Alan Alda intereview with Michael Gazzaniga
Featured on "The Man with Two Brains,"
from the Scientific American Frontiers special
"Pieces of Mind."
Episode Opening
The Man with Two Brains
Remembering What Matters
True or False?
What's in a Dream?
Old Brain/New Tricks
EPISODE OPENING
Alan Alda: We'll start with a man with two brains.
Then we'll peek inside a brain while it's storing a
memory.
We'll discover how easily memory can be
fooled...
And eavesdrop on my brain when I'm dreaming.
Alan Alda (Narration): We've gone to
extraordinary places and done extraordinary things
in making Scientific American Frontiers, but
there's nowhere we've visited that's more
extraordinary than our destination now: inside the
human brain.
This brain is now no more than three pounds of
preserved tissue, but once it held a mind. A mind
that was filled with a million memories - of a first
ice-cream cone, a vivid sunset, a bicycle, a kiss. It
learned a language, maybe two or three. It felt
rage, pain, joy, fear, love - it dreamed of flying, of
falling, of forbidden things. For the briefest
moment it experienced death.
We still know almost nothing of how the brain
works. But in the next hour we'll visit with
researchers who are finally beginning to see
inside the brain while it's dreaming, and thinking,
learning and remembering.
You're in for an experience which could change
your brain forever.
THE MAN WITH TWO BRAINS
Alan Alda (Narration): We began our journey into
the human brain here, on the campus of Dartmouth
College in New Hampshire.
I'd come to meet one of the world's leading brain
scientists, Mike Gazzaniga, and a man he's worked
with for over a decade: A man with two brains.
Alan Alda: You've been working a long time with
Dr. Gazzaniga?
Gazzaniga: Fourteen or fifteen years.
Joe: Huh... it doesn't seem that long.
Alan Alda (Narration): The collaboration began
when Joe had surgery.
Alan Alda: And you had this procedure to ah...to
ah...correct an epileptic problem, is that right?
Joe: Yeah, to try and stop the seizure. I was having
seizures like everyday or so, or sometimes two or
three a day.
Alan Alda (Narration): To control Joe's epileptic
seizures, a surgeon severed the connection
between the two halves of his brain. Cutting the
corpus callosum like this prevented the spread of
the electrical storms that caused his seizures. But
it also prevented the left and right halves of his
brain from communicating with each other.
In the years since the operation, Joe's epilepsy has
been under control. He now earns a living at an
egg farm, and in his everyday life is largely
unaffected by the fact that his left and right brains
work independently.
Alan Alda: Do you feel any different when you
think about something than you did... differently
from the way you felt before the procedure?
Joe: No... it's just kind of a back-up brain is all.
Alan Alda: ... that's something everybody could
use, right?
Alan Alda (Narration): I found out how true that
was right away when I was asked to draw a
different shape with each hand.
In a brain like mine - roughly speaking normal - at
least all in one piece - the left half of my brain
controls the right side of my body while the right
brain controls the left side.
Alan Alda: Oh no!
Alan Alda (Narration): But because the two
halves are connected...
Alan Alda: Nothing wrong with that!
Alan Alda (Narration): ...getting each hand to
work independently isn't easy.
Gazzaniga: Well, we're seeing the fact that... that
Alan's hemisphere's are connected.
Alan Alda: Yeah!
Gazzaniga: That the uh... motor messages from
one are confusing the motor messages in the other.
Alan Alda: I was just drawing an upside down
duck.
Alan Alda: (Narration) But when Joe is given the
same task, his two hands operate as if controlled
by two separate brains.
What's happening is that each half of Joe's brain is
given a separate instruction. He is asked to fix his
eyes on the cross in the center of the screen,
Anything flashed to the right of the cross goes only
to his left hemisphere. Things to the left go to his
right hemisphere. Because the two don't
communicate, each hand does only what its half of
the brain sees.
Alan Alda: Wow, look at that. It's really like two
different people doing the same...
Gazzaniga: That's right...
Alan Alda: ... same task.
Gazzaniga: ... that's the idea.
Alan Alda (Narration): In an experiment that's
now a classic in brain research, Mike Gazzaniga
over thirty years ago used a similar set-up to find
out if the two halves of the brain are specialized to
do different things.
Joe: Ship.
Alan Alda (Narration): Joe is being flashed a
word only to one half of his brain. Words flashed
to the right...
Joe: Storm.
Alan Alda (Narration): ...are seen only by his left
brain - and Joe can report seeing those words just
fine.
Joe: Piano.
Researcher: Good.
Alan Alda (Narration): But when a word is
flashed to his right brain...
Joe: Didn't see that.
