Conversations in Science with Dan Rather and Eric Kandel: Neuroplasticity

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00:00:44.07 RATHER: What's the difference between the brain and the mind?
00:00:46.29 Or is there any difference?
00:00:48.22 KANDEL: The mind is a series of processes
00:00:52.09 carried out by the brain.
00:00:54.16 So, the brain is responsible
00:00:57.02 for every mental process that you carry out,
00:00:59.17 from simple reflex acts, like hitting a backhand in tennis,
00:01:02.21 to the most creative acts of television journalism.
00:01:05.29 And one of the great contributions of 19th-century brain science
00:01:11.22 is to show that different functions, different mental functions,
00:01:14.29 are localized to different regions or combinations of regions
00:01:19.02 in the brain.
00:01:22.14 Broca, in 1860,
00:01:25.07 first showed that a lesion on the left side,
00:01:28.17 in the front of the brain,
00:01:30.22 is responsible for articulation of language.
00:01:33.23 If you have a deficit there,
00:01:35.18 you understand language perfectly well,
00:01:37.15 but you can't express it.
00:01:39.16 A lesion on the same side,
00:01:41.18 in the back of the brain,
00:01:43.15 Wernicke showed,
00:01:45.11 is responsible for you understanding language.
00:01:47.14 You could articulate it, but you don't understand it.
00:01:49.10 So, that first made us realize
00:01:52.11 that a complex function like language
00:01:55.11 has specific localizations in the brain.
00:01:59.14 RATHER: And help me with a definition: neuroplasticity.
00:02:02.17 What's the definition of neuroplasticity?
00:02:04.18 KANDEL: Neuroplasticity is the ability of the brain
00:02:07.08 to change its behavior as a result of experience.
00:02:10.23 If we carry on a conversation
00:02:13.25 or we have a pleasant afternoon together,
00:02:16.17 and you and I remember that
00:02:19.17 tomorrow or a week from now,
00:02:21.13 it's because our brain has been modified
00:02:23.28 as a result of that experience.
00:02:26.09 RATHER: How does the brain change and grow?
00:02:29.20 KANDEL: When one learns something,
00:02:32.23 signals are sent into the brain
00:02:34.24 that activate modulatory pathways
00:02:40.03 that cause the connections between nerve cells to change in function.
00:02:45.03 If you remember something very briefly,
00:02:47.24 like a telephone number
00:02:49.27 -- you remember it for five or ten minutes --
00:02:51.25 it's a functional change
00:02:54.06 that regresses back to its previous state.
00:02:56.18 If something is very important for you,
00:02:58.14 like meeting Dan Rathers
00:03:00.17 or having an opportunity to do something interesting,
00:03:03.04 you remember it for longer periods of time.
00:03:06.03 Or if you repeat something,
00:03:08.03 that actually gives rise to anatomical changes.
00:03:10.12 So that means that every single person
00:03:13.03 has a slightly different brain than every other person.
00:03:17.19 Identical twins with identical genes
00:03:20.25 have somewhat different brains,
00:03:23.09 because they will have different life experiences.
00:03:25.13 And one of the interesting things about how you grow those connections
00:03:29.22 is that the signals that are sent to nerve cells
00:03:34.20 to grow new connections
00:03:36.28 alter the expressions of genes in the brain.
00:03:39.29 People are astonished to hear that,
00:03:42.05 because they think that genes
00:03:44.25 are the controllers of the environment.
00:03:46.21 They think we are what we are because of our genes.
00:03:49.19 But they don't realize that the genes
00:03:53.12 are also the servants of experience.
00:03:57.12 When people interact to give rise to long-term memory,
00:04:00.16 they do this by altering gene expression.
00:04:03.01 And it's the expression of genes that is responsible
00:04:05.14 for the growth of new connections.
00:04:07.24 RATHER: Do you or do you not find people still surprised
00:04:10.19 by the plastic quality of the ever-changing brain?
00:04:16.02 KANDEL: Well, I think it's one of the great insights
00:04:18.05 of the last 30 or 40 years.
00:04:20.06 Let me give you an example.
00:04:22.15 There are some kids that are born
00:04:25.10 with a large cyst in the left hemisphere -- terrible.
