I agree my post was pretty vague. I've mentioned Rosenfield previously in one list or another, always hoping that *someone* who knows much more than I know about neurology (and about the many different theories as to the resemblance or non-resemblance of computing to brain activity) would pop up. Twice recently I have sat down to type in more information on his work (and on the neuorlogists he cites), but each time the server at ISU went down. I'll try to do so in the next day or two.
I'll quote as much from the last 4 pages of his book ("Epilogue and Conclusion") as I can before I have some tasks to do.
A spy sitting in a music hall might want tolocate the womanb he has just heard say, "Nine o'clock tomorrow," and he may also want to enjoy the singer's "Casta Diva." One set of brain maps will locate the person who side "nine o'clock," while another set of maps will permit him to hear the "Casta Diva" for his own pleasure. The sounds have been categorized in different ways by his brain in accordance with his adaptive needs: business and pleasure.
Later that evening the spy may realize he has forgotten the face of the woman he was shadowing during the concert. Annoyed, he hums the melody of "Casta Diva" and he is quite surprised to realize that in his imagination it is being sung by the woman he was following. This suggests that memor is not an exact repetition of an image in on'es brain, but a recategorization. Recategorizations occur when the connections between the neuronal groups in different maps are temporarily strengthened. Recategorization of objects or events depends on mot ion as well as sensation, and it is a skill acquired in the course of experience. We recollect information in different contexts; this requires the acxtivation of different maps interacting in ways that differ from those of our initial encounter with the information and that lead to its recategorization. We do not simply store images or bits but become jmore richly endowed with the *capacity to categorize* in connected ways.
Memory as recategorization is one of the deep implications of Edelman's theory of neuronal group selection. In a rmarkable book published in 1932 and entitled *Remembering*, the English psychologist Frederic C. Bartlett sketeched out the view which Edelman's work has give a precision and a physiological justification:
<quote> Remembering is not the re-excitation of innumerable fixed, lifeless and fragmentary traces. It is an imag8inative reconstruction, or construction, built out of the relation of our attitude towards a whole mass of orgaznized past reactions or experience, and to a little outstanding detail which commonly appears in image or in language form. It is thus hardly ever really exact, even in the most rudimentary cases of rote recapitulation, and it is not at all important that it should be so. <end quote>
It is this quality of memory that Freud, too, sought to capture. Believing that memories must leave permanent traces, and unable to see how a perceptual structure could remain open to new perceptions if it were altered by previous stimuli, he constgructed a thoery quite different from the view fo brain structure presented here.
Unable to accept that fragmentary memories may well be fragmentary, Freud assumed memories were fixed. In dispensing with fixed memories and replacing them with memory as recategorization, Edelman's theory represents a radical departure from previous thought, and may well open the way for a broader and deeper view of human psychology.
Each person, according to his theory, is unique: his or her perceptions are to some degree creations, and his or her memories are part of an ongoing process of imagination. A mental life cannot be reduced to molecules. Human intelligence is not just knowing more, but reworking, recategorizing, and thus generalizing information in new and surprising ways. I could be that inappropriate categorizations from damaged maps cause psychoses, just as the inability to correlate the succession of objects or events in time may be largely responisble for the loss of specific memories in some cases of amnesia.
In its present form, Edelman's theory is concerned with the formation of perceptual categories. The question of higher mental functions -- ultimately, language and consciousness -- is not considered, though, as Edelman has claimed, the theory could be extended to encompass them. The formation of perceptual categories, his theory claims, cannot be reduced to a few simple physiological mechanisms, or rules. Rather, the complexity and variabiltiy of the procedures needed for categorization are suggested by the multiple abstract mappings based on the selectional described in the theory. The simulations, such as Darwin II, that Edelman and his colleagues have developed demonstrate that these selectional principles can form the basis fo perceptual categorization. It remains to be shown how explicitly these simulations correspond to the workings of the brain.
If, however, it is possible to form categories with a relatively limited number of rules or, in a borader sense, if various mental functions could be performed by the brain in accordance with a few simple rules, then we would have good reason to question Edelman's theory. A reinterpretation of the clinical evidence, as argued in part 1 of this book, suggests, on the contrary, that higher mental function cannot be accounted for by relatively fixed procedures. Indeed, Edelman's theory confronts the very issues, categorization and generalization, that appear to be fundamenal to any understanding of higher mental funciton. It gives an intuitive sense, at the very least, of what the biological basis of mental life might be. The evolutionary princples at the heart of the theory are those on which the extraordinary advances of modern biology have been built.
Thus, while Edelman's theory is not directly concerned with higher mental function, it is not difficult to imagine how it might be expanded to help us understand the neurophysiological basis of language. Of course, language is acquired in society, but our ability to use it, to reconceive the world around us constantly, is, at least in part, a reflection of the multiple mappings and remappings that appear to be central to brain function. Such a view reinforces the idea that no two brains can be, or ever will be, alike. Edelman's theory of neuronal group selection challenges those who claim that science view individual human beings and other animals as reproducible machines, and that science is little concerned with the unique attributes of individuals and the sources of that uniqueness. Humanism never had a better defense.
DONE
Please note "neural darwinism" has to do with the second by second operation of the human brain *now*: it is totally unrelated to "psychological Darwinism," that last refuge of the scoundrels who call themselves psychological darwinists.