ALAN ALDA (Narration) But now watch what happens. Researcher
... to draw that with your left hand.
Joe You got me lost.
RESEARCHER Why don't you try drawing another picture right
over here? That'll help you.
JOE Oh, phone.
ALAN ALDA It's almost as though somebody has given him a
GAZZANIGA That's right.
ALAN ALDA ... and now he knows that it's a telephone... up
until then he was blind to it.
ALAN ALDA (Narration) When Gazzaniga first did this experiment
it instantly proved that the ability to speak resides almost
exclusively in the left hemisphere. Not until he sees what
his right brain is drawing is Joe able to name it.
ALAN ALDA He said church, didn't he?
GAZZANIGA After looking at the picture.
ALAN ALDA But he had to figure it out about as long as we
did. That's really interesting. It's... ah....it's a... picture
here of somebody communicating almost with another person.
GAZZANIGA And the communication is not occurring inside the
head, it's occurring out on the piece of paper.
ALAN ALDA Yeah. Joe Blob. I don't know.
RESEARCHER You want to draw a little bit more?
ALAN ALDA (Narration) So far, Joe has been seeing only one
word. Things get even stranger when he flashed two words,
each to only one half of his brain.
GAZZANIGA The right hemisphere just saw toad.
ALAN ALDA Yeah.
ALAN ALDA (Narration) And so his left hand draws a toad.
GAZZANIGA So there's the toad.
ALAN ALDA Oh, it's a toad.
ALAN ALDA (Narration) And this time I was able to guess what
ALAN ALDA Will he now put a little three-legged stool in
there later, or what...
ALAN ALDA (Narration) Joe's speaking left brain saw "stool".
Saying the word lets his right-brain-controlled hand in on
ALAN ALDA That's great. That's really interesting. And if
he had seen that with the cocus collosum intact, he would've
drawn a toadstool, not the toad and the stool.
GAZZANIGA Right, exactly the point. I've been doing this
for thirty-five years, and it gets me every time.
ALAN ALDA It must, it must.
RESEARCHER This time instead of naming the word I want you
to point to the word.
ALAN ALDA (Narration) Again, Joe sees two words simultaneously.
Bell goes to his non-speaking right brain, music to his speaking
left brain. When asked to point to a picture of what he saw,
he chooses bell. But when asked why...
RESEARCHER Why'd you pick that one?
ALAN ALDA (Narration) And when asked to explain... Joe It
was music and bell and those few minutes... the last time
I heard any music it was coming from the bell out here...
RESEARCHER Uh huh...
JOE ... banging away.
RESEARCHER The bells outside here?
ALAN ALDA (Narration) What's extraordinary is that Joe's
speaking left brain concocts a plausible story of why he pointed
to bell - even when some of the other pictures more obviously
represent music. Gazzaniga believes this determination to
find cause and effect, this desire to explain, to be the left
hemisphere's most marvelous property.
GAZZANIGA One of the unique things of the human brain is
this need to interpret why two events occur. What was the
antecedent of this, what caused this and if you can imagine
that a species like us, that has this little chip in its brain
that asks those questions is going to survive rather well
because it is going figure out more about the nature of the
world than a species that doesn't have it.
ALAN ALDA (Narration) But as I was about to discover, the
right brain has a very useful survival skill all its own.
ALAN ALDA What do you think will happen here?
Researcher For you we're doing a live experiment - never
done it before.
ALAN ALDA (Narration) The experiment involves the 16th century
Italian painter Arcimboldo, who made faces out of fruit, flowers,
meat, even books. Now, from other research there's reason
to believe that the ability to recognize faces is located
exclusively in the right hemisphere. So Mike wondered if Arcimboldo's
paintings would look different to each of Joe's two brains.
GAZZANIGA So while will his left hemisphere say 'I saw a
potato, I didn't see a face'. And will his right hemisphere
say 'I saw a face' and not comment on the fact that it was
made out of the potato.
RESEARCHER You're gonna see a figure followed by a choice
of two words.
GAZZANIGA If this works it will be terrific, but we'll see...
so, here it is, live.
ALAN ALDA (Narration) The first painting goes to the right
hemisphere - and Joe points to "face". The next painting goes
to his left brain - and this time he points to "fruits". Mike
ALAN ALDA Are you having a moment?
GAZZANIGA This is too good.
ALAN ALDA (Narration) Again to the right brain - and Joe
sees it as a face. But to the left brain...
GAZZANIGA ... a face made out of books... he pointed to books.
ALAN ALDA Are you happy with what he's doing?
GAZZANIGA It's unbelievable! He's doing it! Do you see that?
ALAN ALDA It's... he's shifting so fast, he's going from
left to right so fast, I can't keep up with you - you're used
to looking at this.
