possibilities.

My sense is that when we're
asleep and when we're dreaming,

we are actually conscious
and figuring out

what's important
about what happened to us

and how that relates

to everything else that's
happened to us in the past

and figuring out what that
means about our future.

And when you think
about the challenge

that animals, that we as humans
and the brain in general faces,

it is the unknown of the future.

And in REM, we may have
the opportunity

to step into that future world
with no risk,

because the consequences
are simply

things don't work out as you
might have expected,

and then you wake up.

So these states may be
what are essential

for allowing us, as individuals,

to reach our maximal level
of potential.

When dreams begin testing
scenarios,

the results often
seem ludicrous.

I was in a kitchen.

I remember it had really bright
colors and a lot of sunshine,

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

"Hamburger, hamburger."

I was in a field and I could see
what looked like hundreds

of silver and purple flowers

and as I approached, I realized
that they were actually parasols

and then they would make a sound
like a gong.

But as preposterous
as some dreams seem,

a few may 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.

Deirdre Barrett of Harvard
explores the power of dreams

to give us insights we might
never otherwise have.

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 Dmitri Mendeleev

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 dreamed

of being attacked
by cannibals with spears.

And 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 realized that's
where you put the hole

in a sewing machine needle.

And the story goes that
Dr. Frankenstein and his monster

were dreamed up by Mary Shelley.

Or were they?

Not everyone agrees.

Many of the claims about great
discoveries during dreams

are very hard to document.

But what we always have
to remember is these people

were intensely thinking
about these issues.

So there may have been
some discoveries

based on reflecting on dreams.

But that is waking consciousness
reflecting on the dream.

But even if famous creators
achieved their breakthroughs

after waking, dreams can still
claim some of the credit,

according to sleep researcher
Sara Mednick.

What stage do you think this is?

Looks like stage two.

Mm-hmm, right, because
we have sleep spindles...

In a recent experiment,
she recruited volunteers

to play a series of word games
that demand creative leaps.

We define creativity

as putting together
disparate ideas

in new and useful combinations.

So what we have
is three different words.

And we have people trying
to find a fourth word

that goes with those words.

And so what they have to do
is find a new connection

that's not
their direct associate,

but a more remote associate.

Before playing, volunteers like
Tristan are shown examples.

Try these next two:
surprise, line, birthday.

Uh... present?

No... very close.
The answer is "party."

So surprise party,
party line, birthday party.

After the game, Tristan's
next assignment is to nap.

Mednick monitors his sleep
cycles and eye movements.

60 minutes later, he appears
to be entering REM sleep.

So here we have a lot of rapid
eye movements.

You can see this is indicating

he's probably having
a dream right now.

Only a third of the volunteers
take naps like these.

The others either rest quietly

or are awakened
before entering REM sleep.

Then everyone plays
a new word game.

I was looking

for a REM result for creativity.

I definitely thought we'd
be able to find it.

I was surprised
by the magnitude.

Those who had REM sleep
scored 40% higher.

But quiet rest or non-REM sleep
produced no benefit whatsoever.

The reason why we think

that REM sleep helps you
with creativity

is because REM sleep is a very
active time in your brain.

Sometimes your brain can even be
more active than during waking.

And you actually have these
different areas of the brain

that are speaking to each other.

So it's actually able
to start to free-associate

amongst its own ideas
and memories.

Clearly, REM sleep
can boost creativity,

but do REM dreams have
anything to do with it?

The dreams that we have
during REM sleep,

they're very wild,
they're very fanciful.

They're clearly the brain having
a period of loose associations,

where you're able
to put connections together

between new and old ideas,

finding new solutions
to new problems.

This ability to harness
the creative power of dreams

is not just the preserve
of genius.

It seems that
with a little REM sleep,

many of us can also do it.

Just say to oneself,

you know, "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.

Of course, sometimes we get
the dreams we least hope for.

But these may be the most
valuable ones of all.

It's dark outside,
kind of raining,

very, very scary, ominous.

Um, there's, like,
this kind of spaceship...

arm with these huge chains

was this big stone tablet all
inscribed with hieroglyphics.

Suddenly I jump off the bed;

I want to run into
my parents' bedroom.

There's a long hallway I have
to go through to get there.

And then just at that moment,
this hand and arm and body

reaches for me.

This is the giant
made of shadows.

No doubt, such episodes
are terrifying.

But could it be we need them?

Antii Revonsuo
is convinced of it.

He's a Finnish scientist
who collects nightmares.

He has concluded 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.

The same dangers, Revonsuo says,
often show up

in nightmares today,

particularly
in those of children.

There was one wolf
and he started chasing me,

and I ran and ran and ran,

and afterwards he, 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,
our ancestors had such dreams

and bequeathed them to us,

because they were
indispensable rehearsals

in the 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.

Revonsuo believes

this mechanism
for rehearsing stressful events

stays 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,

I opened 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 your car

or something like that, so it
seems our brain is capable

of adjusting itself and
including more modern threats.

According to Revonsuo,
we should be thankful

for these fearsome visions,

which may exist
to help us survive.

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 if dreams are so important
to our waking lives,

what if one day
they just stopped?

Would we lose our capacity
to learn, prepare, anticipate?

Could such a thing happen?

According to this man, it does.

