Brain complexity: learning new tasks (Introduction)

by dhw, Friday, November 17, 2017, 14:56 (2563 days ago) @ David Turell

DAVID: We fully know that the brain can expand to accommodate new learned skills and then shrinks back as it consolidates its new neurons and wiring. All shown in studies I have presented. All in the same skull size!

But that is NOW. We are discussing how and why hominin/hominid brains and skulls expanded in the past.

DAVID: And note that H. sapiens appears to be 300,000 years old, and even though we have learned all sorts of skills and concepts in that time period, our skulls are now slightly
smaller! Your concept about the brain forcing the skull to enlarge is totally untenable.

This is a complete non sequitur. Once again: brains and skulls expanded pre-Homo sapiens, and that is the issue we are discussing.

DAVID: Again, skipping the knowledge the brain always shrinks back.
dhw: Again, it always shrinks back NOW! The skull has reached its optimum size, and so the brain complexifies instead of expanding. But according to you, the brain and skull DID expand in the good old days of the hominins and hominids.
DAVID: Not according to me re' brain and skull. I'm simply repeating the known history of hominin evolution. And how do you know the brain has reached its optimum size? Are you now agreeing with me that this size brain was a goal?

Are you saying that prior to H.S. the hominin/hominid brain expanded but the skull didn’t? As for optimum size, no, I don’t “know” what will happen in the next thousand million years, but it seems logical to me that eventually brain, skull and body must find a workable equilibrium. And I’m not saying this size brain was a goal. I’m saying that if brain and skull had continued to grow indefinitely, we would have been in trouble. In my hypothesis, the cell communities adapt in order to find the right solution to such problems.

dhw: Meanwhile, you keep “skipping” the fact that all the evidence, including this new discovery, makes it clear that the expansion or complexification of the brain is the RESULT of trying to do something new, and THAT is the issue here.
DAVID: That is my point. I've skipped nothing as you twist and turn trying to manufacture a theory of brain size growth out of nothing.

My hypothesis is not “out of nothing”. It is that the growth results from the effort to implement new concepts, just as muscles expand with exercise. I thought your point was that your God expanded hominin/hominid brains and skulls before brains came up with their new concepts, as below:

DAVID: He expanded both skull container and brain to allow the brain to create more conceptualization as I firmly believe the brain cell communities cannot tell the skull cell communities to get bigger so the brain can expand. Both must happen at once as the 200cc gaps in skull size shown in the fossil record.

Back you go to your nebulous “allow”. Once again you have the physical brain creating concepts (which is fine with me if you are a materialist), whereas you have spent years arguing that the brain is only a receiver and it is the “soul” that creates concepts. But whichever it is (and I believe a compromise is possible), the brain cells in my hypothesis do NOT tell the skull to expand SO THAT the brain can get bigger. The brain cells expand with the effort of implementing new concepts, and the skull cells respond by adapting to the new size brain. This would only have been necessary when the capacity was not great enough to contain the expanded brain cell community, and it follows precisely the same process as all forms of adaptation: the cell communities change their structure in order to cope with new demands. The structure does not change in anticipation of new demands.

dhw:So are you now agreeing at last that the brain expands and contracts today as a RESULT of new concepts, and did the same in the old days?
DAVID: I've always followed the facts presented. Small degrees of expansion and contraction are allowed by the cerebrospinal fluid layer around the brain, as I've explained before.

No problem. The problem arises when there are large degrees of expansion, as above, pre HS. From your evasive answer I presume you do now agree that the brain expands and contracts today as a RESULT of new concepts, and did the same in the old days.

DAVID: Do you want a whole legislative body of cell committees negotiating all the size changes? Much simpler with God in control, or haven't you noticed?

But even your God in control would have to ensure that the cell communities worked together. Much simpler if he gave them the ability to do so than if he had to preprogramme or personally engineer every single body change!