Brain complexity: learning new tasks (Introduction)

by dhw, Monday, December 04, 2017, 13:56 (10 days ago) @ David Turell

dhw: 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?
DAVID: 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.

On Saturday 2 December, you gave an exact description of the process (my bold):
DAVID: If habilis has an idea for spears, the idea is immaterial. No brain change. Once he learns to knapp flint, attach the stone point to a wooden rod, and then practices throwing it with accuracy, there is no question his brain has enlarged with all the muscle movement and visual coordination involved. But then the brain complexified and shrank.

The small-brained hominin - I don’t know which one started it all - has the idea. No brain change. He learns to implement the idea, and once he has performed all the actions you have described so vividly, “HIS BRAIN HAS ENLARGED”. Therefore his actions caused the enlargement. That is precisely my hypothesis. (“But then the brain complexified and shrank” describes the stage 300,000 years ago, when the brain presumably could not expand any further and complexification took over.) On Sunday 3 December, however, you claim the exact opposite: the smaller brain can’t have the idea, and the implementation does not cause the enlargement. I’ll stick with your post of 2 December. And you can still be with God, since he may have designed the mechanism enabling expansion. You finished by summarizing my hypothesis as if it were your own: “Concepts do not enlarge brains. Only functional use of new practices does.” Yes indeed. Concept conceived in small brain, and implementation enlarges brain. Therefore your God did not enlarge brain before concept and implementation.

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.
DAVID: 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.

So have I. The concepts are thought up by the smaller brain, and as you have described above, it is the implementation that causes the expansion.

DAVID: But I also maintain that increasingly complex thought requires an increasingly larger more complex brain. God provided them.

And I maintain the same: the new concept requires expansion, which takes place just as you have described above. Your God did not expand the brain and skull BEFORE the concept and its implementation, but he may have provided the mechanism that made implementation possible.

dhw: 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.
DAVID: 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.

There is nothing nebulous in the hypothesis. You have described every detail in the most concrete terms possible. Maybe there could be further expansion, but there can be no doubt that at least for now, complexification has taken over, and modern science proves that the brain changes when AND NOT BEFORE it implements new concepts: expansion for hominins, complexification for sapiens. On 2 December you were in complete agreement with me on the cause of the enlargements, so we do not “always” disagree.


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