I frequently found
when I ask patients

after they'd sustained strokes,
for example,

whether they're dreaming or not,

initially they're not
entirely sure,

and then it's
in the following days...

Because they're now paying
attention to their dreams...

That they report to me
with increasing confidence

that they're no longer dreaming.

True, many of us say
we don't dream,

when in fact we just can't
remember doing it.

But Mark Solms is convinced that
the rare individuals he studies

really have nothing to remember.

One of these is Heather Jones,

who lost her dreams three years
ago, after a stroke.

Before my stroke,

I definitely was somebody
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.

But it was damage

to a part of Heather's brain...
The parietal lobe...

Which convinced Solms
she really wasn't dreaming.

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
served 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.

So does going dreamless
have consequences?

Apparently, though they don't
seem particularly dire.

I could go to sleep very easily.

Um, 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 I'm busy
researching at the moment.

Our preliminary findings suggest

that at least nondreaming
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.

Decades after the discovery
of REM sleep,

scientists are beginning
to understand

how dreams affect our lives.

But they are also grappling with
another intriguing question.

Do dreams mean anything?

I descended from the sky

onto this sort of beautiful
fairy tale 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.

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's a witch about."

My interest in dreaming,
as a scientist, is

boy, I just want
to understand these things.

It's just so interesting
and so exciting.

People intuitively know

that there's something about
their dreams that is meaningful.

People are endlessly
fascinated by dreams.

The belief that dreams
mean something

remains central
to many cultures.

Deep in the forests
of Northern Canada

live the Attikamek people.

Interpreting their dreams is
part of the tribe's daily life.

Each morning,

members of the community gather
in dream circles like this one.

The dreamers speak;

the elders draw on folklore
to interpret what they hear.

One elder who practices dream
interpretation is Marianne.

Pauline acknowledges
her son's drug addiction

and then describes
a second dream.

For cultures like the Attikamek,
it is beyond question

that dreams have significance.

But do they?

Can science find meaning
in dreams?

In Montreal, one psychologist is
using statistics, not folklore,

to tell us what dreams mean.

There is convincing evidence
that leads us to believe

that the content of dreams
tells us a lot

about how the brain can process
information

and is important for our
psychological well-being.

Antonio Zadra is a scientist

at the University
of Montreal's dream lab.

Here he has collected over 6,000
REM and non-REM dreams,

breaking down each one
into its basic elements

and turning each element
into a number.

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

in terms of various elements.

Who are the characters,
the emotions, the settings,

things of that nature?

And then we entered
these quantifications,

these resulting numbers
in our spreadsheet.

The result of this painstaking
work is a comprehensive database

of our dream lives.

Zadra can tell us
how often we dream about sex

and whether this involves
our partner or a celebrity.

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

But his database is most
revealing when telling us

about the dreams
of an individual.

What we want to see is 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.

Comparing someone's dream
elements with the norm

tells Zadra what they may 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 was 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
unconsolable, and parents too."

But my mother keeps telling
people it's all my fault.

It's loud and I try
to defend myself.

I wake up.

From this series of dreams,

Zadra spots unhappiness
as a recurring theme.

"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
seemed okay.

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

In fact, 80% of this man's
dreams include unhappy events.

Yet Zadra's research reveals

that the average occurrence
of misfortune

in the dreams of middle-aged men
is only 34%.

The other thing that really
stands out

with his dream series is

that almost all of the other
dream 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.

Again, the frequency of these
negative dreams

is abnormally high.

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

that five years later,
the man divorced.

Zadra has worked out the norm
for many dream events.

Only 20% of women's dreams
about sex, for example,

involve their partners,

but dreaming men are worse,

coupling faithfully just
one out of seven times.

33% of our dreams involve
unhappy events.

And while some dreams
are outlandish,

most are more a reflection
of our waking concerns.

Dreams 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.

Preoccupations that we seem
to be trying to work out

as we sleep.

What's amazing is it looks
like those processes

of extracting what's important,

integrating it
with our other memories

and projecting it
into our future...

Those critical, brilliant
functions of the human mind

and the human brain...
Might actually occur

not while we're awake,
not while we're trying

to figure it out consciously
and intentionally,

but instead while we're asleep
and while we're dreaming.

So what is science telling us
about our dreams?

That they're a crucial tool
which helps us learn...

a key to creativity,
even survival...

a window onto our secret selves.

Throughout the long night, our
mind seems to be preparing 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.

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 we don't know whether
it's going to be fun,

whether it's going to be scary,

whether it's going
to be poignant.

It's a whole new adventure
every time.

So the next time you enter
the elusive world of dreams,

know that your brain
may have good reason

to send you on these adventures
of the night.

On NOVA's "What Are Dreams?"
Web site,

explore the various stages
of sleep

and ask an expert your
questions about dreaming.

Major funding for NOVA
is provided by the following:

Natural gas
is a cleaner-burning fuel,

yet a lot of natural gas has
impurities like CO2 in it.

Controlled Freeze Zone
is a new technology

being developed by ExxonMobil

to remove the CO2
from the natural gas

so we can safely store it

where it won't get
into the atmosphere.

ExxonMobil is spending
more than $100 million

to build a plant that
will demonstrate this process.

I'm very optimistic about it,

because this technology
could be used

to reduce greenhouse gas
emissions significantly.

And Merrill Lynch
wealth management.

And:

And...

And by the Corporation
for Public Broadcasting

and: