Introducing the brain: half a brain is just fine (Introduction)

by David Turell , Thursday, February 20, 2020, 21:04 (1736 days ago) @ dhw

DAVID: Totally illogical. Assuming an early hominin brain, how did it know what was newly needed so it could force expansion? The spear is invented only after the brain is already expanded and the new idea is developed from its new complexity and new ability to invent. Bass-ackward. The new sized brain dose not come with built-in concepts. They have to be originated with the new ability to think more deeply.

dhw: A truly astonishing explanation coming from someone who calls himself a dualist, which means ideas come from the “soul” not the brain. But in fact it makes no difference to my theory whether you are dualist or materialist. The whole point is that the idea precedes implementation of the idea, and we know from observation that it is IMPLEMENTATION of the idea that demands new uses of the brain – whether through enlargement or through complexification. The brain does not expand or complexify in anticipation of new ideas.

My view of dualism is not the standard definition in classical philosophy. I've explained this before. 1) Material, wet brain; 2) soul/consciousness makes ideas. Concepts developed by the s/c can only can be as complex as the complexity of the brain itself allows. Erectus saw flying birds, may have wised to do it, but never could figure out how.

dhw: You then asked how it worked:

dhw: My proposal is that the cell communities of which all organisms are composed followed precisely the same pattern we observe in the modern brain, and adjusted themselves to new requirements. And even today, complexification is accompanied by expansion in certain sections, according to the requirements of individuals.

DAVID: Same weird argument in the bold. A finished product in the modern brain is not an example of an earlier brain and how it formed. Enlarged area now developed from current requirements and are tiny compared to the enlargements of 200 cc's in past jumps in size.

dhw: Why weird? There is no reason to suppose that past brains functioned differently.

Yes, I agree previous brain functions and perhaps plasticity was an early form of what our brain does now. But nothing you have proposed tells us how the brain enlarged 200 cc per gap.

DAVID: The concept of plasticity, cannot be used as an overall theory of enlargement. Plasticity probably existed in all stages of brain size, but simply is a system of localized complexification/enlargement within a brain of a specific fixed size, as shown in our brain.

dhw: Exactly. But in the past, when the specific fixed size proved to be inadequate to perform the tasks required of it, the process of “localized enlargement”, as organized by the intelligent cell community using its own plasticity, would have led to overall enlargement. If it can expand on a small scale, why should it not have been able to expand on a large scale?

We have the example that refutes you. Our current brain with all its new uses and demands for even more new uses shrunk 140 cc from 30,000 years ago. It never had to enlarge! Except in tiny areas for very special use. So our brain is smaller and the erectus brain had to explode because it didn't have the ability to act like ours. But note above, we've agreed that earlier brains acted in most ways similarly to ours. But we can see our brain really has very special attributes.

DAVID: You should remember our brain has actually shrunk 140 cc in the past 30,000 years!!! While certain areas in some individuals (London taxi drivers) do enlarge with use.

dhw: Explained umpteen times: shrinkage would have been the result of efficient complexification. What is your explanation of shrinkage? God popped in again because he realized he didn’t need to give us so much brain? Yes, taxi drivers illustrate the same process which I propose applied at all times to all the different phases of brain development: the brain changes/changed through complexification, minor enlargement (within existing dimensions) or major enlargement (200 cc “jumps”) IN RESPONSE to new requirements, and not in anticipation of them.

Your 'new requirements' were what? When H. sapiens appeared 315,000 years ago what were the demanding new requirements that forced the brain to suddenly enlarge 200 cc? There are currently indigenous tribes now extant that live in roughly the same fashion as 315,000 years ago, with the same sized brain as the rest of us. They just haven't bothered to learn how to use it as we do, but they appear to have the same size, really unrequired. Point, same sized brain but haven't used it for new 'requirements'. Size and complexity first, use second. God supplies brain size as He evolves organisms.