Brain complexity: learning new tasks (Introduction)

by dhw, Tuesday, December 12, 2017, 09:14 (2539 days ago) @ David Turell

DAVID: I maintain that only a larger more complex brain (pre-frontal cortex) can conceive of more complex concepts.
dhw: So you maintain that only the “soul” can conceive concepts, but only the brain can conceive more complex concepts…
DAVID: The soul conceives new concepts by using a more complex brain cortex. For example, in teenagers they cannot fully evaluate dangerous situations and other considerations until the prefrontal areas are fully developed at age 26+/-.

As usual, the word “using” covers a multitude of activities, but it does not cover “conceiving concepts” if you insist that only the soul can conceive concepts. And I doubt if any of us can “fully evaluate” anything! The brain provides information, which it continues to do throughout life, and if the soul exists, it learns from experience (just like immune cells), and in turn uses the brain to implement its concepts. As the child's brain develops, it acquires and passes on more information and can implement more concepts provided by the soul, which is fed by the never-ending flow of information. But if only a more complex cortex can provide the evaluation, and hence all the concepts and decisions relating to the information (as in your first statement), you can hardly avoid the conclusion that thought stems from the brain. It may well do so. (Materialism versus dualism.)

dhw: There are two forms of contraction: one is the minor expansion/contraction (back to normal size) reported to take place in modern brains with each new implementation. This may also have taken place in pre-sapiens brains. The other is the modern brain’s major shrinkage by approx. 150 cc. - I suggest as a result of increasingly efficient complexification, which I would have thought highly unlikely in pre-sapiens, since the brain kept having to expand.
DAVID: I can accept this much of your theory. But our highly complex brain is not a pre-sapiens brain and with its high complexity may well have developed a method of much enhanced complexity to allow the shrinkage. Pre-sapiens present a different issue, lack of enhanced complexity, and therefore a different requirement for enlargement.

Why do you say “but”? You are repeating my own hypothesis in different words. Yes, our brain is different because instead of expanding, it complexifies. And yes, increased efficiency of complexification may have resulted in shrinkage. And yes, complexification could not cope with pre-sapiens’ demands, and so the brain had to expand.

dhw: In the light of all this, I will try to summarize your argument, and you can correct me if I’m wrong. (I shan’t repeat the summary here.)
DAVID: Your summary is close enough not to comment. The 290,000 years I have explained. Until 10,000 years ago humans and pre-humans lived in what I name as survival mode. If you have ever camped out you will understand. One needs clothing, shelter, a food source, and a small group of folks to live with resulting in some simple but necessary societal rules. With agriculture developing, we really began to civilized and use our brain much more fully. Why was it so big 300,000 years ago if we hardly had a need for it? Where were the driving concepts you propose? Here is where the teenager comment returns: it was available to be learned to be used.

An excellent summary of the history, and so I don’t understand why you find the process so mysterious. The brain reached its optimum size 300,000 years ago. For 290,000 years humans lived just as some of the remote tribes live now. Why not? Those tribes have managed perfectly well, and would no doubt go on doing so if we western know-alls didn’t keep interfering. But 10,000 or so years ago certain individuals came up with new ideas, and these were capable of rapid development. The optimum-sized brain was not waiting around to be used - it was INADEQUATE! And so the new uses demanded a new technique for coping: namely, enhanced complexification instead of the no longer possible expansion. The driving concept would have been the same mixture of survival and improvement (which you have acknowledged as a “major tenet”) that has driven all of evolution. Why did it take so long? All of a sudden 290,000 years is a long time. According to you it took your God about 3 million years to work our way from a lumbar change to full bipedalism. Homo erectus lived for at least a million years without making a great deal of progress. Why do you think your God left him hanging around all that time before doing the brain expansion trick? It might be more fitting to marvel at the speed with which sapiens developed his new concepts than to wonder why it took him 290,000 years to conceive them.