Researcher: OK. Joe I'm gonna ask you...
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 secret communication...
Gazzaniga: That's right.
Alan Alda ... and now he knows that it's a
telephone... up until then he was blind to it.
Gazzaniga Exactly.
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 was coming.
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 the secret.
Alan Alda That's great. That's really interesting.
And if he had seen that with the corpus callosum
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?
Joe Music.
Researcher Music?
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 seemed pleased...
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 that face.
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.
(Click here to read an additional transcript of a
conversation between Alan Alda and Dr.
Michael Gazzaniga.)
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 stronger
memories.
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 hospital.
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.
Cahill OK.
Alan Alda (Narration) This subject is hearing a
very different story.
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 good...
Cahill Next question. You were told that the
father's occupation is...
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 custodian.
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.
part 2:
Alan Alda: What we've seen while filming this
story for Frontiers is really different from the
picture that we have popularly of the left and the
right brain, isn't it?
Michael Gazzaniga: Absolutely.
Alan Alda: What is the popular notion, and how is
that different from what you know about the brain?
Michael Gazzaniga: Well the initial popular
notion was that you should look at the right
hemisphere as the intuitive part of your brain - the
part that's going to give you great insight into the
world, be the painter, the poet and all this sort of
thing. And the left brain was the engineer, the
analytical part. Well, like everything, there's a
little grain of truth to it, but it is way overdone.
It is the left hemisphere that's the problem-solving,
rational system in the brain - there's no question
about that. But the right hemisphere's capacities
are really quite limited to special skills, as we
saw in the facial experiment on Frontiers, and
other experiments we didn't show on the program.
But the right hemisphere can't think well at all. It's
problem-solving capacity is very limited, it's
hardly intuitive. It is hardly a powerful mental
machine. It is the left that's the powerful mental
machine, and why this idea took off into the
culture and became so popularized is something
for a sociologist to figure out. I think everybody
felt like they understood something about the
brain, and it just became sort of a "cocktail kind of
knowledge." But the basic popularization was not
good.
Alan Alda: So if somebody is standing there with
a cocktail and says, "I'm really very
right-brained," what are they really saying about
themselves?
Michael Gazzaniga: They're lame-brained.
They're not reading the recent work. No, what
they're trying to say is, of course, that they feel
they're intuitive. They feel they can only represent
the world in symbols like painting or maybe
music, and they're not this irrational system. And
there's all kinds of styles. We know people who
are highly rational and people who seem to be
very spontaneous and intuitive. But don't put a
piece of brain tissue to that dichotomy. It's much
more complex than that.
Alan Alda: Does the right brain mostly just take in
a picture of what's going on, so the left brain can
analyze it?
Michael Gazzaniga: No. The right brain takes in
a part of the sensory world. It takes in half of it.
But it relays that information to the left, and the
left takes in its own half, and the two get
combined, if you're doing a problem solving task,
in the left hemisphere. But just as well, the right
brain is taking information from the left. If a face
pops up in the right visual field, it's probably
transferred over to the right hemisphere, via the
corpus callosum for true detection.
Alan Alda: So all the sensory input is the same on
both sides?
Michael Gazzaniga: The basic sensory input is
the same in both hemispheres; the motor output is
the same. There are devices that work on the
sensory input that seem to be lateralized, like the
facial detector we talked about and saw. So when
we speak of lateralized processes of the brain,
they're very real. But you have to be very careful
about what you're talking about. Are you talking
about specific processes that deal with particular
items, like facial and information? Are you talking
about rational processes? Problem solving? Then
you're talking about the left hemisphere again. Not
the right intuitive hemisphere.
Alan Alda: Dividing the brain into two
hemispheres like this - is this something that
occurs in most animals, or just at a certain level of
organization? Does it happen in insects and
lobsters and worms? At what point do you begin
to see it?
Michael Gazzaniga: Well, the lateralization
phenomenon is all over the human brain, as we've
seen. And there is evidence that there's
lateralization, for instance facial detection, in the
monkey. Work hasn't been done on the chimp, but
it's been done on the rhesus monkey. There's
evidence for brain lateralization. But it is not a
process that is believed to be widely present in
the animal kingdom.
Alan Alda: So you don't see it in terms of the
shape of the brain in other animals? And you don't
see it, or it hasn't been found, in the use of the
brain, in the way that the brain processes?
Michael Gazzaniga: There's been a suggestion
that the part of the brain that is specialized for
language is larger in the left hemisphere than in the
right. But that does not hold up to careful analysis.
We have to look more deeply into the nervous
system organization to figure out why a particular
brain structure does what it does. Those are deep
questions that we just don't have any answer to
right now.
