Brain complexity: learning new tasks (Introduction)

by David Turell , Sunday, December 03, 2017, 16:09 (2329 days ago) @ dhw

dhw: According to my hypothesis pre-sapiens brains most certainly had the mechanism for expansion, and eventually expanded by approx. 200 cc whenever the process of complexification could no longer cope with new demands. Whether, prior to that moment, they also contracted is irrelevant, but they may have done so. Our question is why the brain expanded permanently, and so if it did contract, the rate of contraction (through complexification) was eventually not sufficient to cope.

The smaller brain produces the concept. The process of implementing the concept, as you have described so vividly, is what enlarges the brain. The brain did not enlarge before the concept and its implementation, so why do you say your view is different from mine?

I'm not with you on the smaller brain producing an idea/concept and that somehow forces a larger brain to appear to implement the idea. A larger brain has the capacity to implement, but we always disagree on what causes the brain to enlarge. I'm with God.

DAVID: But then the brain complexified and shrank. Based on human athletic training their skulls stay the same size, as in the newly newly trained Italian readers. Small ezxpansion and contraction.

dhw:Now you are confining your observations to Homo sapiens. 300,000 years ago the brain/skull reached its optimum size, and so instead of reaching a point where it HAD to expand, it responded to new demands by complexifying (as with the Indian readers), and this process was so efficient that it actually shrank. The mini expansion and contraction takes place as the brain restructures itself, and this may well have also been the case in pre-sapiens until it required permanent expansion, after which the same process would have repeated itself until the next permanent expansion.

DAVID: You have thrown out one of the major tenets of the study of evolution. Improvements build on each other. Sapiens did not invent brain expansion/contraction. Don't you think Neanderthal brains worked the same as ours? Without question, it came from earlier homos' brains. Your first paragraph ignores the sequence of use of the brain: " But you have him doing it BEFORE new concepts made it necessary, whereas I have hominins doing it WHEN it was necessary." Concepts do not enlarge brains. Only functional use of new practices does.

dhw: When have I ever said improvements don’t build on each other? Of course they do. And I’m delighted to see you at last agreeing that improvement is one of the major driving forces behind evolution. In concrete terms: simple artefacts needed expansion 1. Better artefacts needed expansion 2. And when have I ever said sapiens invented the process? Complexification would have taken place in pre-sapiens’ brains just as it does in ours (maybe with mini expansions and contractions, as discussed in our last exchange), but when demands exceeded the capabilities of complexification, they expanded permanently.

Yes brains expanded by large amounts to allow new complexities of action and thought. You theory is that cell communities forced the action and I've said idea/concepts appear without any effect on brain size as they are immaterial. But I also maintain that increasingly complex thought requires an increasingly larger more complex brain. God provided them.

dhw: In us further expansion was not possible and so complexification took over. You have finished by triumphantly repeating and supporting my case against your theory! Brains were not enlarged BEFORE the concepts and the implementation of the concepts, as you have insisted until now. The small brain produced the concepts, and the implementation caused the enlargement.

I've supported nothing of your nebulous theory that cells get together and somehow enlarge brain/skull. Nor am I sure that further expansion is not possible, but I do believe we are at the end point. We do agree that larger brains allow more advanced implementations. We will always disagree on the cause of the immediate enlargements.