Brain complexity: learning new tasks (Introduction)

by dhw, Wednesday, December 13, 2017, 13:32 (2537 days ago) @ David Turell

I am editing this exchange in an effort to keep it more concise.

DAVID: I maintain that only a larger more complex brain (pre-frontal cortex) can conceive of more complex concepts. (dhw’s bold)
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.

dhw: ...the word “using”…does not cover “conceiving concepts” if you insist that only the soul can conceive concepts.[...] 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.
DAVID: This seems reasonable if you accept that consciousness/soul run the brain.

I do accept that consciousness runs the brain, no matter whether consciousness is a separate entity (dualism) or is itself engendered by the brain (materialism). But if, as you believe, consciousness is a separate entity, it cannot be the larger more complex brain that conceives of more complex concepts!

dhw: 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.
DAVID: What demands in a survival type life? Minimal compared to what our brain does now. I don't see the explosion pressures you are looking for.

And now you changing the subject! You know perfectly well that I regard survival and IMPROVEMENT as the driving forces, and you have accepted improvement as a “major tenet” of evolution.

Dhw: 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!

DAVID: Not inadequate, but enlarged with many more neurons and branching axons and synapses. Then it could easily the exploding knowledge and thought over the past 10,000 years.

Over the past 10,000 years the brain has COMPLEXIFIED, not enlarged (as pre-sapiens brains were able to do). In fact, as you keep telling us, it has shrunk. And so the optimum-sized sapiens brain was not hanging around waiting to be made full use of. It had to respond to new concepts by COMPLEXIFYING, as proven by modern science.

DAVID: I believe it was highly complex to begin with, waiting for us to use it, but we had to learn to use it.

So instead of claiming it was the large brain hanging around waiting to be used, you now say it was the complex brain that was hanging around to be used. Of course it was highly complex to begin with, but now it is even more complex. Or do you reject the findings of modern science, which tell us that the brain changes whenever it implements new concepts? Or do you believe that these changes leave the brain exactly as it was 300,000 years ago?

dhw: 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?
DAVID: I don't know why each jump in size took so long. Ask God. We have to accept what we see.

Then instead of asking why it took sapiens 290,000 years (no big deal in the grand scheme of evolution) to come up with his new “civilizing” concepts, why don’t you just accept what you see?