GAZZANIGA When you show him a face in the right side - the
left hemisphere - he's focusing in on the elements that made
up the face. When you show him the exact same picture in the
left field going to the right hemisphere he focuses on the
face and not on the elements.
ALAN ALDA And not the elements. If you came down from another
planet and you saw faces and vegetables, you might not think
there was much of a difference among them, but the brain seems
to be made up in certain way to say 'faces are very different
from other objects'...
GAZZANIGA That's right...
ALAN ALDA ... and one side of the brain specializes in faces...
GAZZANIGA ... exactly right, exactly right. It is an adaptation
that we have to detect upright faces. It's a very important...
you can imagine in an evolutionary time that all of a sudden
you have the ability to detect quickly an upright face, you
want to read the expression on that face, you want to know
if it's friend or foe, you wanna have a set of questions about
ALAN ALDA (Narration) The right brain might be skilled at
recognizing faces. But when it comes to what gives the human
mind its power - the ability to reason, to invent, to interpret
the world around it - Mike Gazzaniga's thirty years of research
has taught him which hemisphere he wouldn't want to be without.
GAZZANIGA The old phrase around our lab is 'don't leave home
without your left hemisphere.' That's where the action is.
REMEMBERING WHAT MATTERS
ALAN ALDA (Narration) The clarinet player is Jim McGaugh;
the tune, "As Time Goes By"; his passion, the mind and how
it is shaped by memory.
McGAUGH Everything that we do as humans depends upon our
memory. Your notion of your own past is nothing but a memory
in your brain - something changes in your brain. You and I
live in a world which is about a half a second long - that's
the immediate experience. And what happened two minutes ago
that you think is still here is gone, except in your brain.
ALAN ALDA (Narration) This rat at the University of California,
Irvine, is about to get a better memory, thanks to Jim McGaugh.
There's food at the end of four of these arms. Entrances to
each of the other four are blocked by a plastic window. Once
the rat has eaten the available food, the windows are removed
and food placed in the previously blocked channels. After
several trials, the rat learns to enter only the newly opened
arms, ignoring the old ones it had already cleaned out. Eighteen
hours later, however, the rat has forgotten the secret and
checks out the old arms as well as the new. But this rat is
getting some help - a shot of adrenaline immediately after
learning the task. This time, after an eighteen-hour absence,
his memory of the maze was is good as new.
RESEARCHER He remembered where he had been before and only
went to the arms that he hadn't been to, so he performed the
task very well, perfectly, one hundred percent performance.
ALAN ALDA (Narration) Adrenaline is the hormone behind the
"fight or flight" response - the surge of energy we and other
animals get when we're threatened. Jim McGaugh's experience
with rats suggests the adrenaline rush is doing more than
allowing us to run fast.
McGAUGH It also would be a very good a idea to be able to
remember where the predator was and what happened so the next
time the animal would be able to avoid the situation or minimize
the probability of being eaten the next time. So the same
hormones which were involved in generating the fight or flight
response we now have discovered work on the brain to make
ALAN ALDA (Narration) So what would happen in a stressful
situation - which for rats means having to swim - if somehow
adrenaline is removed from the picture? This rat is trying
to find a transparent underwater platform. Eventually he has
to be shown where it is. He's tested again three days later
- and this time his memory guides him to the platform quickly.
Like his colleague, this rat has also been shown the platform.
But moments later, he gets an injection of a drug - a betablocker
- that blocks the effect of adrenaline. When this rat's tested
three days later, it's as if he's never been here before.
So for rats, adrenaline seems central to making stronger memories.
But what about the rest of us?
McGAUGH What we need to do is to have....
ALAN ALDA (Narration) Jim McGaugh is collaborating with Larry
Cahill on an experiment that involves a single set of slides
telling two very different stories.
McGAUGH A boy and a mother leaving home - they're going to
visit ah... father who works in a hospital.
ALAN ALDA (Narration) A subject is told his emotional reactions
to a story are to be measured. In fact, this device isn't
hooked up to anything.
CAHILL (talking off-camera) OK, a mother and her son are
leaving home in the morning.
ALAN ALDA (Narration) The story he hears is bland.
CAHILL She is taking him to visit his father's workplace.
The father is the chief laboratory technician at a nearby
ALAN ALDA (Narration) It concludes with mother and son coming
across a fake car accident being used in a training drill.
CAHILL Special make-up artists were able to create realistic
looking injuries on actors for the drill. OK, that was very
good, now the last thing I would like you to do today is to
rate your emotional reaction to the story you just saw on
a scale of zero to ten.
SUBJECT Probably about a two.
ALAN ALDA (Narration) This subject is hearing a very different
CAHILL ... while crossing the road the boy is struck by a
runaway car which critically injures him. Specialized surgeons
were able to successfully reattach the boy's severed feet.
I would like you to rate your emotional reaction - your personal
emotional reaction - to the story you just saw.
