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

by David Turell @, Monday, February 19, 2018, 18:26 (297 days ago) @ dhw

dhw: > 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?

Simple: a newborn has a brain which is simple and must develop full complexity, which occurs on average finishing in the prefrontal cortex by age 25. This is medically accepted. Of course new complexity appears with new uses after that.


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.

dhw: 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.

I used risk taking as an example. The judgment about the consequences of any new action by an individual is impaired or limited until the development of the prefrontal cortex is complete.


dhw: 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.

Please accept that full brain development from birth takes to an average age 25.


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.

dhw: 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.

Sorry about your disbelief but this is current medical theory about the length of adolescent judgment ability in regard to understanding the consequences of their actions. I've mentioned this many times in the past. Note his attorney is using it.


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)

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

The s/s/c controls the brain's thinking, but the depth of thought is determined by the stage of physical development of the brain's complexity which is not under s/s/c control but starts at birth. A six-year old cannot think like you do. The area for analyzing risk and other consequences of one's actions has been identified as residing in the pre-frontal cortex, believe it or not, it is accepted fact. And it proves my point that the s/s/c must work through the areas of the organized brain available to it. It can't work if the area is not fully functional. It may try but judgments will be skewed.


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