Brain complexity: learning new tasks (Introduction)

by dhw, Thursday, December 14, 2017, 11:10 (2537 days ago) @ David Turell

dhw: […] if, as you believe, consciousness is a separate entity, it cannot be the larger more complex brain that conceives of more complex concepts!
DAVID: Remember I conceive the brain as a computer. A larger more complex software in a more advanced computer allows more complex operations. […] My soul/consciousness operates the brain in life. […]

Your computer image has always been singularly unhelpful. Does your more advanced computer CONCEIVE of more complex software? Of course it doesn’t. So why do you maintain that “only the larger more complex brain [computer] can conceive of more complex concepts”? Now in your response you change this to: ”allows more complex operations”. In pre-sapiens the smaller brain had to expand in order to implement more complex concepts, but in sapiens the already enlarged brain did not “allow more complex operations", because having reached optimum size, it had to COMPLEXIFY in order to implement more complex concepts. It is the brain’s plasticity that ALLOWS more complex operations through expansion or complexification.

DAVID: What demands in a survival type life? Minimal compared to what our brain does now. I don't see the explosion pressures you are looking for.
dhw: You know perfectly well that I regard survival and IMPROVEMENT as the driving forces, and you have accepted improvement as a “major tenet” of evolution.
DAVID: Not changing. Read your own sentence taken from the last comment: " And yes, complexification could not cope with pre-sapiens’ demands, and so the brain had to expand." I repeat, what conceptual demands in a survival mode life require the expansion? My anwser, not one.

And I repeat, stop ignoring IMPROVEMENT. But since you insist, let me illustrate how the two driving forces can actually combine. Pre-sapiens man hungry. Him want eat (= SURVIVAL). Him want meat. Him fight animal and damned animal fight back. Him think: better way to kill animal (= IMPROVEMENT): me sharpen stone and attach it to stick and throw it at animal, then me no have to fight animal….Pre-sapiens man and his mates get together, and here I quote a dear friend of mine: “Once he learns to knapp flint, attach the stone point to a wooden rod, and then practices throwing it with accuracy, there is no question his brain has enlarged with all the muscle movement and visual coordination involved” (David Turell, 2 December, 15:07). An improved concept of survival has required and caused expansion.

dhw: Over the past 10,000 years the brain has COMPLEXIFIED, not enlarged (as pre-sapiens brains were able to do). In fact, as you keep telling us, it has shrunk. And so the optimum-sized sapiens brain was not hanging around waiting to be made full use of. It had to respond to new concepts by COMPLEXIFYING, as proven by modern science.
DAVID: The 200cc of highly complex hardware of the human pre-frontal cortex is what arrived 300,000 years ago. The fact that it could shrink a bit as new uses caused modifications of further complexity is simply an evidence of the computer power we received initially before complex use even began.

Agreed that the SIZE arrived 300,000 years ago. The fact that it shrank a bit is evidence that complexification was highly efficient. The brain must always have had a capacity for change/expansion/complexification (= plasticity), just like other cell communities, so how does that prove that your God kept expanding it before expansion was needed, leaving it hanging around waiting to be used?

DAVID: I believe it was highly complex to begin with, waiting for us to use it, but we had to learn to use it.
dhw: So instead of claiming it was the large brain hanging around waiting to be used, you now say it was the complex brain that was hanging around to be used. Of course it was highly complex to begin with, but now it is even more complex.
DAVID: […] The complexity you describe involves new connectivity, perhaps new neurons, but a degree of pruning to create the smaller size. This onboard plasticity ability attests to the initial complexity. In the past 10,000 years we have opened up its full ability for use.

Yes, plasticity is complex, and yes new connections and “perhaps new neurons” enhance the complexity, even if earlier ones are no longer needed and disappear (shrinkage). What is it, then, that was hanging around waiting to be used? Not the large brain, as that had finished expanding; not the new complexities, or they wouldn’t have been new. The only things that were hanging around waiting to be used were the potential for greater complexity of thought (the source of which, according to you, is the soul) and the potential for the implementation of the thoughts, i.e. NOT the larger brain, NOT the more complex brain, but the plasticity of the brain which enabled expansion and complexification in response to new thoughts. And both of these (possibly God-given) potentials were there from the start, since the same potentials must have been present in the first cells if you believe in common descent. (See also under “fine tuned…”)