Brain complexity: learning new tasks (Introduction)

by dhw, Friday, December 01, 2017, 12:09 (2550 days ago) @ David Turell

dhw:... Do you think “indigenous” people have no language, culture, social life, tools, housing? Some even believe in gods.... You might say that they have not developed as much of the brain’s potential for complexity as you have. However, that doesn’t alter the fact that if the brain changes as a RESPONSE to new demands, its pre-sapiens expansions and current sapiens complexifications would not have taken place BEFORE the demands were made! And THAT is the issue we are discussing.
DAVID: That is exactly the point. You have introduced the nebulous concept of 'demands'. What demands could a people with smaller brains have if as I maintain they could not think of them as possibilities.

What you “maintain” is a major point of disagreement. I "maintain" that they can think of the possibility, and the effort to implement the concept causes the expansion. I offered the concrete, non-nebulous example of tool-making. According to you, God expanded the brain and then bigger-brained hominin thought of tool-making. But also according to you, conceptualization has nothing to do with the size of the brain, because it is the “soul” that conceptualizes, and according to modern science, the brain changes when it tries to IMPLEMENT the concept and not before. Put the two together, and you have small-brained hominin conceptualizing the tool, and the brain expanding as a result of his efforts to make the tool.

DAVID: The indigenous have made small demands on their giant brains because they haven't expanded their concepts of how to live as we do. They live little beyond the H. erectus life style.

Thank you for using the word “demands”, which you dismissed as nebulous a moment ago. You are quite right. When the brain reached its optimum size, and therefore complexified instead of expanding, different sapiens used it to pursue whatever way of life suited them. Some ways are far more complex than others. How does the fact that some sapiens make fewer demands than others prove that your God expanded the pre-sapiens brain before new demands were made on it?

dhw: And here you continue to focus on what may have happened before brains expanded permanently, whereas we are trying to find out why they expanded permanently. Your only answer is “God did it either directly or by pre-programming”, and you insist that he did so BEFORE hominins came up with their new concepts. And yet you agreed when I wrote that the cortex “remakes its connections and neurons in order to implement the demands made by the soul. It stays the same size until it can’t cope with the new demands, and then it adds more cells and expands accordingly.”

DAVID: I agreed: Of course it expands within its watery blanket, and then it contracts! The contraction is just as important as the expansion as part of the resident mechanism of the brain learning something new. You keep trying to ignore that to develop your expansion theory.
And:
DAVID: You agree with me that most probably pre-sapiens brains expanded and contracted. Then you keep trying to skip the contraction part in explaining why brains/skulls enlarged by 200cc. I will stick with God providing the change.

There are two different sorts of contractions. We know that sapiens’ brain has contracted in the sense of shrunk, but when implementing concepts it also does a mini-expansion and then contracts back to its normal size. Shrinkage has happened because complexification is so efficient that it doesn’t need as many cells as it once did. We know that pre-sapiens brain expanded permanently. We are discussing why. It may also have mini-expanded and contracted back again as it complexified, but even if it did, quite clearly the complexification was not efficient enough to cope with the demands being made on the brain by new concepts, and so it required more capacity. Why else would it have enlarged? According to you, your God expanded it, leaving all these additional cells hanging around with nothing to do until the soul came up with new concepts they could implement. This sequence runs contrary to what modern science (and common sense) has shown quite clearly: the brain changes (whether expanding or complexifying or mini-expanding and contracting) when it tries to implement new concepts, and not beforehand. You keep trying to ignore this proven process, which is not invalidated by a possible mini-expansion/contraction process within pre-sapiens brains prior to their permanent enlargements.