00:04:29.05 That interferes with the areas involved in language:
00:04:34.03 Broca's and Wernicke's.
00:04:36.09 If you interfere with those areas in the adult person,
00:04:38.22 it's very bad news.
00:04:41.04 But in young children,
00:04:43.18 you can take out the whole left hemisphere
00:04:46.27 -- this has been done at Hopkins.
00:04:48.28 The right hemisphere takes over
00:04:51.08 and develops the capability for speech.
00:04:52.29 This is almost, I'm tempted to say, miraculous.
00:04:54.28 Miraculous in terms of our understanding 50 years ago.
00:04:57.29 So, I'm giving you the most remarkable example
00:05:02.11 of plasticity we know, removing a whole hemisphere,
00:05:05.14 including all the functions in it,
00:05:07.19 the god-given functions, so to speak,
00:05:09.26 and you find it in the other hemisphere.
00:05:12.19 RATHER: Now, let's talk about your past.
00:05:14.18 KANDEL: My past.
00:05:16.05 RATHER: And begin with the distant past.
00:05:18.12 You've written about your childhood
00:05:20.27 and about the Nazi concentration camps
00:05:23.11 during the occupation of Austria.
00:05:25.12 And you were a boy during this period. KANDEL: Yes.
00:05:27.23 Did the memory of those unquestionably traumatic events...
00:05:31.13 is that what got you into study of the mind and the brain.
00:05:35.19 KANDEL: Absolutely. It's had a profound influence on me.
00:05:38.26 I laugh because I think the in...
00:05:40.26 the influence is so interesting, and in some ways funny.
00:05:43.22 So, there are two aspects of it.
00:05:46.20 One is science,
00:05:48.16 and the other is my obsession about Vienna.
00:05:51.02 So, I left Vienna in 1939,
00:05:54.20 because we were gonna get killed if we stayed there.
00:05:58.12 And I came to Brooklyn. I went to Erasmus Hall High School.
00:06:04.01 And at Erasmus, I got interested in history.
00:06:07.01 I wanted to understand how people
00:06:09.26 who could read Goethe and Schiller,
00:06:12.00 who could listen to Haydn, Mozart, and Beethoven one day
00:06:15.03 go out and beat up Jews the next day.
00:06:16.18 It was incomprehensible to me
00:06:18.24 that I would meet a classmate
00:06:21.09 the day after Hitler came into Vienna,
00:06:22.23 and he would say to me, "Kandel,
00:06:24.25 my father said I'm never to talk to you again."
00:06:28.27 Unbelievable. And I tried to come to grips with that.
00:06:31.18 So, I began to study German and Austrian history.
00:06:34.28 I went to Harvard.
00:06:36.18 I majored in history and literature.
00:06:38.17 And I wrote my thesis on the attitude toward national socialism
00:06:41.08 of three German writers,
00:06:43.07 to understand, how could intellectuals get involved with Hitler?
00:06:46.12 While there, I got interested,
00:06:48.17 through a woman that I met,
00:06:52.00 in psychoanalysis.
00:06:53.23 And her parents were major analysts in New York.
00:06:55.28 And they said to me,
00:06:58.00 "History is not the way to understand the human mind.
00:07:00.03 It's through psychoanalysis."
00:07:01.25 So, I began to read Freud, and I was fascinated by Freud.
00:07:05.04 RATHER: I... I even read some Freud in the 1950s...
00:07:07.28 not a lot, mind you.
00:07:09.16 KANDEL: It was... it was an exciting new direction.
00:07:11.11 And he writes so well.
00:07:13.01 So I thought, you know, I would go to medical school
00:07:15.20 with the idea of becoming an analyst.
00:07:17.17 And I went to medical school with one idea.
00:07:19.26 And then, in my senior year,
00:07:22.12 there was a six-month elective period,
00:07:24.27 and we could do whatever we wanted.
00:07:26.13 And I thought, even a psychoanalyst
00:07:28.05 should know something about the brain.
00:07:30.06 So, I took an elective, actually here at Columbia,
00:07:32.28 and I got hooked.
00:07:35.01 And at the time, in 1956,
00:07:37.05 when I graduated from medical school,
00:07:39.12 physicians were being drafted.
00:07:41.09 And those who were qualified could go to the NIH.
00:07:44.11 I was selected by the NIH,
00:07:46.13 and I spent three magnificent years there.
00:07:48.16 And I learned how to do science.
00:07:50.20 RATHER: But you didn't start out to be a doctor,
00:07:53.01 a medical doctor?
00:07:54.13 KANDEL: I not only didn't start out to be a doctor.
