Brain complexity: learning new tasks (Introduction)

by dhw, Tuesday, November 21, 2017, 14:44 (2559 days ago) @ David Turell

dhw: At least you seem now to have accepted that the brain expands/rewires IN RESPONSE to new concepts and tasks, which does away with the whole idea that your God expanded it before hominins, hominids and homos came up with their new concepts.
DAVID: Once I found the studies, I've always understood that the brain expands to handle new activities and then contacts as the new networks are reorganized. And you have accepted the probability that this mechanism probably goes back to pre-homo times. Skull size thus is constant. (dhw’s bold)

dhw (later): [..] And so instead of your now discarded hypothesis that God expanded their brains and skulls in ANTICIPATION of new tasks, the brain RESPONDED to the need to fulfil new tasks by expanding, and the skull expanded to house the expanding brain. (David’s bold)
DAVID: Note the bold. I've discarded nothing. Stop putting your confused thinking into what I write. I have described an enlarge/shrink mechanism that would keep the skull the same size as the brain handles new learning.

Note my bold in the first quote above. We were talking about pre-sapiens, and as you go on to say below, the skull did NOT remain the same size. It only remains the same size NOW. We are trying to explain why it expanded THEN.

DAVID: […] Each successive group of pre-homos and homos had gaps of larger brain/skull size adding an average 200cc with each more advanced species. […] Also each larger brain is found with more advanced artifacts. It is an unavoidable conclusion that a larger brain allowed the development of more advanced artifacts. Timing cannot be inverted, as you do.

There is no inversion, but yes, "the larger brain allowed the development of more advanced artifacts" in the sense that it enabled the initial concept to be implemented. As you have acknowledged, the latest research proves that the brain changes to handle new activities, and so pre-sapiens brains must have expanded when rewiring couldn’t cope. First came the concept of more advanced artefacts, and then the brain expanded through effort to implement the concept - just as now the effort to switch from right to left hand, or to learn to write CAUSED the initial brief expansion followed by rewiring. And so of course each larger brain is found with more advanced artefacts. It was only by adding cells that the brain was able to implement the task it was confronted with. Once again: we know that the brain expands and rewires itself (you call it an “enlarge/shrink mechanism”) AFTER the task is set, so why do you think that your God would have reversed the process and expanded the pre-sapiens brains (and skulls) BEFORE the task was set?

dhw:[…] I don’t think it’s unreasonable to suppose that eventually the brain reached the point at which further expansion would have damaged the balance of the body. And so from then on the “exponential growth of ideas and concepts” results in (not is caused by) increased rewiring, i.e. initial mini-expansion (mirroring the evolutionary process that led to the present one) followed by a return to the “normal” size as the brain implements the new task by new complexification. Shrinkage simply indicates the efficacy of the rewiring process.
DAVID: This is a non-answer to my paragraph above about the 300,000 year old sapiens brain size. Our large pre-frontal and frontal lobes allowed all the development of civilized knowledge I offered as evidence, very little of which existed 10,000 years ago. The new brain had an advanced ability for thought and subsequent shrinkage, an advanced evolutionary gift from prior homos under God's guidance.

Welcome to materialism. You keep telling us that the brain is NOT the source of thought, but now the brain has an advanced ability for thought. It may indeed be the source of thought, but whether it is or not does not alter the proven sequence of concept preceding changes to the brain. The large pre-frontal and frontal lobes mark the optimal size (you agree later: “it seems as if this current brain has reached an ideal level of development”). All our concepts from then on are implemented by rewiring/complexification.

dhw Expansion beyond current size would have proved impractical for the body. No more expansion now (beyond the mini-scale which soon shrinks back), but only complexification. All in a perfectly logical sequence.
DAVID: This sounds almost like me, but isn't. Ancient brains could only think of what they were shown to produce, no more.

Once again: Ancient brains expanded when the ancient homos thought of things their brains could no longer instruct their bodies to produce and use without expanding. Concept first, brain changes second, as proved by modern science.

DAVID: Note the bold. Where did that idea come from? We carry our skull on a smaller body than Neanderthals' burly bodies. Fossil skulls are in general proportional to their frames. The sci-fi literature of future humans with huge globular skulls is a ridiculous extrapolation.

As I indicated in my sentence which you have bolded. Indefinite expansion is "ridiculous". And so the time came when the brain could not expand any more without unbalancing the body, and the complex new thoughts had to be implemented by complexification (apparently preceded by a short-lived mini-expansion, echoing the process back in the old pre-sapiens days).