Episode #359

[Crusafontia]

Hasn't this recently been found to be a myth, and that new brain cells do grow in later life? How memories are stored is obviously still largely a mystery, but I think it's pretty much accepted that it is a distributed process so that, for instance, knocking out one particular bunch of cells will not erase my memory of the cat I had as a child while leaving associated memories intact. I think some research also suggests that memories are is a sense rewritten (a bit like some sorts of computer memory) when they are accessed, to the extent that (say) traumatic memories can be partly erased by getting the subject to recall them and then causing a major distraction which prevents the memory from getting written back reliably. This suggests that, at least for memories we recall periodically, these could get copied into new nerve cells, leaving behind any dead cells which formerly formed part of the memory.

That's my amateur take on the subject. I'm sure Steve could put me right on a lot of things.

Steve could put me right too!

I was aware that recent research reveals that absolutely static brain non-growth in adults is not the case and there is some generation of new neurons in adults.  But from what I've read, that growth is apparently slow and it hasn't been established how extensively in limited regions of the brain that are resupplied .  Whatever the case, it is not a myth that we may lose brain cells (particularly catastrophic loss due to disease, injury or malnutrition) as we age and from that it would seem to be an advantage to have a large surplus to begin with for recovery from deficits.

[Fast Eddie B]

Steve did seem to imply that our brains may have pressure on them to increase in size due to increased need to process data.

I think that falls into an easy and obvious trap. Brains would only increase in size if there were a reproductive or survival benefit to that bigger brain.

But imagine a world where, on average, people of higher intelligence choose to have fewer offspring and people with lesser intelligence tend to have more. That should lead to decreasing intelligence over time, assuming there's a genetic factor to intelligence.

I think the movie "Idiocracy" explored that area. I think the group "Devo" took its name as a shortening of "De-Evolution", again exploring similar territory.

[quirk3k]

Brains would only increase in size if there were a reproductive or survival benefit to that bigger brain.

I don't think that is necessarily true. Variation can occur even within the same set of genes based on nurture. In this case, it's possible that by exposing infants to more information, they respond by developing a larger brain. This could occur without genetic changes.

This is a "just so" story with no basis, but it's an example of a way for average brain size to increase without selective pressure.

[Fast Eddie B]

Good points, all, and I agree.

I guess I just assumed we were talking about evolving larger brains, and that wasn't necessarily the case.

I did find this, however:

The name "Devo" comes "from their concept of 'de-evolution' - the idea that instead of continuing to evolve, mankind has actually begun to regress, as evidenced by the dysfunction and herd mentality of American society."

Of course, evolution has no "direction", but that's a whole 'nother thread!

[Crusafontia]

Steve did seem to imply that our brains may have pressure on them to increase in size due to increased need to process data.

And I'd have to admit that's the conventional wisdom more or less.

I think that falls into an easy and obvious trap. Brains would only increase in size if there were a reproductive or survival benefit to that bigger brain.

And the survival benefit is a longer lifespan takes full advantage of  preexisting evolved intelligence.  To give an extreme example, imagine if the longest humans lived was our mid twenties,  a human culture would then not have the benefit of individuals with life-long learning, experience and wisdom of seventy year-olds.   The best among us would be relatively green twenty somethings (with apologies to sensible well-educated twenty somethings).  This would be especially true for a culture without writing, and learning was on the job as opposed to the accelerated modern teaching methods through education and books.   

An alternative theory is that our souped-up human brain prematurely ages and neuronal redundancy merely compensates for that, and again, that has survival value.


 

[Ice Wolf]

WTN:

Right pericardial rub , not right - I thought it because it's coming up on 5 years after perry... Thought the lads might be trying to remember him.

I think it's a ventriculo septal defect murmur.

Might change my mind again.

Ice Wolf

[Henning]

Germany has many lovely, windswept and temperate beaches on the Baltic Sea!  :P
Just ask TalkingBook.

[Old Hoplite]

Germany has many lovely, windswept and temperate beaches on the Baltic Sea!  :P
Just ask TalkingBook.

Indeed it does. I have visited many. For a unattached het male the scenery is excellent!

[Old Hoplite]

There is also a practical limit to brain size, mainly having to do with blood (02) flow and the birth canal.
I read somewhere that human mothers died in childbirth about 20% of the time in nature just from humans have such huge noggins.

[GodSlayer]

There is also a practical limit to brain size, mainly having to do with blood (02) flow and the birth canal.

time to evolve into coneheads!

[Mr. Pedantic]

For WTN, my guess is aortic stenosis.

EDIT: after listening to it a few more times, maybe mitral regurgitation is more likely, if it's a heartbeat.

[seaotter]

Awesome show! The interview was fabulous.

[GodSlayer]

Awesome show! The interview was fabulous.

hopefully she'll do the reading if they make an audio book version of her book.  I just can't get over how similar she sounds to Dushku, the character, the articulation, everything. I'm so envious.

[Thorloar]

At the risk of pissing Steve or others off as this topic has been discussed before, but how are these Hasidic communities not considered cults? They seem to cut people off from the outside world. They use intimidation, withholding education and shunning to keep members in line. Could we agree that religions all fall somewhere on the cult spectrum?

[GodSlayer]

Could we agree that religions all fall somewhere on the cult spectrum?

if they do, then even our own families when we were growing up fitting "on the spectrum" ...at what point does it cease to be a useful word because the spectrum has made the category too broad?