00:07:56.12 I knew nothing about science.
00:07:57.26 I had no interest in science. I was int...
00:07:58.21 RATHER: And you didn't take pre-med at Harvard?
00:08:00.12 KANDEL: I took the three required courses.
00:08:02.29 I took them because they were prerequisites,
00:08:04.21 not because I liked any of them.
00:08:06.12 I didn't like them.
00:08:08.09 I got interested in science
00:08:10.06 because I decided an analyst
00:08:12.19 should know something about the brain.
00:08:13.27 And I started to do it.
00:08:15.13 Not only that, but we learn about science by reading books
00:08:18.02 or doing rote experiments.
00:08:20.01 Then, working in a lab is a completely different experience.
00:08:23.26 It's like a Talmudic experience.
00:08:25.23 You're debating -- should we do this? should we do that?
00:08:28.10 You know, is this a good idea?
00:08:30.08 It's so much more intellectual.
00:08:32.08 It's so much... it's a way of taking small degrees of creativity
00:08:36.04 and amplifying them.
00:08:38.17 So, I found it just magical.
00:08:40.27 And I continue to find it magical.
00:08:43.02 Look, I'm not a young guy,
00:08:44.22 but I work every single day doing science.
00:08:47.01 And it's just addictive.
00:08:49.00 RATHER: Talk to me about how the brain makes memories.
00:08:52.04 KANDEL: Memory is not a unitary function of the mind.
00:08:55.03 There are two major classes of memories.
00:08:57.25 Once is called explicit memory, or declarative memory.
00:09:01.28 It's what you conventionally think of as memory.
00:09:04.16 Recalling people, places, and objects. Okay?
00:09:10.00 The other is called implicit memory,
00:09:12.17 and that is a memory for perceptual and motor skills.
00:09:15.04 Riding a bicycle, hitting a tennis ball.
00:09:17.09 When you drive and you shift,
00:09:19.11 you don't pay attention.
00:09:20.28 You don't tell yourself, I have to move the gear shift this way.
00:09:22.22 You do it automatically after you've learned it.
00:09:24.13 RATHER: True.
00:09:26.11 KANDEL: Implicit memory, the reflexive memory, is unconscious.
00:09:29.08 You have to pay attention when you learn it, but once you do it...
00:09:31.21 boom, it's automatic.
00:09:34.24 Explicit memory
00:09:36.29 -- recalling your first television program, your first love experience, your first child --
00:09:40.09 it's a conscious recall.
00:09:42.10 So, they're fundamentally different.
00:09:43.24 They involve different areas of the brain.
00:09:46.12 The critical structure in explicit memory storage,
00:09:48.29 in memory of people, places, and objects,
00:09:51.09 is a region called the hippocampus.
00:09:54.11 And this was first discovered by Brenda Milner,
00:09:56.21 who's a spectacular psychologist,
00:09:59.11 now in her 80s, at McGill.
00:10:03.01 And she studied this patient, H.M.,
00:10:05.03 a very famous patient.
00:10:07.10 Somebody on a bicycle knocked H.M. over,
00:10:09.21 gave him a bilateral concussion,
00:10:12.08 and he developed seizures in both sides.
00:10:15.16 After a while, they became intractable.
00:10:18.01 So, when he was 20, he was operated on.
00:10:20.13 And the surgeon, Dr. Scoville,
00:10:23.03 removed the temporal lobes on both sides,
00:10:26.11 and he went deeper to remove the hippocampus on both sides.
00:10:29.19 And he left H.M. with a devastating memory loss.
00:10:33.13 H.M. could now no longer take in
00:10:37.05 any more new memories
00:10:40.06 and form them as long-term memories.
00:10:42.03 So, the ability to form long-term memory
00:10:44.18 absolutely requires the hippocampus,
00:10:46.13 and it came out of Scoville's surgery.
00:10:49.07 And H.M. had such difficulty
00:10:52.09 that when Brenda Milner would come to visit him
00:10:54.29 -- and she did this on a monthly basis for about 20 years --
00:10:57.10 every time she walked into the room,
00:10:59.12 it was as if he never saw her before.
00:11:01.22 Now, he could do implicit things perfectly well.
00:11:04.00 He could comb his hair, he could shave, he could do all this stuff.
00:11:06.07 But anything that rev... involved conscious recall...
00:11:09.08 reading the newspaper, he'd read one paragraph and forget the whole thing,
00:11:12.07 and he'd start all over again.
00:11:13.21 This was just a remarkable distinction
