Sunday, December 16, 2007

"Rythms of the Brain": Part II

Way back in September I talked about "Rhythms of the Brain" by György Buzsáki, a book of great scope ostensibly about just three questions, according to the author on p. 5:
1. how are EEG patterns generated,
2. why are they oscillatory, and
3. what is their content?

I can assure you the book is about a great deal more than just some pat answers to these three questions, because to even begin to answer them, Buzsáki ranges far and wide, and brings back mountains of info to share.

As I looked the intro over again, I found this on page 17:
Hippocrates's view of the brain was that from it arose all "pleasures, joys, laughter and jests, as well as our sorrows, pains, griefs and tears." A century or so later, Aristotle asserted that the heart housed the soul and ran nervous functions, and the brain was "an organ of minor importance, perhaps necessary to cool the blood."

Buzsáki says, "Aristotle's linear causation managed to suppress the correct view for more than a millennium. His revisions were based on several deductive arguments" ... such as the heart is affected by emotion, all animals have one, it is warm, it is essential to life, it's in the middle of the body and well-protected, etc.

Buzsáki asks,
"How can we argue against overwhelming intuitive "evidence," such as the "logical" examples cited above? Surely facts are needed but facts are always interpreted in context... similar skepticism can be expressed within the framework of dynamic complex systems. What does it mean to conjecture that the brain is a pattern-forming, self-organized, non-equilibrium system governed by nonlinear dynamic laws, and how should we prove or disprove this?"
He goes on to say that many have tried, that it is not easy, and that it's important to distinguish between concepts and mechanisms. In an accompanying footnote he says,
"Concepts are substrate independent, whereas particular mechanisms always depend on some kind of substrate. Although concepts borrowed from other disciplines can assist in addressing a problem or gaining a new insight, understanding mechanisms always requires experiments on the relevant substrate (the brain, in our case). Concepts can be developed by introspection, but their validity can be confirmed or rejected only by confronting them with mechanisms. A general problem in neuroscience is that the same terms are often used interchangeably as concepts or mechanisms (e.g.., inhibition of memory as a concept and inhibition as a mechanism)."

This began to tie in with the thinking along I've been doing with Tree of Knowledge. In the next section titled "Scientific Vocabulary and the Direction of Logic", he talks about how language and meanings get squeezed, like living things almost, over into meanings not originally intended by the speaker. He asks,
"Are our top-down concepts, such as thinking, consciousness, motivation, emotions, and similar terms, "real," and therefore can they be mapped onto corresponding brain mechanisms with similar boundaries as in our language? Alternatively, do brain mechanisms generate relationships and qualities different from these terms, which could be described properly only with new words whose meanings have yet to be determined? Only the latter approach can address the issue of whether the existing concepts are just introspective inventions of philosophers and psychologists without any expected ties with brain mechanisms. I believe that the issue of discovery versus invention is important enough to merit illustration with a piece of neuroscience history."

More to come about this.

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