X-Message-Number: 796
Date: Sun, 3 May 92 22:16:41 +0200
From:  (David Stodolsky)
Subject: CRYONICS: #768 - Re: Brain Scan Question

Brian Wowk <> said:
>        Aside from the technical difficulties, holography at best provides  
>only limited external views of an object.  Anatomical structures in such  


X-ray holography would, if it worked, allow examination of internal structure in
the storage media, just as internal structure can be recovered from a brain by
electron microscope. That is, you adjust the focal depth to see a certain
distance inside the specimen.

>to some 3 trillion rads!  Such a scan could only be performed on a frozen  
>brain (to prevent chemical diffusion), and would take about 100 years due to  
>heat dissipation constraints. 


Well, after a hundred years virtually reality technology ought to be good enough
to reprogram a new brain :-). Seriously, this delay would be irrelevant to the
patient, even if revitalization techniques were available earlier (a big if).

>        Finally, there is the fact that such a scan would not reveal anything
>about the chemcal state of synapses, which is probably just as critical to  
>memory as connectivity.  

Really? I thought the chemical state was dependent to some degree on what part
of the brain the cell was expressed in. Couldn't this info could be determined
by other means?

>Indeed, the lack of molecular information is the  
>greatest weakness of non-invasive tissue characterization techniques.  How  
Sufficient resolution would recover molecular information, but how small an
object needs to be resolved? With best current techniques, individual atoms can
be imaged. These are invasive, but my major point earlier was that tissue
destruction may be irrelevant with imaging. Some nanotech approaches are also
invasive. For instance, there has been discussion of the frozen brain being
pulverized, but the position of each fragment carefully recorded for later use.

>could we possibly recover personal identity from an x-ray scan when we  
>couldn't even recover the genome? 

One copy of the genome could be kept around separately, just in case :-).
This is easy to do right now, as compared to preserving whole organs.

 
>        I trust this question has been laid to rest. 

Not quite.

If we look at the problem as one of *Personality Reconstruction,* that is,
getting the original information back into a functioning brain, then there is a
good argument for using multiple information storage schemes. A brain image
would contain a lot of info. The genome contains a lot of info. Other
recordings, such as this message I am writing also contain info. 

Today, most of my intellectual work is captured in great detail on my personal
computer, this could certainly restore gaps in my memory (has already). What I
would like to see is a set of guidelines on how to capture the info. passing
through my personal computer in a way that would be most useful for personality
reconstruction. Capturing the info. passing through my personal computer in a
consistent and reliable way has turned out to be remarkably difficult.


>From the legal-ethical side, putting old memories in a new brain might have 
some
advantages over putting an old brain in a new body. Some years back, I wrote a
short paper concerning the ethical question of using a cloned body for
revitalization, but it was not easy to sell. (The clone must be sacrificed,
murdered in today's terms. This could cause legal problems.) On the other hand,
loading a clone with new memories does not involve a currently defined crime.

But those California bureaucrats are really going to have trouble with this one.
Philosophers, get working :-).

David S. Stodolsky                Messages: + 45 46 75 77 11 x 24 41
Department of Computer Science                 Tel: + 45 31 95 92 82
Bldg. 20.1, Roskilde University Center        Internet: 
Post Box 260, DK-4000 Roskilde, Denmark        Fax: + 45 46 75 42 01

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=796