Response to criticism of Neural Darwinism
Response to criticism of Neural Darwinism
|31. 'Making an organism is a pretty horrendously complex thing'||270||01:40|
|32. Ed Lewis||250||00:37|
|33. The sciences of recognition and population thinking||394||01:44|
|34. An original thought at Zurich airport||1||537||02:52|
|35. The Neurosciences Research Program||429||03:53|
|36. Why I don't think the brain is a computer||838||03:51|
|37. The theory of neural Darwinism||972||05:14|
|38. The idea of re-entry||1||698||03:40|
|39. The idea of value||567||03:43|
|40. Response to criticism of Neural Darwinism||528||05:08|
Well, there's one thing I've left out and it's a very important thing philosophically speaking or morally speaking... I don't know how to put it. And that is the so-called idea of value. All of this occurs somatically in an individual according to this theory but it can't occur unless you've already inherited something that we call value. Let me illustrate that by a concept... how do I put it? By... by saying there are, there are anatomical structures in the brain, about six of them, called value systems. For instance if I go like this, your locus coeruleus which is a set of little blue spots about 6000 neurons each, release noradrenalin all over your brain through a leaky hose. If I have you tested and you're trying to perform something for a reward, you release dopamine through another set of signals coming from parts of the ventral tegmentum and also something called the basal ganglia. If I go to other parts of the brain, it's acetylcholine. There are these diffuse ascending systems that you are born with that have been selected by evolution to give you rewards or punishments if you will, according to your behavior. Those condition the selection I mentioned in this ternary relationship, developmental, experiential and re-entry. So you have this system working together and that was the gist of the theory I put together in Zurich.
Well, since then it's been elaborated much more completely and, indeed, in 1987 I published a book called Neural Darwinism. Well, that released a bit of a storm and I found out that, independent of its merits, if you want to have a lot of disturbance around you, theorize in biology. There's no doubt that it's a little bit different than in physics. In any case the book gave a much more extensive analysis of the situation from more points of view and of the developing theory, and it also of course looked for evidence to support the theory. Now, as you know, there's no way you can prove a theory in science; there's only a way you can perhaps disprove it. And so far I'm happy to report the theory hasn't been disproven. I personally believe it is terribly important to have that theory because, unlike the other organs that develop, as complex as they are; say the kidney or the liver, the brain is after all giving rise to these amazing properties of knowledge, consciousness, all of the philosophical notions etc., etc., epistemology, how you know, how it all goes together, language. So how does this all go together in this disparate mess? There are so many different levels of organization in that brain that you're struck through with awe when you really look at the complexity of it.
Well, the position I took on the theory was this: that maybe we can't prove it, because you can't do that with a scientific theory, but at least we can show it's self-consistent. And so, as a result of that, my colleagues and I have run a series of brain models. We've made models of these different processes that I talked about, and shown that at least the theory is self-consistent. If you try to express a theory like this just in words, the complexity is not embedded. You've got to go into details and see how that goes, and in a series of publications we did just that. Again you notice the word ‘we’ because in fact I've been fortunate to be joined by a number of people, particularly at this institute, who are interested in this issue.
US biologist Gerald Edelman (1929-2014) successfully constructed a precise model of an antibody, a protein used by the body to neutralise harmful bacteria or viruses and it was this work that won him the Nobel Prize in Physiology or Medicine in 1972 jointly with Rodney R Porter. He then turned his attention to neuroscience, focusing on neural Darwinism, an influential theory of brain function.
Title: The idea of value
Listeners: Ralph J. Greenspan
Dr. Greenspan has worked on the genetic and neurobiological basis of behavior in fruit flies (Drosophila melanogaster) almost since the inception of the field, studying with one of its founders, Jeffery Hall, at Brandeis University in Massachusetts, where he received his Ph.D. in biology in 1979. He subsequently taught and conducted research at Princeton University and New York University where he ran the W.M. Keck Laboratory of Molecular Neurobiology, relocating to San Diego in 1997 to become a Senior Fellow in Experimental Neurobiology at The Neurosciences Institute. Dr. Greenspan’s research accomplishments include studies of physiological and behavioral consequences of mutations in a neurotransmitter system affecting one of the brain's principal chemical signals, studies making highly localized genetic alterations in the nervous system to alter behavior, molecular identification of genes causing naturally occurring variation in behavior, and the demonstration that the fly has sleep-like and attention-like behavior similar to that of mammals. Dr. Greenspan has been awarded fellowships from the Helen Hay Whitney Foundation, the Searle Scholars Program, the McKnight Foundation, the Sloan Foundation and the Klingenstein Foundation. In addition to authoring research papers in journals such as "Science", "Nature", "Cell", "Neuron", and "Current Biology", he is also author of an article on the subject of genes and behavior for "Scientific American" and several books, including "Genetic Neurobiology" with Jeffrey Hall and William Harris, "Flexibility and Constraint in Behavioral Systems" with C.P. Kyriacou, and "Fly Pushing: The Theory and Practice of Drosophila Genetics", which has become a standard work in all fruit fly laboratories.
Tags: 1987, Neural Darwinism
Duration: 3 minutes, 43 seconds
Date story recorded: July 2005
Date story went live: 24 January 2008