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

by dhw, Thursday, February 22, 2018, 13:09 (2255 days ago) @ David Turell

I am combining comments from various posts on the same subject. I’m afraid many of my own comments are repeated, since the same response applies to most of the objections that David raises.

DAVID: The prefrontal cortex develops a judgmental area about one's actions future results as part of the development from birth. Can it be altered later. Of course. But the initial development takes to an average age 25. to be complete enough to make mature decisions.

dhw: So it’s not complete, and once more according to you, despite your claim to be a dualist, it is the prefrontal cortex that makes decisions.

DAVID: No, it is the area where the s/s/c can use the brain to make decisions. s/s/c and brain must be able to interface fully in each developed/developing area.

Just to clarify, which is essential if we are to reach an understanding: the s/s/c takes the decisions and it uses whichever part of the brain it needs to express or implement the decisions. That is how they interface in dualism, as you keep agreeing. And so the development of the pre-frontal cortex does not become “complete enough to make mature decisions” (which is what you wrote above) because according to your dualism it doesn’t make decisions.

DAVID: As above, the brain must be developed enough in the prefrontal area to allow all the attributes described for the s/s/c to act.

Yes. In other words, the brain has to have the requisite means to express and implement the thoughts/feelings/decisions etc. of the s/s/c. The plastic brain is the requisite means, and each new experience establishes the new connections. See later.

dhw: In this context, I notice you have ignored my question: What does current medical theory tell us about the soul?
DAVID: Snarky.

Yes and no. You don’t seem to have realized that the medical research you keep referring to is based on materialism, not on dualism.

DAVID: The s/s/c can only work to the point that brain development has reached from childhood to age 25 in the prefrontal area.

The individual s/s/c comes up with or is confronted by new ideas, tasks, concepts, wishes, decisions etc. at all stages of life, not just up to age 25, and it “works” by expressing/implementing these new ideas etc., thereby developing new complexities in the brain. Clearly there will be more new ideas etc. in the earlier stages of life than later, and hence the development of more complexities, but the process is never completed. One example will suffice to illustrate both points: the illiterate women learned to read and write (new concept for them), and thus established new connections within the brain. The connections were not established before they learned to read and write, i.e. the s/s/c makes the decision and the brain implements it by complexifying. There is no reason to suppose that the same process would not apply to a 50-year-old as to a 15-year-old.

DAVID: If the prefrontal area is not complete, the s/s/c cannot make fully adult judgments, because it must liaise with a fully functioning prefrontal cortex to do that. This supports my theory that brain complexity comes before complex thought is developed.

The prefrontal area is never “complete” so long as it is capable of new complexities! Please explain what you mean by “fully adult judgements”. You accept that the s/s/c does the thinking and the brain does the expressing and implementing. Once the implementation/ expression has been mastered, then of course the complexity is there for subsequent use, but cometh the next new concept, cometh the next new complexification. Thought comes before the brain change that implements/expresses it.

DAVID’s comment: I present this to show the illustrations which present different areas of the brain in the study the s/s/c must interact with. The s/s/c uses the brain as a tool.

Precisely: the s/s/c uses the brain (or different parts of the brain, and not just your favourite pre-frontal cortex) as a tool to express or implement its thoughts/concepts. And if the brain has not met with a particular concept before, it adjusts in order to implement the concept. It does not make the adjustment beforehand. And it does not stop implementing new concepts at the age of 25.

TONY: So, we shouldn't allow people to be considered adults until 25?

I would take that two steps further: 1) we shouldn’t allow people to be considered responsible for their actions until 25? 2) If judgement depends on the “completion” of the pre-frontal cortex but, as Tony and I have pointed out, the pre-frontal cortex continues to complexify AFTER 25, then we shouldn’t allow people to be considered responsible for their actions at any age? Exit free will, exit responsibility, and adults who commit murder, rape etc. can blame their wretched pre-frontal cortex for their mature or immature judgement (apparently depending on age). Tony’s remaining posts highlight the general chaos of David’s materialistic dualism and the inadequacy of the tests with admirable clarity. (However, I hope eventually to continue my efforts to reconcile dualism and materialism!)