Big brain evolution: changes in sapiens skull shape;addendum (Evolution)

by dhw, Monday, February 19, 2018, 14:16 (2467 days ago) @ David Turell

dhw: You repeatedly use the words “complete” and “full”. If the cortex remains capable of new connections at any age, what do you mean by “complete” (other than size)?
DAVID: I stated complexity. Please re-read my sentence above.

You wrote: "the human adult does not have a completed pre-frontal cortex until age 25." […] "What is not complete until age 25 is the complexity of the neuron network and the ability to use that network to its full capacity."

How can the complexity be “complete” if it continues to add new connections after the age of 25?

dhw: And what is a fully developed s/s/c?
DAVID: One that has the brain complexity to judge risk taking. Standard psychological theory requires full pre-frontal cortical development.

Why are you confining the activities of the self/soul to risk taking? And is judgement of risk the activity of the self/soul or of the brain, bearing in mind that according to your dualistic beliefs it is the self/soul and not the brain that does the THINKING.

dhw: I know teenagers whose judgements I would trust infinitely more than those of certain adults. They do not have to wait until their brains are “ready for him/her to think and make judgements at the adult level”. What is an adult level of judgement?
DAVID: See my statement above.

Since different adults may reach different judgements, all you seem to be saying is that you can’t be an adult until you are an adult.

dhw: Here is an important quote from the article:
QUOTE: “The importance of the need to understand the changes in the brain and its implications on the adolescents and the families may be understood from the fact that shaping the development of the brain is in the hands of the teenagers themselves. Positive experiences lead to an adaptive brain. The teenagers who go through adverse experiences in this age are bound to remain disturbed for the rest of their life, given that they are not supported by adults.“ (My bold)

DAVID: Of course the teenager contributes, but ignores the necessary pre-frontal development occurring until average age 25.

What does this mean? The article makes it clear that experience shapes the brain’s development. I don’t suppose any of us are aware that our experiences are changing our brains, regardless of age.

DAVID (in addendum re the appalling Florida shooting): What does this mean to our discussion? This kid could not reach a rational conclusion. By psychiatric theory his pre-frontal cortex was not physically developed enough to allow him to reach a proper analysis of the outcome of his plan, both as it applies to him and to his victims. His attorney has already brought this up in his defense. From the viewpoint of this discussion his s/s/c did not have the brain hardware to work with, since it was still underdeveloped. As I've said all along, the s/s/c must have sophisticated brain hardware to achieve advanced conceptualization. Complexity first, artifacts second, as shown by this episode.

So if anyone aged 25-100 commits an act of indiscriminate slaughter, it must be because their fully developed pre-frontal cortex enables them to make a proper adult judgement. And everyone under 25 is devoid of the ability to reach rational conclusions because their pre-frontal lobe is not physically developed enough etc. I don’t believe it. Please see your response to my final sentence below and apply it, say, to a 24-year-old.

dhw: In dualistic terms, then, experience determines the teenager’s s/s/c (though a percentage of the s/s/c is already formed at birth), which in turn determines the development of the brain. I would therefore argue that complexification is ongoing, both in the s/s/c and in the brain (even a 60-year-old illiterate will make new connections when learning to read and write). And except in cases of material outside interference such as disease, accident, drugs, alcohol (all evidence for materialism), it is the s/s/c that controls the brain and not the other way round.
DAVID: Yes the s/s/c controls the brain. (dhw's bold)

So why do you keep insisting that the pre-frontal cortex makes the judgements or “proper analyses”?