Brain evolution

[DarkerSky]

This subject might be pushing the envelope in terms of content type for a stargazing site, but

In my opinion, the lifespan of humankind is generally tied to the physiological / biological processes of our bodies. That is, we die as a result of our body failing as a consequence (more often than not) of some sort of organ failure. It makes me wonder as to the longevity of the human brain should the falability of the ‘body’ element be removed / resolved.

Could the human brain continue to store memories and evolve if it were hardwired to a mechanism or substrate that were to mimic the human body after it has died? For me it is a concept that has some legs (pardon the pun!)

[ollypenrice]

Doesn't the brain begin to deteriorate quite soon after reaching maturity? Mathematicians peak in their twenties. Your memory also gets rapidly worse - or mine has!

And isn't evolution something that happens between individual creatures, not to individual creatures?

Olly

[GazOC]

If the brain usually only starts to seriously deteriorate long after humans have passed on their genes to the next generation would there be much selective pressure to pass on genes from people with brains who have "better" brains in later life?

I know a lot of hereditary conditions are passed on because they only affect the carriers in later life after they've had children, maybe having brains that start to fail in middle/ old age is a similar situation?

[ollypenrice]

Fair point, Gaz. One exception which I think I read about concerned the slow and demanding growth of baby humans. There might be a selection pressure favouring the family with living grandparents, so adult humans considerably outlive their reproductive phase as a consequence, unlike many animals. As I approach sixty I like to think there might be something in this!

Olly

[brianb]

There might be a selection pressure favouring the family with living grandparents, so adult humans considerably outlive their reproductive phase as a consequence

In many societies it's common for female relatives (especially aunts & grandmothers but also older children) to assist in child care. This makes good evolutionary sense, in the absence of medical care many women die in childbirth, I think it was as high as 1 in 8 in "advanced Western democracies" as recently as 100 years ago. This is a much higher rate than most mammals; part of the evolutionary cost of that huge brain.

As for adult humans outliving their reproductive phase - this is a recent phenomenon, in "primitive" societies, if degenerative diseases didn't get you predators certainly would. Experience can only partly compensate for diminishing strength & stamina and slowing reactions. I'm approaching 60 too but it's necessary to be realistic about this ... I'm not as strong as I once was, I get tired easily and my driving has started to slow down to compensate for slowing reactions.

[DarkerSky]

I guess the alternate scenario would be to engineer an artificial brain into which our individual conciousness could be implanted. It would not be evolution as such - more brain / memory preservation - but presumably, if such an artificial brain were to exist and mimic a human brain, it could continue to learn.

Sci fi at the moment, but I do wonder how a brain would react under the realization that its body died. You'd have to undergo some quite intensive prep I would imagine to be able to cope!

[brianb]

I guess the alternate scenario would be to engineer an artificial brain into which our individual conciousness could be implanted.

Our conciousness is a model of the universe as seen by our senses, so if individual conciousness could be "cloned" this would result in the creation of a new individual with initially the same set of "experiences" - they would of course rapidly diverge after that.

I do wonder how a brain would react under the realization that its body died.

Presumably the same way that it reacts to general anaesthetic - the brain will "shut down" before "death" however you define "death". If your consciousness has been cloned to alternate hardware then the alternate personality will presumably react to your "death" in the same way as you react to the death of another person, probably a close relative.

There is extensive sci-fi literature on readout of personality after death; my favourite is "Ubik" by Philip K. [removed word].

[Budding Star Gazer]

robotics are pretty much on brink of creating AI very much like a human brain or wired in the same way, and i do remember reading an article a good few years back about microchiped brain storage capacity or something along those lines, so given a few free willing test subjects i think we have what it takes today to try ans download a human brain to a storage device.

and the brain does not die when the body does it has been proven that electrical activity can remain a good few months after death.

that siad for the sci-fi fans out there i would recommend house of suns by alastair reynolds, awesome read about clones.

[ollypenrice]

May I intervene to howl in protest at this adoption of the American 'alternate' in place of the tried and tested English 'alternative.' Alternate means 'every other time' and not 'a different option.'

Don't you just hate former English teachers??

Olly

[brianb]

May I intervene to howl in protest at this adoption of the American 'alternate' in place of the tried and tested English 'alternative.'

Sorry ... I'll try to remember in future.

Don't you just hate former English teachers??

No.

[brianb]

it has been proven that electrical activity can remain a good few months after death.

Reference please!

Once the whole brain stops coordinated electrical activity, it's dead, even if there is residual random firing of isolated neurons for a while after that. But I think you'be be talking hours or a day or two at the most even in that scenario ... after months, the only electrical activity remaining would be from the nerve networks in the nematode worms that are munching on whatever remains of the grey gloop.

[DarkerSky]

May I intervene to howl in protest at this adoption of the American 'alternate' in place of the tried and tested English 'alternative.' Alternate means 'every other time' and not 'a different option.'

Don't you just hate former English teachers??

Olly

I stand corrected

[DarkerSky]

Our conciousness is a model of the universe as seen by our senses, so if individual conciousness could be "cloned" this would result in the creation of a new individual with initially the same set of "experiences" - they would of course rapidly diverge after that.

Presumably the same way that it reacts to general anaesthetic - the brain will "shut down" before "death" however you define "death". If your consciousness has been cloned to alternate hardware then the alternate personality will presumably react to your "death" in the same way as you react to the death of another person, probably a close relative.

There is extensive sci-fi literature on readout of personality after death; my favourite is "Ubik" by Philip K. [removed word].

Interesting! The quest for brain immortality in this instance then it would seem may spawn a new personality. Time would tell I suppose if such a thing could be classed as evolution.

I'll have a look out for that book Brian - thanks.

[ollypenrice]

Sorry about my linguistic digression there. Nematode worms, sea squirts... the glories of nature are never far away in Brian's posts! Never read them over breakfast...

Olly

[Budding Star Gazer]

Reference please!

Once the whole brain stops coordinated electrical activity, it's dead, even if there is residual random firing of isolated neurons for a while after that. But I think you'be be talking hours or a day or two at the most even in that scenario ... after months, the only electrical activity remaining would be from the nerve networks in the nematode worms that are munching on whatever remains of the grey gloop.

you can be brain dead as in loss of all higher function so you dont have the ability to work your own heart lungs etc " brain dead or stem dead" both the same thing a doc would call it either way.

but electrical activity can remain during coma with no hope of ever coming back as long as you can maintain cerebal blood flow, they have kep people in this state for some time.

but yes you are right the longest period of electrical activity after brain death, that i could find was 168 hours

reference: Electroencephalographic activity after brain death. [Arch Neurol. 1987] - PubMed result

[michigander]

May I intervene to howl in protest at this adoption of the American 'alternate' in place of the tried and tested English 'alternative.' Alternate means 'every other time' and not 'a different option.'

Don't you just hate former English teachers??

Olly

Only those Americans who've forgotten what they learned in grammar school. It's not 'American'; it's just bad English.

Dana

[brianb]

bad English.

Badglish?