Brain complexity: learning new tasks (Introduction)

by dhw, Friday, December 08, 2017, 13:36 (2329 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: You do not seem to understand my theory, A small brain is limited in the concepts it can develop. Pre-habilis could not understand the concept of spear. It took a habilis-sized brain to have the concept and implement it, both occurring in the same brain, not a subsequent larger addition.

dhw: I do not understand a theory that contradicts itself. Let’s forget pre-habilis, since you begin with habilis: “If habilis has an idea for spears, the idea is immaterial. No brain change.” So small-brained habilis has the idea. “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 that the brain has enlarged with all the muscle movement and visual coordination involved.” It is therefore the implementation that enlarges the brain, and so from then on we have a post-habilis with a larger brain. (You went on: “But then the brain complexified and shrank” – skipping to Homo sapiens and the Indian readers, when the brain had stopped enlarging.) According to you and to me, the concept comes first, the implementation then enlarges the brain until we reach sapiens, when it can expand no further. You have described the process perfectly.(My bold)

DAVID: This is a total misinterpretation of what I have presented. It leave out brain contraction ability. What happened to your noting that my theory that brain enlargement and contraction occurred in all previous pre-sapiens might be correct.

It might be correct, but even if it is, clearly it could not contract enough to cope with certain new concepts, and that is when it had to expand permanently, just as you have described.

DAVID: All enlargement from implementation was followed by complexity reorganization and thus contraction, occurring in the same size skull at each stage of evolution. Thus on the way from Lucy (400cc) there were rough jumps of 200cc in each stage. And in each stage new concepts could be developed by the larger brain and implemented meaning even further slight enlargement within the same sized skull. You leave out the contraction part!

Contraction remains a “might be correct”, but it is you who quite rightly left it out of your description because it is irrelevant to the permanent expansion (the approx. 200 cc jump) which we are trying to explain and which you have described so perfectly. After that, once again there is a process of complexification (with possible contraction) within the same size skull until the next round of new concepts demands the next permanent expansion: new concepts first, without brain change, followed by implementation and enlargement.

dhw: Do you now wish to rescind all the above? If not, how do you square it with your insistence that your God had to enlarge the brain BEFORE the idea (which did not change the brain) and BEFORE the implementation (which enlarged the brain)? In other words, why must the brain be enlarged before it enlarges itself?

DAVID: I don't have to rescind what I did not present. You have attemped to imply that when I discussed expansion that forced a 200cc expansion.

What else could it have been? You specified that once the implementation process was complete, the brain had enlarged. And that makes perfect sense!

DAVID: I have never presented that view. I will maintain that artifacts prove the full abilities of the size of the brain being considered. And that size brain must be present to produce the artifacts , but first also develop the concepts from which the artifacts come.

Yes, the artefacts appeared when the brain had reached its next size, precisely as you have described. Please reread what you wrote (reproduced above). It makes no sense to claim that the idea, which did NOT change the brain, did not precede the enlargement, which took place through the process of implementing the concept by knapping flint, learning to throw etc., with “all the muscle movement and visual coordination involved”! Once more: concept with no brain change (to smaller brain) – implementation enlarges brain, and artefacts are then present – newly enlarged brain carries on complexifying happily for a while (possible expansions and contractions within same size skull) until tough new concepts arrive with no brain change – implementation enlarges brain again… – until we reach Homo sapiens, when enlargement ends and complexification takes over. This is exactly what you described, and I can find no fault in the reasoning.