Alan Alda: What about consciousness? How does
that fit into all of this? Is consciousness related to
the corpus callosum, or the division of the brain
into these two hemispheres in any way?
Michael Gazzaniga: The issue of consciousness
is the $64,000 question. And if you look at it in
terms of what we mean by it, which is sort of that
phenomenal awareness that you and I are having
right now, and every member of our species has
every day, we don't have anything to say about it.
There's nothing to be said about it in a scientific
sense. What you can talk about is how information
comes into your conscious awareness, sort of what
some of the philosophers have called "access
question." And you can talk about our
self-knowledge capacity and how we build that
up. I think the interpreter plays a big role in that.
But to go from those discussions into some sort of
riveting remark about how the brain enables
consciousness is a jump that the scientific
community isn't ready to make yet, to my mind.
Alan Alda: You've indicated that if you lose the
use of some part of your brain, that doesn't change
your consciousness much. You make up a reason
for why you're seeing what you're seeing.
Michael Gazzaniga: Aging doesn't change. Don't
you feel twelve? I feel twelve. And then you look
in the mirror and this person looks back at you,
and you say, "Who the hell's that?" Right?
Alan Alda: That's right. I'm not conscious of it
internally.
Michael Gazzaniga: Right. Yet if we went into
your brain and looked at the structures that have
changed and been modified through the aging
process, they're considerable. And yet our sense
of who we are hasn't changed an iota. So trying to
peg real neuroscience to that phenomenon is the
great unknown issue in neurobiology, and we're
not on top of it.
Alan Alda: If changes happen in my brain, and I'm
not conscious of those changes, it seems connected
to the idea that you can't place consciousness in
one location in the brain.
Michael Gazzaniga: I'm sure you can.
Alan Alda: I'm sure you can.
Michael Gazzaniga: I'm sure you can. There's got
to be a process that emerges out of the actions of
all these millions of instincts that we have in our
brain. To pinpoint it at a spot or at a place would
be ridiculous. You know the old line, the
professor showing the new student around at the
college and he says, "There's the math building.
There's the physics building. There's the English
building." And the student says, "Yes, but where's
the university?" And it's going to be that kind of
feel to the answer.
Alan Alda: Consciousness is the university of that
story.
Michael Gazzaniga: Exactly.
Alan Alda: And it's sort of produced by all these
other functions. It's like it's a feeling that we have.
Michael Gazzaniga: That's exactly right. That's
what I think. And I think that's an important point
to make. It is a feeling about these specialized
capacities we have. And that alerts the student to
the fact that what neuroscience and cognitive
neuroscience are good at doing is looking at what
intelligence is, what a perception is, what memory
might be. Looking at those specific subcomponents
of mental life. And we're making big advances on
those things. But to jump to the question of
consciousness is premature at this point, and I
think we're not ready for it.
Alan Alda: I have to say - and from talking to you
I think you feel this way, too - consciousness is a
terrific thing to have. It feels good to have
consciousness. When you lose consciousness and
when you sense you're going to lose
consciousness, it doesn't feel good. You get a little
nervous about that. But what do you suppose is the
reason we have consciousness? Why has it
persisted? What good is it in terms of the survival
of the species?
Michael Gazzaniga: That's related to the $64,000
question. What's it for? If you want to understand
anything, you've got to know what it's for. And it
so permeates every thought we have, you think,
well, it's for keeping us motivated, to have these
thoughts, or whatever. But you start to put this stuff
down on paper and it just doesn't look like you're
saying much.
You know, there's a bunch of philosophers now
who are saying, "A human trying to understand
consciousness is like a nematode trying to
understand a dog." It's just too big a problem, and
they kind of toss it out the window. Well I don't
think we should do that. Clearly, it's going to take
a lot of major new thinking to really give us an
insight, a handle on how we can scientifically talk
about this phenomenal awareness that we all
experience.
Alan Alda: As we talk, it occurs to me, I wonder
if consciousness is similar to the taste of food.
Food tastes good, so we eat. And thinking feels
good, so we think. Maybe we wouldn't think as
much if it didn't feel so good to be conscious of
our thought.
Michael Gazzaniga: Yes, that's the feeling about,
kind of phenomenon. But you keep chasing that
back. Well what is that? What is the feeling about?
Who's appreciating that feeling? Where are you in
that diagram? And that's the hard nut to crack.
Alan Alda: Well if that's the feeling, if
consciousness is just a feeling that occurs when
you cogitate, then maybe the only reason for
consciousness is to make you cogitate a little bit
more. Otherwise you wouldn't bother with it. You
wouldn't bother eating if a hot dog didn't taste
pretty good.