00:11:15.18 between these two kinds of memory processes.
00:11:20.24 RATHER: Some of the most highly trained Western physicians
00:11:24.03 are interested in using our ability
00:11:27.27 to actually map the brain
00:11:30.27 and apply that to meditation.
00:11:33.10 What are the chances we're overstating the potential of that?
00:11:37.22 KANDEL: I think zero.
00:11:39.29 I mean, meditation is an interesting mind state.
00:11:43.25 The brain is in a particular functional state,
00:11:46.14 which gives you certain calm,
00:11:49.24 certain focus of attention,
00:11:51.23 allows you to control your body in certain ways.
00:11:54.03 It would be wonderful to understand that.
00:11:56.02 You know, these are the challenges young people should be taking on.
00:11:58.19 You don't want to take a problem that's beaten into the ground.
00:12:01.05 You want to take a problem that's opening up.
00:12:03.16 And I think this is a fantastic problem.
00:12:05.10 To define situations for hypnosis.
00:12:08.07 One might be able to do certain kinds of dental procedures with hypnosis.
00:12:11.12 I'm only... you know,
00:12:13.20 this is not an area I'm specialized in.
00:12:15.13 But understanding special mental states
00:12:17.19 is extremely important.
00:12:19.28 We know so little about the major mental illnesses.
00:12:22.12 Depression or schizophrenia...
00:12:24.24 we just have the vaguest idea of...
00:12:27.23 perhaps this region is involved or that region is?
00:12:30.03 We need to understand the anatomical basis
00:12:33.09 for major mental illness
00:12:36.14 in order to make any progress in treating it more effectively.
00:12:39.13 And this is a major, major problem.
00:12:41.18 There's been no improvement in the treatment of schizophrenia
00:12:45.02 since the 1960s.
00:12:46.29 The new drugs have fewer side effects
00:12:50.04 than chlorpromazine, which was available to us then,
00:12:53.00 but they are no more effective by and large,
00:12:56.03 with some minor exceptions.
00:12:58.16 Selective serotonin uptake inhibitors like Prozac
00:13:02.01 have been around since, you know, 1980.
00:13:05.12 No improvement has occurred.
00:13:09.05 So, we are stuck here.
00:13:18.07 RATHER: I want to get back to these Buddhist monks
00:13:21.20 who have practiced meditation for decades on end.
00:13:25.12 But they are not scientists.
00:13:27.08 They are not people of medicine.
00:13:30.00 How much is there to be learned from their experience with meditation
00:13:34.02 that can be applied to real science?
00:13:37.13 KANDEL: I think an enormous amount.
00:13:39.10 Let me step back and put this in a larger perspective.
00:13:42.28 When neurobiology began to be more powerful than it was before,
00:13:46.06 people thought these neurobiologists
00:13:49.07 are gonna come along and they're gonna wipe out psychology.
00:13:51.24 I mean, everything we know up to this point
00:13:54.14 is folk psychology.
00:13:56.05 It's what your mother taught you.
00:13:57.20 And it's probably malarkey.
00:13:59.00 They're gonna come along,
00:13:59.23 and we're gonna have a completely new understanding.
00:14:01.23 Well, that's nonsense.
00:14:04.02 You know, what we have learned from Freud...
00:14:06.29 I mean, some of it is wrong, a lot of it is right.
00:14:08.29 What we've learned from various people
00:14:10.26 -- from Skinner, from Thorndike, from Pavlov --
00:14:12.20 these are profound insights that we've gotten.
00:14:15.00 The function of science
00:14:16.29 is to get a new level of understanding,
00:14:18.22 and to develop a new science,
00:14:20.11 a merger of psychology with neurobiology.
00:14:23.18 In fact, modern neuroscience is this synthesis.
00:14:27.00 So, if meditation is a new insight into the mind,
00:14:30.07 we want to understand it. Why not?
00:14:33.27 You know, artists and thinkers about behavior
00:14:39.12 often get very profound insights
00:14:41.18 into what's important to people and what people respond to.
00:14:45.23 Even religion... I mean, religion fascinates me.
00:14:48.18 I'm not a religious person,
00:14:50.24 but it's clear that this must be in some way instinctive, inborn.
00:14:56.21 I mean, wherever you go throughout the world,
00:14:58.11 people create religions for themselves,
00:15:00.00 just like they create art.
