From: Michael S. Lorrey (retroman@turbont.net)
Date: Tue May 09 2000 - 19:05:13 MDT
"Robert J. Bradbury" wrote:
>
> On Mon, 8 May 2000, Robin Hanson wrote:
>
> > >Full text:
> > >http://helix.nature.com/nsu/000323/000323-4.html
> >
> > This is disturbing; it suggests that ordinary brains get worse as
> > they get older. It's not that they stay fine and the body they
> > run gets worse.
> Its worse than that Robin. The recent work by Pakkenberg & Gundersen
> shows a neocortical neuron loss of 10% over the period from 20 to 90 yrs.
> That puts you at ~50% loss around 400 years. How much lower would you
> want to go???
> The older ref of Anderson and Hubbard, shows that it may be increasing
> to 1%/yr from 70 to 95. The methods used are different, and I'd trust
> the more recent work more. But it sounds like you are losing neurons
> at a rapid rate that is increasing with age.
> So, its either regrow neurons or freeze early if you don't want
> to be a shadow of your former self. Fortunately, recent work seems
> to show growth factors can stimulate neuron outgrowth and the rewiring
> experiments demonstrate a great deal of flexibility about taking on
> new functions.
> But it seems really undesirable to me to have to go back to college
> every 100-200 years to relearn everything you once knew.
> Side note some list members who like to express their positions
> "passionately" -- you won't remember any of this in a couple of
> hundred years unless you go look it up in the archives...
> Gives new meaning to "byegones".
Ah, but by then, we will have integrated the archives to ourselves as an
augmentation. I'll bet they don't even fill up a CD ROM yet. So long as
we keep it real and minimize on the HTML, I think we can make it another
ten years without going over one disk, unless of course our numbers
explode.
BTW: I'm reading Egan's Diaspora today so far so good, but not really as
engrossing as, say, a Broderick... How is it Damien, that he gets his
stuff published here and you don't? I haven't seen anything on the
shelves here since I bought The White Abacus. Borders didn't even have
you on their database.
Mike Lorrey
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