Michael Gazzaniga: That's right. But there are all
those little mechanisms, obviously,
(servo-mechanisms, as a word) that allow you to
be motivated, to carry out those basic functions.
But when you try to nail it down to the
consciousness problem, I just don't see you get
anywhere.
Sure, if you're not appreciative of all the things
going on around you and you don't get a kick out of
working on problem solving and seeing your
grandchildren and your children or whatever, sure,
you're going to go motivationally flat and you
might kill yourself. But to say that doesn't help me
understand the scientific basis of consciousness.
Alan Alda: What's your guess about it? What
areas would you explore to try to get to the heart
of what consciousness is for?
Michael Gazzaniga: Well, the first thing is, it is
going to be a discovery of human neurobiology
studying humans. And this is an example of the
power, perhaps, of all the new brain imaging
techniques that are going to give us an
understanding we don't currently have of how the
brain is doing things. So measuring the human
brain and its responses to various psychological
paradigms ought to provide insight into that
question. But the exact experiment, if I knew it, I'd
be doing it right now. It's really tough.
Alan Alda: I think I read somewhere that you said
that it's what makes it all worthwhile. You were
talking about consciousness.
Michael Gazzaniga: Absolutely.
Alan Alda: Why for you does consciousness make
it all worthwhile?
Michael Gazzaniga: I don't know. I remember
when I was twelve years old. I just got interested
in those kinds of questions. And maybe it was
coming from a big Italian family or something like
that. "What the hell is going on around here?"
Whatever it was, I was drawn to those questions,
and over the evolution of the split brain work,
where we first made these observations 35 years
ago, we thought, "Well, we split consciousness
into two. Left consciousness, right consciousness."
That was part of our thinking for a number of
years, but then we saw that we did not really
capture the nature of these patients, that there were
far greater limitations in what the right hemisphere
could do, it wasn't an equal partner to the left.
Then we had different ideas about the content of
consciousness of each of those hemispheres. And
then that led to a set of other ideas that we've
discussed today.
But one is drawn to these things. I've taught too
many students to know there's some kids you
cannot infect with an interest in this topic. You
either have it or you don't.
Alan Alda: When you say that you think
consciousness is a feeling, what do you mean by
feeling? How would you define feeling in that
context?
Michael Gazzaniga: Yes, you see, you're really
after me here, and I can't get into my back-up brain
and answer you here. The point of that statement
was simply to remind people that there are many
facets to conscious behavior. And we're
understanding many of those facets. The
subcomponents of language and memory, retention,
perception. We're going after those, and those we
can deal with. Those we're making advances on.
But then this sentience question is wildly weird.
We're not just looking at that picture, we feel that
picture. We're not just talking, or listening to
language, we enjoy the poetry. That sort of feel to
things is the question that we don't have any insight
to.
Now many philosophers say, "Look, just go about
your business, solve all these component problems
in consciousness - the issue will fall out of that."
Alan Alda: Is there something you think about the
way our brains work that produces consciousness
and that's different from the way the smartest
machine can think?
Michael Gazzaniga Yes. Obviously, there are all
kinds of ways we solve problems that artifacts
seem not to be able to use at this point. Whether
they will be able to devise these methods is just
unknown. I would assume something close to it
will be built at some point. But the many ways in
which we solve a problem are sometimes hidden
to us. We just have the solutions sort of announced
to us, and then we try to give a rational framework
for how we came up with that notion. But the basic
mechanism by which we solved it is some circuit
in there that's responds to the variables and comes
up with an output that we can enjoy and benefit
from.
Alan Alda: And is that what we call intuition, do
you think?
Michael Gazzaniga: I think a lot of it is, yes. I
think what we call intuition is the response of the
built-in circuit. What the developmental
psychologists are teaching daily is the amount of
scripts that seem to be built into our brain. A
young child has these scripts, and when you
expose them to the right situation, boom, they are
elicited in full glory - and there's no evidence that
training or learning led up to the expression of
those devices.
All these things come on in stages. Why do they
come on in stages? Well, there's a maturational
process going on in the brain and that is enlivening
circuits that are built to handle specific cognitive
tasks. And as soon as they're operating, all of a
sudden the child can make that mental activity or
that cognitive activity.
Now those come off as intuition to some people.
Maybe intuition is just the inborn capacity to see a
relationship in the world, and to all of a sudden
have it announced to your consciousness. But it
was really built-in. It wasn't some wonderful thing
that occurred to you for which you should pat
yourself on the back. Your genome popped up
with the answer, and you happen to be in the body
it popped up in and generally congratulate yourself
over this great insight. We all do that, don't we?