ALAN ALDA (Narration) Two weeks later, the subjects are given
a surprise memory test.
CAHILL You were told that the father's occupation is: a school
teacher, a surgeon, a laboratory technician, a hospital custodian.
SUBJECT 2 A laboratory technician.
ALAN ALDA (Narration) Memories of the emotional story are
CAHILL Next question. You were told that the father's occupation
ALAN ALDA (Narration) memories of the boring story, poor.
Subject 1 I think it was the hospital custodian.
ALAN ALDA (Narration) So far so good. But is it adrenaline
that's making the difference? This subject is taking a betablocker
to block adrenaline right before getting the emotional version
of the slideshow.
CAHILL While crossing the road, the boy is struck by a runaway
car which critically injures him. At the hospital the staff
prepare the emergency room...
ALAN ALDA (Narration) He still rates the story as highly
emotional. Subject 3 I'd say about a seven.
CAHILL Seven? OK, very good.
ALAN ALDA (Narration) But when he's tested two weeks later,
his memory is as poor as those who heard the bland story.
CAHILL ... a surgeon, a laboratory technician, or a hospital
SUBJECT 3 Um... surgeon.
CAHILL Surgeon? OK...
CAHILL (to camera) Despite the fact that their emotional
reaction to the story a week earlier had been normal, they
didn't experience the enhanced memory associated with the
emotional reaction that the placebo controls did. So what
we seem to have done - what we think we have done - is we
snapped the relationship between an emotional reaction and
enhanced long-term memory.
ALAN ALDA (Narration) The Irvine team is now trying to pin
down the relationship between emotion, adrenaline and memory
by looking inside the brain as a memory is formed. Shannon
is left alone to watch thirty minutes of unpleasant images
while glucose is injected into her bloodstream. This machine,
called a PET scanner, produces an image of Shannon's brain
revealing where most of the glucose was being used, and so
which parts of her brain was working hardest, while she was
watching the films. And the region that was most active is
an almond-sized structure called the amygdala. What's more,
in tests like this with several subjects, the brighter the
amygdala, the better their memory of the film three weeks
later. It's the beginning of an explanation, Jim McGaugh believes,
of why we remember emotional events. Activated by the hormones
the emotions produce, the amygdala sends a message to the
rest of the brain as if to say: this information is important
- don't forget it.
McGAUGH Life goes by, trivial things happen to us, important
things happen to us. Now, it would make a lot of sense, wouldn't
it, because we have a brain that probably has some limited
capacity of some kind, wouldn't it be nice to have a brain
which stored to a more intense extent those things that are
important and to a lesser extent those things that are trivial.
We... we have a brain that does that. And it's emotions that
create a relationship between the importance of an event and
how well we remember that event.
TRUE OR FALSE?
ALAN ALDA (Narration) What I didn't know one pleasant morning
while strolling with Dan Schacter was that - in collaboration
with my scheming producers - he was setting me up for a test
of my memory.
SCHACTER Now we're just going to witness a... simple picnic
scene and we want you to pay attention to how often either
of the folks gets up and down. So whenever someone gets up
and down you just make a mental note of it.
ALAN ALDA OK.
ALAN ALDA (Narration) I knew Dan Schacter to be a noted memory
researcher. But this picnic was a surprise.
ALAN ALDA Oh good, I love to watch people eat.
ALAN ALDA (Narration) Although Dan had told me to keep track
of how many times the picnickers stood up, I suspected there
was more to this little scene than that. But what? I wasn't
to find out for another two days that the picnic was part
of a carefully choreographed attempt to implant false memories
into my brain - to make me "remember" as real things I'd never
seen. At the time it was like trying to keep track of a very
bad play while sitting uncomfortably close to the author.
After ten bewildering minutes, the picnic - mercifully - came
to an end.
ALAN ALDA Bravo. Very nice, very nice.
SCHACTER We could have used a little more high drama here
ALAN ALDA Yeah, but it doesn't lack for slowness.
ALAN ALDA (Narration) At this point I was politely asked
to leave. The scene was played over for a stills photographer.
But this time it included things that never happened while
I was there. Which meant I also missed Dan Schacter's basic
premise: that memories are malleable.
SCHACTER One of the things that we know about memory is
that it's not fixed at the original experience we have. The
way we talk about the event later uh... the way we think about
it uh... can effect, improve or sometimes change our memory
and photographs are one everyday source of reviewing past
experiences that may have a potent effect on memory and we're
interested in exactly what that effect is.
ALAN ALDA (Narration) Two days later I was in Dan Schacter's
office at Harvard University, looking at photographs.
SCHACTER ... is it well cut-out, is it well centered? For
each photo I'm gonna ask you for a one to five rating.
ALAN ALDA Oh... heh heh, part of me is trying to figure out
what this is really a test of. I'd have to say, you know,
four to four point five. This is a nicely composed picture.
