Introducing the brain: general (Introduction)

by David Turell , Saturday, March 05, 2022, 16:31 (781 days ago) @ dhw

DAVID: You still don't understand the need for intense mental activity behind creating complex designs. You don't hand off your play writing to a substitute, as a perfect example.

dhw: On the contrary, my point is that intense mental activity produces the complex designs. Whereas you argue that the complex designs are created in anticipation of intense mental activity... As a playwright, like many other writers I know, I begin with an idea and allow it to develop of its own accord; I do not want to know in advance what is going to happen (otherwise I myself get bored with it),

Thank you! You have again shown us your personal approach to designing a play. This is why you design a god who doesn't care about an end point to avoid boredom. A very humanized form of a god.

Physics current dead end

QUOTE: "The distribution of neurons in my brain is fractal, with density increasing as a power of D^2.decimal, much like Natalie’s description of Area^.75 power. It turns out that this is the optimal density to maintain connectivity between brain cells.

DAVID: Please note the bold about the design of our brain's neurons. Chance won't do that, only design will. Please remember my description of the specialized pyramidal neurons in five tiers dhw never dares comment about. It makes us very special.

dhw: I presume the quote applies to all brains and not just ours. I agree that we are very special,... I suggest that our frontal lobe would have evolved from existing frontal lobes in response to new requirements, whatever these may have been. Here is a fascinating article which at first sight you will think confirms your beliefs, but which goes on to support my own proposals:

New Study Changes Our Understanding of Human ... - Haaretz.com
www.haaretz.com/archaeology/new-study-changes-everything-we-know-about-hum…

QUOTES: …these structural innovations in the cerebral regions, thought to allow for many of humans' unique behaviors and abilities were probably in place by 1.5 to 1.7 million years ago.

"As we drove our dinner extinct, we had to develop capabilities and technologies to hunt down smaller, fleeter animals. We may also have needed increasingly to communicate in order to strategize the hunt for fast food. Right now this is speculative, but the truth is, it adds up.

dhw: It certainly does, though you will stick to your dabble of a few hundred thousand years ago.

I prefer my view of the article to your biased take:

"the modern structure of the frontal cortex where we do our advanced-human things such as language hasn’t been with us since our evolution began after all.

"We know this because it turns out that the first members of the Homo line to leave Africa – the diminutive primitive specimens found at Dmanisi, Georgia, dating to 1.8 million years ago – had frontal lobe structures like great apes, not like humans,

"On the other hand, hominins younger than 1.5 million years in Africa, and Homo erectus in southeast Asia from that time, did have human-type frontal lobe structures.

***

"Long story short, without going into the minutiae of analyzing frontal lobe organization in endocasts of fossils, the team concluded that the Dmanisi crowd had ape-like structures where it counts, and all the Homo erectus from southeast Asia had a more modern-like structure.

"Ergo the advanced structure had to arise after the Dmanisi residents left Africa. However, these structural innovations in the cerebral regions, thought to allow for many of humans’ unique behaviors and abilities, were probably in place by 1.5 million to 1.7 million years ago, the authors say. (my bold)

***

"...if a brain cast indicates a chimp-like Broca’s cap, the assumption is that the brain is primitive: The “single-furrow condition” is interpreted as representing the ancestral condition, she writes.

"The Dmanisi specimens show the unique furrow, which is the primitive condition, Beaudet told Haaretz. The Homo erectus, based on the inference of the casts, had a modern organization of the lobe.

***

"Also, more “recent” human species such as Homo naledi also show the human-like configuration, the double furrow, of the Broca’s cap, she adds.

"She also notes that the Broca area is involved in tool-making, and that all this begs the question: What kind of selection pressure may have been responsible for the reorganization of the human frontal lobes? Good question."

Comment: the Dmanisi are very early small homos found in an Israel area cave, out of Africa. The article clearly shows giant sapiens brain advances long before any current needs and uses. Note the early appearance of "Broca's language area long before real language developed. All organized in advance for future use. Part 11 follows.