Brain complexity: learning new tasks (Introduction)

by dhw, Thursday, November 16, 2017, 14:02 (2564 days ago) @ David Turell

DAVID’s comment: The cerebrospinal fluid around the brain allows for this temporary expansion. Learning to write with the opposite hand is more complex than learning how to make and throw a spear. This answers the question of expansion of hominin brains. They also had a fluid area around their smaller brains which had room to expand and contract without changing skull size. Time to abandon your unsupported theory about need driving a new permanent brain size.
dhw: It’s quite extraordinary how we can read the same article and come to diametrically opposed conclusions. First of all, you are the one who keeps emphasizing that hominin brains underwent several jumps in size with a corresponding expansion of the skull. My explanation: the brain expanded and required a bigger skull. It finally reached its optimum size, which seems to be confirmed by these experiments: the brain now expands initially and then returns to its “normal” size, by which time it has rewired itself. You had never mentioned this particular type of expansion before, but that simply provides further proof that the brain expands in response to need. So that must be what happened to the hominins and hominids, until the skull could expand no more.

DAVID: Did you miss or ignore the point that the brain can expand without enlarging the skull! And can shrink back as it accommodates the new complexity of connections, and as we saw in learning to read, it always shrinks back. We have no evidence for continuing expansion (in small steps), only 200cc gaps in the fossils.

The brain shrinks back NOW! You have explained above how it is able to expand slightly, but way back in hominin days, you keep telling us the skull expanded, so it must have expanded when the brain couldn’t shrink back enough to be contained within the existing skull.

dhw: Secondly, I don’t know why learning to use the opposite hand is “more complex” than learning to make and throw a spear, but in any case all the changes are CAUSED by unfamiliar activities, whether it’s spear-making and throwing, using the opposite hand, or learning to write (the Indian women). It’s crystal clear that the brain responds to needs (or desires), and changes itself accordingly. So it really is time to abandon your unsupported theory about your God expanding the brain BEFORE it could think of new concepts. Concepts activate and change the brain.
DAVID: Again, skipping the knowledge the brain always shrinks back.

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. 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. 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, but that your God realized then that it was going to expand too much so he popped in and gave our hominid friends 200 cc extra skull to accommodate the expanding brain? In other words, He did NOT give us a bigger brain, but only gave us a bigger skull? I’d have thought it would be simpler to have the different cell communities cooperating as the need arose, but at least this would harmonize with your dualism. (I’m still hoping to return to the compromise between dualism and materialism which may be the key to this issue.)