ALAN ALDA (Narration) I didn't believe this rating ploy for
a moment, but graciously played along - even when the photos
where of things I knew I hadn't seen.
ALAN ALDA I take it you don't want me to mention whether
or not this is a picture of something that happened or not,
because this never happened.
SCHACTER Right, we're not concerned with that right now.
We're just concerned with...
ALAN ALDA ... showing how smart I am.
ALAN ALDA (Narration) In all I looked at about twenty photographs.
Finally the moment I'd been anticipating... ... the test.
SCHACTER... the fishing pole?
ALAN ALDA No.
ALAN ALDA (Narration) The question is: did I see these things
at the picnic or not?
ALAN ALDA No umbrella, no.
SCHACTER Potato chips?
ALAN ALDA No. The potato chips were in the picture. Well,
I remember them in the picture but I don't remember them on
ALAN ALDA (Narration) I was doing fine until...
SCHACTER Nail file?
ALAN ALDA Yes I think I remember her filing her nails, although
the picture is also vivid in my mind. But I think I remember
her filing her nails, too.
ALAN ALDA No kite. No, there was no kite. There was a kite
in the picture but that's it.
SCHACTER OK. A man's cap.
ALAN ALDA (Narration) By now it was obvious that Dan was
trying to confuse my memory of things I'd seen for real...
ALAN ALDA I think he wore a cap.
ALAN ALDA (Narration) ... with things I'd only seen in the
ALAN ALDA Well, see... I think he was wearing a cap in the
photographs and I think - and I remember when I looked at
the photographs - there's something wrong with this picture.
I don't think he wore a cap.
SCHACTER A bottle of water?
ALAN ALDA Yes, there was a bottle of water.
ALAN ALDA (Narration) Oh, oh, this would come back to haunt
SCHACTER Folding chairs?
ALAN ALDA No!
SCHACTER No, no way. Pasta?
ALAN ALDA Yes! You think I could forget pasta? Come on!
SCHACTER It's over.
ALAN ALDA That's it?
SCHACTER That's it. It's out of your system.
ALAN ALDA So it had nothing to do with how many times they
SCHACTER Well, that was just to get you to pay attention
to what was going on in front of you.
ALAN ALDA Yeah, that's why I paid attention to everything
else. Now what I'm really interested to know is, were you
able to place in my memory things that never occurred in real
ALAN ALDA You did? You did?
SCHACTER We did. Even though um... even though we... you
know, we told you, you knew what the game was. You knew that
some of things that we were showing you in the photographs
had never happened. Despite that...
ALAN ALDA This is horrible.
SCHACTER One was the nail file.
ALAN ALDA Yeah.
SCHACTER That was only in the photo.
ALAN ALDA You know, when I first saw the nail file there
was this little uncertainty - was that real or wasn't it -
and then a second later, I was... I was sure I'd seen it.
ALAN ALDA (Narration) In the final tally, of eight things
that appeared in the pictures only, I wrongly remembered two
as having been at the picnic - the nail file and a bottle
of water. The photographs had somehow lodged in my brain right
along with my memory of the picnic itself and I couldn't tell
which was which. To understand how this can happen means we
have to first understand where in the brain memory is located.
ALAN ALDA Is it possible to point to some place on the brain
and say that's where memory is?
SCHACTER Well, there's no one place - there's no one place
I can point and say 'there's your memory of high school graduation
and.. and there's your memory for having eaten breakfast yesterday.
Instead of being in one place, many of believe that memory
is kind of scattered in different parts of the brain.
ALAN ALDA (Narration) The idea is that memory consists of
all the bits and pieces of an experience - the sights, the
sounds, the emotions - with each fragment stored in areas
of the brain responsible for handling that particular sensation.
So sounds are stored in the auditory cortex; sights in the
visual cortex and so on. Keeping track of what's where is
a region of the brain called the hippocampus, which functions
as a sort of index for our memories. Recalling an event means
re-assembling all those bits and pieces. It's not like replaying
a videotape. It's more like shaking a kaleidoscope, with every
shake - every recall - the pieces fall together anew - sometimes,
as in my memory of the picnic, including bits that don't quite
belong. Dan Schacter recently wondered if he could tell the
difference between real and false memories by peering into
the brain while it was remembering. Twelve people heard word
lists like these, and had to remember as many of the words
as they could.
ALAN ALDA Writer... um...
ALAN ALDA (Narration) What's sneaky about the lists is that
while they're each united by a theme, they don't contain more
SCHACTER Bed, rest, awake, tired, dream, wake, snooze, blanket,
doze, slumber, snore, nap, peace, yawn, drowsy.
ALAN ALDA Sleep, doze, bed...
ALAN ALDA (Narration) There - right off the bat I said "sleep",
but sleep wasn't on the list. Again, I'd been given a false
ALAN ALDA ... ah, bed...
