Brain complexity: learning new tasks (Introduction)

by David Turell , Wednesday, December 06, 2017, 18:32 (2325 days ago) @ dhw

DAVID: You seem to be accepting that the current human brain is an end point, which fits with my belief that it was/is God's purpose to produce.

dhw: If the human brain is an end point, so are the duckbilled platypus, the skull-shrinking shrew and the whale.

Very likely evolution is over is not an unlikely possibility.

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: According to you and to me, the concept comes first, the implementation then enlarges the brain until we reach sapiens. You have described the process perfectly.

The issue between us is how the enlargement is caused. I say God does it with each new species with a larger skull and brain.

DAVID: You accept that pre-sapiens brains might complexify with new implementations and then you withdraw the idea! And sapiens did have brain and skull shrinkage as part of the known history.

dhw: I have not withdrawn the idea! I don’t believe that EVERY new concept and implementation resulted in a new species of hominin! The pre-sapiens brain would have complexified in each form of hominin until complexification proved inadequate to implement new concepts, and then it expanded exactly as you have described above. Sapiens could not expand any more, and so complexification alone had to cope, and did it so efficiently that the brain has shrunk.

I think sapiens are the endpoint of evolution, so expansion is unlikely.

dhw: We remain in perfect agreement, except that you refuse to agree that we agree.

We do not agree as to the cause of skull/brain expansion. God does it.

DAVID: We have never agreed on my point that more complex concepts require a more complex larger brain to be developed and then implemented. Size first, use second. Artifacts fully support my idea. I find yours totally illogical.

dhw: Again you use “developed” ambiguously.

Not ambiguous at all. Only a more complex brain can develop more complex concepts. When one thinks about a new approach, that is development of an idea. I don't understand your problem with the word.

dhw:The smaller brain has the concept (as you have described), and the brain enlarges as it implements the concept (as you have described). Concept first, implementation second, new size results from use, which is part of implementation (as you have described). The concept may be still further “developed” in the new larger brain, but in due course, once complexification is inadequate, implementation of the further developed concept will again require further expansion.

Only a larger more complex cortex can think of new more complex concepts. Size must come first. I will not give on that point

dhw: Each new, further developed artefact can only appear when the brain has finished its latest stage of enlargement (as you have described). That is why you will only see the respective artefacts together with the fossils of the larger-brained hominin that implemented the concept. I’m sorry that you find your perfect description of the process “totally illogical”.

It's not illogical. The difference in our approaches is the cause of the enlargement. I'm with God.