From: mike@isgtec.com (Mike Sellers)
Newsgroups: talk.origins
Subject: theories of brain and mind (was Re: behavior and evolution)
Date: 16 Aug 92 20:30:20 GMT
Organization: ISG Technologies Inc., Mississauga Ontario

julian@fraser.sfu.ca (Julian Shillcock) writes:
> Thanks for the references, I'll see if the university library has them,
> and whether I can understand them( not a given!).

If you're interested in this area there are a lot of good books, but most
exaggerate there certitude in their titles.  Despite the claims of the
sociobiologists, for example, there is *extremely* little that is known
in any sort of scientific way about the relationship between evolution
and thought.  There are plenty of philosophical writings in this area 
(Dawkins, Wilson, and others being prolific folks), but almost no empirical
work.  Though dyed-in-the-wool sociobiologists will probably contest this
point, common things like altruism and homosexuality still require unusual
philosophical contortions, and are basically bereft of *any* direct evidence.
In their own way, the extreme sociobiologists are no more scientific than
are the creationists.

> I am reading a book
> on the brain called "Corticonics:Neural circuits of the cerebral cortex" 
> by M Abelese. Cambridge University Press. 1991. It is very readable.
> I have not got far but the first few chapters deal with the cellular 
> structure of the cerebral cortex. Without being arrogant (as a brain is 
> a lot more complicated than an metal) they are still at the level of 
> classifying cells by their shape, and staining them. 

This stuff is _basic_ to the understanding of even simple neural circuits;
it's like learning the colors on resistors in electronics.  Neurons and 
neural circuits are extremely complex even in the small scale -- when you
get to the large scale (e.g. the pyramidal system or the reticular activation
complex) things are too complex for our current understanding.  

If you're looking for readable yet reliable books on this and related 
subjects, I'd suggest

_The Universe Within_ by Morton Hunt
_The Synaptic Organization of the Brain_ by ?? Sheppard
_Principles of Neural Science_ by Kandel & Schwartz
and of course _Godel, Escher, Bach_ by Hofstadter.
Reading _The Selfish Gene_ (Dawkins) and/or _Sociobiology_ (Wilson)
wouldn't hurt either.

> I understand the neuron idea dates
> back to the 40s so I feel reasonably confident in saying we do not know
> much about the workings of the brain. At least that we do no have any theory
> with the predictive power of the theories of physics. 

That's right.  In 1984 or so, Zenon Pylyshyn wrote in _Computation and
Cognition_ (another good one) that cognitive science is currently much
like physics before Newton.  We have not yet found our Newton, much less
our Einstein, but who knows when some gifted grad student will come up
with a revolutionarily descriptive, predictive, and manipulable theory
that unifies our micro understanding of the neural world and our macro
understanding of the cognitive world?

> So I wonder what relation between the theories of very complex things
> like living beings, brains, evolution etc, and the "simpler" theories
> of physics, like Maxwell's equations is? 

Thus far there is no theory that explains what is known and predicts what 
is not yet known about the relationship (if any!) between evolution and 
complex living beings with anything _remotely_ like the exacting nature and 
far-reaching influence of major physical equations (e.g., Maxwell's work).

> Can someone explain the similarities between theories like evolution
> and the more mathematical theories of physics?

Probably not. :-)

> I can see that as one progresses up some scale of complexity the theories
> must become less precise and more ambivalent. So, for example, we can have
> QED which is the most accurate theory known, giving 8 or 9 decimal places
> for some constants. But it only deals with light and electrons! Any extension
> to other particles loses this power. Then you have  the Band theory of metals,
> which describes all the properties of metals very well. But except for
> some simple cases it is impossible to the calculations exactly, so one
> approximates. Then in stat. mech. one makes massive  assumptions
> that allow predictions to be made but at the expense of knowing exactly what
> the system is doing. I can see a trend here that as the phenomena being
> discussed become more and more macroscopic the theories become less
> and less mathematically accurate. 

The primary difference is that when employing statistical techniques to
physical systems, you have some idea (from previous work) what assumptions
you can make -- the shape of the "knowledge space" is to some degree known.
In evolution this space is less known; when applying it to something like
the attributes of complex creatures, and especially to cognition, this
space is almost entirely unknown.  Thus it isn't just a case of increasing
abstraction -- we don't yet know what we're abstracting *about*!

> ... I do not see any problem
> in my asserting that there are things in the world that no theory, let alone
> evolution at its current stage, will be able to predict or explain.
> It simply means therre are more things in the universe than we can know.
> BUT this leaves room for saying that there might be things in the universe
> that CANNOT be known by any scientific theory, viz God.
> The question is how can one find out?

There are at least two classes of facts which may be unknowable in any
scientifically meaningful sense: Those which represent phenomena that
cannot be detected or described, due to the nature of the physical 
universe (e.g., the position and vector of an electron), and those things
which do not have any apparent analogue in the physical universe, but
which are nevertheless important to us.  This last set is often the more
interesting, as it encompasses morality, ethics, and other ideas which
to pure reason may seem meaningless.  However, in even the most ardent
rationalist's life these non-scientifically-apprehendable ideas are what
form the very core of how they view themselves and the universe.  

> Ciao
> julian    

--
              Mike Sellers      User Interface Team Leader
           mike@isgtec.com      ISG Technologies, Toronto, Canada
              "Actum ne agas" -- Do not do what has been done.
                         Furare tantum ab Optimis
Newsgroups: talk.origins