ALAN ALDA (Narration) The twelve experimental subjects all
got PET scans while doing this test. What's fascinating is
that recalling both true and false memories mostly involved
the same bits of brain, especially the hippocampus - the index
region. But while the true memory lit up the auditory cortex,
the false memory didn't. So even though the subjects reported
hearing the words that weren't there, their brains appear
to contain no trace of the sounds of the words.
ALAN ALDA So in a way you really can look inside somebody's
brain and tell whether they're having a true memory or a false
memory under certain conditions.
Schacter Under certain conditions. Within this one experimental
paradigm group of twelve people we were able to see, ah, some
differences between true and false recognition.
ALAN ALDA (Narration) Dan Schacter emphasizes there's a long
way to go before this first faint trace of a false memory
could be turned into a practical test that could be used,
for instance, in a courtroom. Meanwhile, discovering how easily
my memory can be tricked was lesson enough.
ALAN ALDA What I think this really brings home to me is it's
very important to say not 'this is what happened' but 'it
seems to me that I remember this is what happened.'
SCHACTER I think that's a very important lesson.
WHAT'S IN A DREAM?
ALAN ALDA (Narration) My brain is about to enter an altered
state of consciousness - at least, that's the plan.
ALAN ALDA Hello... I sit here?
ALAN ALDA (Narration) All I have to do is go to sleep. Holmes
OK, he first that we're going to be doing tonight is putting
electrodes on so we can measure your electrical activity and
know your stages of sleep.
ALAN ALDA What's that? Holmes It's called calodian, it's
very similar to airplane glue. And what this...
ALAN ALDA (Narration) Airplane glue in my hair... as it turned
out only the first of several indignities that lay ahead during
my night as a research subject at Harvard University's Sleep
ALAN ALDA I don't want to rush you, but I'm falling asleep.
Holmes Are you really? Good.
ALAN ALDA (Narration) The study I'm joining is to find out
what happens to our minds while we're dreaming.
HOLMES OK, and that's the last electrode.
ALAN ALDA (Narration) Like most people, I've always been
fascinated by dreams - my own especially. How do our brains
come up with that stuff? Even more interesting - why? My night
began with a test of the state of my brain. The task is to
spot if the second of two words flashed on the screen is a
real one. Sometimes the second word seems to be related to
the first. When it is, and my brain makes the association,
then I'm usually able to decide if the second word is real
or fake more quickly. So by measuring my reaction time, the
test can tell how good my brain is at making associations.
ALAN ALDA Bed... bed.
ALAN ALDA (Narration) The only association I was interested
in right then was between bed and sleep - not so easy when
you know a stranger is eavesdropping on your brain.
HOLMES Alan, I need you to lie quietly with your eyes closed.
OK, if you could blink five times, slowly...
ALAN ALDA (Narration) This is to check the electrodes near
my eye. They'll be looking out for REM - R.E.M. - the rapid
eye movements we all make when we dream.
HOLMES Great. OK, you're all set. You can go ahead and get
comfortable and have a good night's sleep.
ALAN ALDA (Narration) So if you'll excuse me, I'll leave
you in the care of Jen Holmes while I try to sleep with wires
pasted on my face and glued to my scalp.
HOLMES Now he's moving, getting comfortable and you'll typically
see some kind of movement when people first start to fall
asleep. The top two lines represent his eye movements, and
this gentle rolling is also typical of falling asleep. The
next lines down are his brain waves, and we see that as he
falls into real sleep they start to get spikier. He's now
officially asleep. Our experiment calls for him to do the
word association test several times during the night, one
of them when he's asleep but not dreaming. That's what's happening
now, so I'll go wake him up.
ALAN ALDA Yep... nope... oh, I'm falling asleep here. I am
not checking into this hotel again.
ALAN ALDA (Narration) Well, after that my night went to pieces.
Every time I drifted off and started to dream I'd think, oh
good, I have to remember this - and promptly wake myself up.
By six in the morning, Jen had been joined by her boss, Bob
Stickgold, and it began to look like we weren't going to find
out what my brain does when it's dreaming. Stickgold Since
about, ah, 2:30 this morning he's been having a hard time
sleeping. Uh, he'll go to sleep - he'll sleep for ten of fifteen
minute series - you can hear the pens slapping around - he's
rolling around in bed now. He's been doing that for hours
ALAN ALDA (Narration) But then, when it was almost too late,
I began drifting into a dream. Stickgold If we wake him up
right now we've got an eighty-five percent chance - a ninety
percent chance - of getting good REM reports. So what we want
to do is wait until it gets another burst - there's some more
right there, look at these, these are really good eyes movements,
these are fast and they're big. So, I think we should go in
there now and see what we can get.
