Brain complexity: learning new tasks (Introduction)

by dhw, Saturday, December 09, 2017, 14:10 (2541 days ago) @ David Turell

dhw: You reminded me earlier of your dualistic belief that the brain is NOT the source of ideas, but clearly I am supposed to ignore the obvious contradiction when you say: “Only a larger more complex cortex can think of new more complex concepts.” You continue to ignore this contradiction.
DAVID: I maintain that only a larger more complex brain (pre-frontal cortex) can conceive of more complex concepts.

So you maintain that only the “soul” can conceive concepts, but only the brain can conceive more complex concepts. (On the subject of the 290,000 year "gap", see summary below.)

DAVID: I've never left out the idea that pre-sapiens brains had the same plexification/contraction ability we see now.

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. Our discussion centres on the major, permanent expansion of pre-sapiens brains. You maintain that all the learning and practising you described led to nothing but a minor expansion/ contraction, and your “then the brain complexified and shrank” only meant a return to normal size, which therefore has nothing to do with our subject of permanent pre-sapiens expansion.

In the light of all this, I will try to summarize your argument, and you can correct me if I’m wrong. The “soul” and not the brain produces concepts, but only a larger brain can produce more complex concepts. Implementation of the spear concept caused the brain to expand and then return to the same size as before. (Maybe even to shrink?) Then your God came along and expanded the brain and skull permanently. Only then could the brain think of more complex concepts, although it doesn’t think of concepts, and then once again it implemented them by minor expansions/contractions until God came along again and repeated the process. He finished expanding the brain approx. 300,000 years ago and left it to complexify (while momentarily expanding and contracting) but for some reason – not offered by you – it didn’t do very much for 290,000 years.

My argument: regardless of whether the brain is or is not the source of thought (which includes conceptualization), it has been proven that implementation of concepts requires changes to the brain. In pre-sapiens, although complexification may have coped with minor advances, major implementations would have required permanent expansion. This process of new concepts (or further development of existing concepts) being followed by implementation and consequent permanent expansion continued until the brain reached its optimum size (with sapiens), whereupon complexification took over from expansion and was so efficient that the brain shrank. Acceleration after comparatively slow progress for 290,000 years is explained through individual discoveries and innovations capable of rapid development by succeeding generations. Even if you disagree with this hypothesis, can you find fault with its reasoning, bearing in mind that it does not in any way preclude the existence of a God?