Brain complexity: memory formation (Introduction)

by David Turell , Wednesday, August 28, 2019, 14:10 (1704 days ago) @ dhw

dhw: Although I can’t follow all the scientific stuff on this particularly thread, I’m very interested in the “hint at how brain cells change structure when they learn something”. This is a known fact (we had various examples earlier of the illiterate women learning to read, and of taxi drivers’ and musicians’ brains undergoing such changes). The obvious implication is that the brain does not change before the arrival of new activities but in response to them. Thus one can well imagine that the first pre-humans to leave the trees (for whatever reason) and the first pre-whales to enter the water would not only have adapted their bodies to the new environment but would also have undergone brain change as a result of these new conditions and the need to adjust their behaviour. In the case of pre-humans, so great was the number of new things to be learned that the existing capacity would not have been large enough to cope – hence expansion of the brain: not the result of random mutations or of divine dabbling, but of the brain cell communities responding to new requirements. Just a hypothesis, of course.

DAVID: Of course current brain cells have a great deal of plasticity, but that capacity had to have been designed into the current brain by some process. For me only a designing mind fits.

dhw: I don’t have a problem with that argument. My point was that if learning changes the structure of the brain, clearly the learning precedes the changes, which is why I suggest that the whole history of brain structure, including expansion, just like that of other organs, has come about through the cells’ responses to new situations, conditions etc. This proposal is in contrast to Darwin’s random mutations and to your own theory that your God made all the changes (either by preprogramming or by dabbling) before the new situations etc. arose.

The changes we know in Indian illiterates and London cabbies alters an existing brain but does not create a species with a new brain size and capacity. I think your theory is a real stretch.