ALAN ALDA I was... uh, being propelled the solar wind but
the wind wasn't behind me, I was going toward the sun. And
I was flying over Berlin and I remember thinking that this
was, uh... called uh... 'Nightgown Over Germany.'
STICKGOLD It's only about six-thirty, it's still early.
ALAN ALDA Oh, it's still early. Well, let's try it.
STICKGOLD Let's try it. OK. Pleasant dreams.
ALAN ALDA (Narration) With one dream in the bag, I felt better
about trying for another... So that once again I could be
awakened for that exciting word association test.
STICKGOLD So, how does it feel to you that you slept?
ALAN ALDA How did it feel that I slept? I had a worse night
of sleep at a truck route in New Zealand.
ALAN ALDA Yeah...
ALAN ALDA (Narration) By now all I wanted was a little breakfast
and the airplane glue out of my hair. But I was also curious
of course about the tests I'd been taking. What did they have
to do with dreaming? Most dream researchers believe that during
REM sleep the normal signals to the brain from our bodies
are cut off. Instead of receiving inputs from our eyes and
ears, the visual and auditory centers are flooded with signals
surging up from the more primitive regions of the brain. These
signals, the theory goes, are completely random and meaningless.
But dreams, of course, seem to make sense - at least at the
ALAN ALDA ... the wonderful part about it was I went out
through my nose, see? So then I had all these words I was
ALAN ALDA (Narration) So the key question is, where do the
stories of our dreams come from? According to Bob Stickgold,
we simply make them up as we go along.
ALAN ALDA I'm a little thick this morning because I... I
had this funny night sleep. I still don't quite get how you
arrive at the conclusion that something in the brain is supplying
story and meaning and uh... uh... a coherence to...to these
random images... and not that they're coming up in a more
coherent way already.
STICKGOLD If you look at your dream, I mean there you have
the start of - gee, it's going to be an out-of-body experience,
and first of all it goes out through your nose. I... I'm sorry,
it's just hard for me to believe that someone scripted that
for you to do. You were just thinking 'out-of-body, how am
I going to get out of body, help me somebody how can I get
out-of-body' and something in your brains says 'oh your nose.'
ALAN ALDA (Narration) So during dreaming, our brains are
scrambling to make sense of nonsense. Here's where the word
tests are revealing - because subjects woken from REM sleep
are quicker at making associations between words than when
woken from non-REM sleep - or even when they are wide awake
during the day. It's as if during REM sleep our brains are
primed to put together stories from random images and feelings.
STICKGOLD Our guess is - and it's truly just a guess at this
point - is that the brain is just trying to keep up with these
random inputs and trying to use everything it knows to make
some kind of sense out of it.
ALAN ALDA (Narration) That might be how we dream. But it
still leaves the question of why. This experiment, being conducted
in the sleep lab at Trent University near Toronto in Canada,
is suggesting dreaming helps us learn.
SYLVESTER OK, you're all set. We'll see you in the morning.
ALAN ALDA (Narration) Lara Sylvester is spending four nights
of her summer vacation here. At least she gets to sleep in
peace. The aim of the study is to see how active her eye movements
are during dreaming while she's in a relaxed, summery frame
of mind. Recording and counting her eye movements is researcher
Carlyle Smith. Summer's over and Lara is studying hard for
her final exams. Now her brain is in high gear, right up through
the finals themselves. Her mind still buzzing from all that
learning, Lara again gets to sleep in the lab. And now the
number of rapid eye movements during her dreams is strikingly
different. Carlyle Smith For some people there's almost a
doubling of the number of eye movements after they've had
intense learning activity then when they've been just in uh..
ALAN ALDA (Narration) This discovery led Smith to wonder
if the extra eye movements during learning are useful. Do
these apparently more intense dreams actually help us learn?
So he set up an experiment to see if learning a complicated
logic game was affected by how much dreaming a person does.
The game is baffling enough to explain let alone play, but
it involves making letter combinations according to complex
STICKGOLD... J... ... or E to start of with so you can then
make one final, gigantic, messy whiff.
ALAN ALDA (Narration) The game is a tough test of logical
thinking. The students' skills at the logic game were tested,
and then they were then given a much simpler memory test.
After seeing pairs of words they were shown one of them and
had to remember its partner. Then some of the subjects - this
isCatherine - got to have a night's sleep almost as bad as
mine. Researcher What we're trying to do is deprive them of
two REM periods. So, once she goes from Stage Two to REM sleep
I will go in and wake her up.
CATHERINE Good morning.
ALAN ALDA (Narration) Once woken, Catherine is kept awake
for five minutes by a math task, to make sure she doesn't
slip back into her dream. Other students were the experiment's
controls, either being awakened when they weren't dreaming...
RESEARCHER You need to get up for a few minutes.
