Big brain evolution: brain size and intelligence (Evolution)

by dhw, Friday, April 20, 2018, 11:58 (2407 days ago) @ David Turell

DAVID: You are making black white from the facts we have. The only brain we can study is ours. The Cro-Magnon brain from 20,000 years ago was 150 cc larger in the frontal area where thinking takes place. Since then we have complexly civilized with massive concepts and implementations. All of the planning takes place in the front and it shrank from a developing complexity of neuronal connections.

You agree that the dualist’s “soul” does the thinking and the brain does the information gathering and the implementing, and you agree that shrinkage is the result of complexification. And so all you are saying is that the “soul” is situated in the brain (which is where thinking and planning take place). That doesn’t change its function!

dhw: So you now agree with my hypothesis concerning shrinkage, and you have agreed that the same processes we know today (thought causing brain change) would have applied to pre-sapiens and can therefore explain pre-sapiens’ brain expansion. What are we arguing about?

DAVID: Again black is white. The only process that we know about in brain function is shrinkage when operating under intense thought for concepts or planning for implementation.

We know that the brain complexifies and also expands in certain areas AS A RESULT of implementation (illiterate women, musicians, taxi drivers). Why do you persist in limiting brain activity to shrinkage, which is not associated with any particular concept but which you and I agree has been caused by the general efficiency of complexification?

DAVID: The brain cannot plan for implementation without thought. As for a pre-sapiens making a clay pot, it requires frontal lobe concepts and coordination with the visual area, the motor area, and the cerebellum. What has enlarged since Lucy is primarily the frontal lobes. Designing an airplane is all frontal lobe. Implementation is planning a factory in the frontal lobes! The factory workers use all parts of their brains in working at the factory. So, please define your use of the word 'implementation' as it relates to brain function. For the argument about brain size, it is important to know where thought and actions take place. The s/s/c is compartmentalized in its interface with the brain, a concept you struggle with.

Planning is thought, and once again you are talking of WHERE thought and actions take place, but that does not mean the brain does the thinking/planning! As usual, you are dodging the issue of your own dualism. All you are saying is that the thinking "soul" operates within different areas of the implementing brain. You know perfectly well what is meant by implementation, since you gave a model description of it yourself in relation to making the spear. Pre-sapiens “soul” (I am explaining dualism, not taking sides in the dualism v materialism debate) has the concept of a weapon that will kill from a distance. In order to make the weapon, his “soul” must get his brain to direct his body to make the shaft, sharpen the stone, attach the stone to the shaft, and throw the weapon with the required force and accuracy. This, as you point out, involves different parts of the brain. (The “soul” may even adjust its plans as it learns from the material results of implementation. That is all part of the interaction.) As with the examples we know through modern science, these new actions will require changes to the brain. In sapiens the direct changes are not shrinkage but complexification and in some cases limited expansion. Since you propose that the same processes would have taken place earlier in evolution, and since you agree that the “soul” does the thinking and the brain does the implementing, it is logical to propose that the implementing caused expansion in pre-sapiens. It is not logical to propose that the brain had to be expanded BEFORE the new concept could be conceived by the “soul”, since brain changes are known to take place as a RESULT of implementing new concepts, not before the concepts come into existence.