Received: by alpheratz.cpm.aca.mmu.ac.uk id XAA05697 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Tue, 25 Jul 2000 23:41:04 +0100 Message-Id: <4.3.1.0.20000725165641.00c30c70@pop3.htcomp.net> X-Sender: mmills@pop3.htcomp.net X-Mailer: QUALCOMM Windows Eudora Version 4.3.1 Date: Tue, 25 Jul 2000 18:38:40 -0400 To: memetics@mmu.ac.uk From: "Mark M. Mills" <mmills@htcomp.net> Subject: RE: Simple neural models In-Reply-To: <A4400389479FD3118C9400508B0FF230040E66@DELTA> Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
Derek,
At 11:06 AM 7/25/00 +0200, you wrote:
>Derek:
>Yes, I can follow that. Either neurotransmitter is released or it isn't.
>Fair enough.
>
>Mark:
>there is an inherent
>memory storage system involved. Knowing the 'charge state' at one moment,
>implies knowing the previous state. Voila!, memetic memory.
>
>Derek:
>Here you lose me. Why does the binary state of a nerve cell imply any
>inherent memory, or memory of any kind?
I'm not suggesting an entire nerve cell takes on a single binary state,
only that binary elements at the synapse level play key roles in
electro-chemical signal processing. Specifically, I'm alluding to
Kock's description of autophosphorylating kinases (Biophysics of
Computation). He suggested they are analogous to transistors. With a
certain amount of voltage applied to them, they conduct. Without the
voltage, they resist.
As to memory, if an autophosphorylating kinases is conducting, then its
previous state was non-conducting. They can only be one or the other. One
might say that the cells doesn't know 'when' the previous state existed (1
msec ago? 10 seconds ago?), but there is still a piece of inferential data
available about the past which a signal processing system could use. Add a
stable electrical wave pattern to the system and much more can be made of
the inference.
Since listening to neural signals crossing synapse membranes is very
difficult, most work on the role phosphorylating kinases comes from
observations of physiological change during embryonic neural
developments. They play key roles in neural differentiation, cell
migration and connectivity. Knock out a kinases and the brain doesn't
develop properly. For example, knocking out the gene for mDab1 (tyrosine
phosphorylated during embryonic development) in mice does nothing to change
the mice for the first week after birth. After that, they exhibit
increasing motor deficits and grossly malformed brains. Apparently, the
neural cells differentiate, but fail to migrate.
http://www.fhcrc.org/science/scientific_report/basic/jcooper.html
Edelman in 'Neural Darwinism' suggests neural systems develop according to
'neuronal group' selection. This provides a level of complexity left
'undetermined' by the genetic foundation. By binding Edelman's ideas to
Kock's, we get neuronal groups with binary signal processing at their
foundations (neural memetics).
The neural system is a self-determining organ, with its own developmental
memory founded upon its own mechanisms. Koch describes 15 potential memory
recording systems. The autophosphorylating kinases are simply the fastest
at changing from 'conducting' to 'non-conducting.' Going back to the mouse
example above, the observed lack of neural cell migration shows cellular
differentiation occurred (genetics) but not the normal migration (neural
memetics).
While you might object that migration of neural cells to proper locations
in the brain has little to do with cultural artifacts like Windsor knots,
the ability to create Windsor knots reflect physiological changes in the
brain of 'enabled' individuals, too. As an individual goes from 'blank' to
'Windsor knot' enabled psychological states, their brain changes, neural
cells extend themselves, connections are made. We are discussing a matter
of degree, not of kind.
Mark
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