ALAN ALDA (Narration) ...or getting to sleep through the
night in peace. A week has passed, and it's time for the memory
test again. Catherine, deprived of dreams, doesn't do as well
as she did before - but then, nor do any of the subjects,
even those whose night was undisturbed. But then came the
logic task. And this time there was a significant difference
between the dream-deprived and the dream-indulged.
SMITH Any task where it seems to be just straight memorization
that's involved... uh, don't appear to be vulnerable to sleep
loss - REM sleep loss. Tasks where some kind of more uh...
understanding is involved you not only have to memorize some
rules but you have to be able to apply the rules, that kind
of material uh, is vulnerable to REM sleep loss.
ALAN ALDA (Narration) Carlyle Smith now took a daring leap.
What if people could be somehow prompted to learn during dreaming?
A new batch of student volunteers hear a loud clock while
learning the logic game. When they are tucked in for the night,
some of the subjects subjects now wear earphones. And whenever
their eyes are darting most rapidly, they get to hear ticks
reminiscent of the clock. The idea is to see if the ticks
remind the dreamer of the learning task right in the middle
of her dream. The results were startling. Students who heard
ticks during active eye movements proved far better than controls
in learning the logic task, suggesting that being reminded
of a problem during dreaming helps us tackle it. All in all,
finding out that not only is my mind more capable of mental
leaps when I'm dreaming, but that I might actually be doing
something useful with that ability, made my night at the sleep
lab seem worthwhile - at least in retrospect. It is nice to
know that something we spend perhaps a tenth of our lives
doing is more than simply nightly entertainment.
OLD BRAIN - NEW TRICKS
ALAN ALDA (Narration) For our final story I'm once again
having my head examined, this time in the lab of Helen Neville
at the University of Oregon, Eugene.
ALAN ALDA You know I think after this show a lot of people
will be wearing these. Neville We've had many requests for
extra hats after our subjects see how fetching they are.
ALAN ALDA Yes, so a lot of people want to wear them out in
the street? Neville Oh, absolutely.
ALAN ALDA Cute little suspenders. Are we afraid my helmet
will like whip off if I turn my head too fast? Neville When
we turn the propeller on we want to make sure you don't go
ALAN ALDA I'm going to ask you some dignified questions while
I'm wearing this.
ALAN ALDA (Narration) Now a special gel is added to each
of the thirty two electrodes in the hat.
ALAN ALDA F7... OK.
ALAN ALDA (Narration) The gel helps make electrical contact
between the electrodes and my head.
ALAN ALDA ...too high.
ALAN ALDA (Narration) It has to be firmly worked into place
to be effective.
ALAN ALDA Well I think you drove the gel right into my scalp...
direct contact with neurons... get a very good reading. Sixty-two
point nine - I guess it's time to jam another Q-Tip in my
ALAN ALDA (Narration) That was the warm up, but for the actual
experiment I'm going to have to plug in... get comfortable...
ALAN ALDA Want me to hold this? Researcher No, that's fine.
Neville We're going to check first that we have good contact
from all the electrodes and that we can see good, clean signal
out of your head. And then we'll begin with the experiment.
ALAN ALDA OK. I'll just relax.
ALAN ALDA (Narration) When they're listening in on brain
waves, neuroscientists like Helen have to get their subjects
to reduce muscle activity to a minimum, so the faint signals
from the brain can come through. Neville OK, Alan, this looks
really good. Keeping your eyes nice and still, your muscles
are really relaxed - keep that up.
ALAN ALDA (Narration) Helen studies where in the brain we
process language. My task is simply to follow each sentence
and register whether or not it makes sense. That one seems
OK. Here's the next. Sue-- shared -- her -- candy -- with
-- her -- best -- boat. Well that's nonsense. But actually
the task itself isn't important -- it's just to hold my attention.
In fact the system is continuously checking every electrode
to look for tiny changes that might coincide with each new
word flashing up. Averaged over hundreds of subjects, these
signals show where in the brain different words are processed.
The result is fascinating. Vocabulary words, like light --
daytime -- candy -- boat -- are processed in several different
places in both left and right hemispheres. But grammar words,
her -- with -- the -- in, are concentrated in parts of the
left hemisphere. So for language, different parts of the brain
have different jobs. That's true, at least, for adults. The
question Helen Neville asked was, is the same true for children?
Fourteen-month-old Dassi is at the stage of life when we rapidly
acquire language. To find out what's going on in her brain,
she needs to put on that charming hat with the electrodes,
this time in a fetching shade of green. Dassi, however, has
other ideas. I can't say I blame her. Well how about a blue
one? Or maybe yellow will do the trick. Fortunately Davi,
her brother, couldn't see what all the fuss was about. With
stuffed animals to hold his attention, he settled down to
listen to a series of words, while the system measured his
brain's response. [Bottle... carbon... cat... diaper]
ALAN ALDA (Narration) The result, once again averaged over
many subjects, looks completely different from the adult pattern.