00:15:01.21 So, to understand,
00:15:03.09 what is the evolutionary drive?
00:15:05.01 Is it the concern about mortality?
00:15:07.09 That we're ultimately gonna die?
00:15:09.16 Or that there's mystery in the world,
00:15:11.12 and we're uncomfortable with it unstructured?
00:15:13.01 We have to develop some kind of a mythology about it.
00:15:15.07 But what is it in the brain
00:15:17.27 that requires that we have arts?
00:15:20.00 We don't need it.
00:15:21.28 I mean, it's not essential for survival.
00:15:23.10 It doesn't... it's not food, it's not protection.
00:15:26.07 But it enriches our life.
00:15:28.10 Religion enriches people's lives.
00:15:29.22 So, to understand that,
00:15:31.16 even though it comes completely from non-scientific sources,
00:15:33.23 is terrific.
00:15:35.06 Now, some are silly.
00:15:36.26 I think mental telepathy is nonsense.
00:15:38.14 You know, I don't communicate with a guy in New Jersey
00:15:41.08 by thinking thoughts.
00:15:42.29 But that's a personal opinion.
00:15:44.23 There are a few characters out there who believe in mental telepathy.
00:15:47.29 I think one has to use one's judgments about the fact that
00:15:50.00 there are some folk ideas that are just plain nonsense.
00:15:55.04 But many things... I mean, I've seen people meditate,
00:15:58.05 and I've seen how they can strengthen their stomach
00:16:01.03 and, boy, you can kick 'em in the belly
00:16:02.24 and they don't feel it.
00:16:04.04 That's amazing.
00:16:05.21 They... you and I can't handle a blow like that.
00:16:07.14 To understand what is it about the brain
00:16:09.28 that allows them to fend off an insult like that
00:16:12.21 is remarkable.
00:16:14.01 I want to understand.
00:16:15.26 You must be doing it through your brain.
00:16:17.26 You know, pain is a brain perception,
00:16:20.10 just like touch and sight.
00:16:22.22 So, if you become insensitive to pain,
00:16:25.12 something in the pain pathway is shut off.
00:16:28.04 Wouldn't it be wonderful to know how that works?
00:16:30.11 You know, people have pain from all sorts of causes.
00:16:33.08 To know how to modify that...
00:16:35.01 in fact, I would say that, of the problems in medicine,
00:16:37.16 one of the most bothersome ones
00:16:40.08 are various chronic pain syndromes.
00:16:43.24 We have very few good approaches to chronic pain.
00:16:46.10 We can treat acute pain.
00:16:48.19 Go to dentist, he gives you an injection... boom.
00:16:50.22 Or you take an analgesic.
00:16:52.02 But chronic pain is very difficult.
00:16:53.27 If we had other ways of doing this,
00:16:55.15 it would be terrific.
00:16:58.09 RATHER: Do you or do you not consider the brain the...
00:17:01.10 the last frontier science?
00:17:03.22 KANDEL: It is without doubt the last frontier of science.
00:17:05.20 To understand how you work,
00:17:08.22 to understand how the inner parts of your psyche operate...
00:17:11.07 it's fantastic.
00:17:13.06 This makes us who we are.
00:17:15.17 You want to know what it's like in Mars?
00:17:17.22 Who do you think that curiosity comes from?
00:17:19.18 It comes from your squash.
00:17:21.01 It comes from your brain.
00:17:22.17 All the questions we ask of the world come from the brain.
00:17:24.23 RATHER: Do you call it the squash sometimes? Is that what doctors call it?
00:17:27.14 KANDEL: The brain is a better term.

This Talk

Speaker: Eric Kandel

Audience:

General Public
Educators of H. School / Intro Undergrad
Student
Educators of Adv. Undergrad / Grad
Researcher
Educators

Recorded: July 2008

Talk Overview

Eric Kandel won the Nobel Prize in Physiology or Medicine in 2000 for his work on the nervous system. Here, he discusses the mind, the brain, and his journey into a life of science.

This interview was filmed in 2008 for a series on the mind and the brain. This video is a collaboration between the Lasker Foundation and iBiology.

Speaker Bio

Eric Kandel

Eric Kandel, M.D., is the Fred Kavli Professor in the Department of Neuroscience at Columbia University, and a Senior Investigator of the Howard Hughes Medical Institute. He is also Director of the Kavli Institute for Brain Science and Co-Director of the Mortimer B. Zuckerman Mind Brain Behavior Institute. Dr. Kandel has been at Columbia University… Continue Reading