Very young children process language all over the brain. But
then pretty soon, by about age four or five, the typical adult
specialized areas have developed. This kind of result has
important implications for education in general.
ALAN ALDA Are there things we should be doing sooner when
we educate children? Neville We don't know when the critical
time windows are, when learning math, learning music. learning
science - adult-kind of learning - would be optimized. I don't
have any doubt that there are such critical window of opportunity.
We just need to do the research to determine when they are.
What we do know is that from the point of view of language
learning, early is better.
ALAN ALDA (Narration) For people who learn more than one
language, the early locking in of the brain's language areas
makes a big difference. Arthur Goh, for example, speaks fluent
Chinese and English Researcher Where were you born? Goh Uh...
Singapore. Researcher How old were you when you started learning
English? Goh About three or four. Researcher So in school...
Goh Uh huh, in school.
ALAN ALDA (Narration) So while English is Arthur's second
language, he learnt it when still young. When he's tested,
his brain's response to English is indistinguishable from
that of a native English speaker, with the same specialized
areas for grammar and vocabulary. Researcher Where were you
born? Goh I was born in... Viet Nam.
ALAN ALDA (Narration) English is also Nick Hong's second
language, but he didn't start learning it until age 10. And
when responding to English, his brain looks different -- there's
no single grammar area. Nick ran up against a limit that confronts
all late learners of languages.
ALAN ALDA In my case I... I started studying French in my
teens, I got really serious about it in my late teens... I...
I... thought I could speak it pretty well. What.... what were
the things limiting me? Neville The sound of the language
and the grammar of the language are the parts of the language
that suffer most from delayed learning of a language. So you
probably speak with an accent in French - people will probably
tell you that. And your grammar probably isn't perfect. On
the other hand you probably have a huge vocabulary.
ALAN ALDA (Narration) Nobody who learns a language after
childhood can expect to speak it perfectly. [Poem]
ALAN ALDA (Narration) So don't blame the speakers -- for
grammar and pronunciation, at least, you can't teach an old
brain new tricks. [Poem]
ALAN ALDA (Narration) Back in the lab I met another of Helen
Neville's test subjects, Dean Gabel.
ALAN ALDA When did you learn to sign? Interpreter I learned
when I was four years old.
ALAN ALDA What brought that about? How did you learn to sign?
Interpreter When my parents found out that I was deaf - they
found out that when I was two - and they decided to send me
to the deaf school when I was four years old and there is
where I learned to sign.
ALAN ALDA (Narration) When Dean's response is tested in the
same way as for a spoken language, the result looks like that
of any other first language, with typical grammar and vocabulary
areas. That makes sense, because he learned sign language
while still young. But take a look at this. It's a peripheral
vision test, in which Dean has to detect the flashing squares
on the edges of the screen, while concentrating on the one
in the center. When his brain response is mapped, it shows
he's using both the normal vision processing area and a large
section usually devoted to sound. Of course vision takes on
critical importance when you're deaf. When I took the same
test my peripheral vision wasn't as good as Dean's, and I
didn't use that extra processing area in the brain. This is
the flip side of development in the young brain-- not only
is it locking in particular parts for specific functions,
but it can also invent new uses for sections if necessary.
ALAN ALDA That's just amazing... that you've got this kind
of uh... that the brain is kind of malleable like a piece
of clay in a way - it's not so hard and fast as uh... as uh...
at least I thought it was.
NEVILLE That's right. There's no doubt about the fact that
there are very strong biases, or likelihoods according to
which the brain will develop. That's why in ninety-nine point
nine percent of the people this visual brain, this is auditory
brain, this is the part that's important for touch, this is
the part that's important for language - but these strong
genetic biases can be changed - they can be modified within
limits, within time limits. [This is a sheep's brain.]
ALAN ALDA (Narration) Our knowledge of what's going on inside
NEVILLE This is the brain of a cat.
ALAN ALDA (Narration) ...cats', sheep's or people's -- is
NEVILLE This is a human brain and we've cut it in half...
ALAN ALDA (Narration) It's easier to explain the processes
taking place in the distant stars than in our own heads.
NEVILLE Right above the ears is important for hearing...
ALAN ALDA (Narration) That's one reason Helen likes to talk
to school kids about what we do know. Great challenges exist
in neuroscience. We don't yet understand how three pounds
of tissue produce consciousness -- how our brains turn into
our minds, and into our selves.. The brain may be the final
frontier of science -- waiting to be crossed by tomorrow's
scientists. Kid 1 ... like making decisions.
KID 2 ... the left side is for controlling your right side.
NEVILLE There's a lot more of the brain that we didn't talk
about. That's because scientists don't by any means know what
all the different parts of the brain do. That's why maybe
some of you guys will grow-up to be brain scientists. Because
there's... the most complicated structure in the universe
that's gonna take a lot of people to figure out how it works.