why study neurology?

Nick Medford nick at hermit0.demon.co.uk
Fri Jan 18 14:11:21 EST 2002


In article <43525ce3.0201180702.715f86b9 at posting.google.com>, mat
<mats_trash at hotmail.com> writes
>OK, if I've reasoned it down to two possibilities for what you (Nick
>and James) are saying:
>
>A) The mind is totally explained by the brain, but some mind-phenomena
>will not be mapped to one synapse or two - these phenomena will be
>explained by higher level mathematical description of the activity
>patterns across what might be vast areas of cortex - emergent
>properties if you want (if this is the case then I totally agree with
>you, in essence there is still nothing but the synapses or atoms or
>whatever, but just that we have to look at a collection of neruones to
>describe such higher level functions such as 'thinking')
>
>B) The brain is the substrate for the mind and the synaptic activity
>gives rise to an emergent mind which constitues of something else but
>the brain alone.  This is dualistic and I do not agree.
>
>Option A is exactly the stance that I take.  As an example: if shapes
>were represented in the brain by a pattern of synpatic activity
>actually in that shape.  If a trianlge were represented by 99 neurones
>all firing, and these neurones were distributed as a triangle with 33
>neurones making up each side.  Then looking at one or two synapses
>will not tell you what the brain is representing, looking at a higher
>level will.  However that description is only necessary in the study
>of the brain.  To have its effect all the representation of the
>triangle has to do is be causal in creating the right pattern of
>activity in the motor cortex so that we make the sounds that everyone
>hears as the word 'triangle'.  These sounds then cause a similar
>representation to the original one in the speaker's and others'
>brains, so that we all collectively agree on what 'triangle' means. 
>At no point in the actual physiology is a higher representation
>actually required becuase it is already there. The emergent
>description is only necessary in understanding because if that pattern
>is causal like ive described then the higher level description is
>implicit in its function.
>
>I'm not describing this very well but I hope you can see what Im
>trying to say.  I suppose its true of all things.  If a bullet is
>viewed at the atomic level you can't understand what it does, but if
>you characterize it at a higher level you can.  However that
>charachterization is only necessary to an observer

But surely without an observer then there isn't even an atom, let alone a
bullet. Equally, when you talk of neurons, synapses etc. you are speaking
as their observer. 

> because if that
>collection of atomes acts like a bullet then it is a bullet.  The
>emergent property is inherent to it.

Right, so you acknowledge that the concept of emergent property is at
least valid. So the question is then: is the property of "bullet-ness" (sorry
for such an ugly neologism) *the same thing* as the atoms of the bullet,
or is it something else? I would argue the latter, as a bullet has various
meanings, properties, functions (cf my table example earlier) that only
come about once you know what it is and what it is for. In other words
there is an informational realm as well as a physical one. This leads me
to interpretation B above - though I still don't agree that it's a dualist
position.

Supposing you have two objects which are exactly the same size and
shape, in fact are exactly the same, right down to the atomic level. But
they come from different cultures, and one is a bullet whereas the other
is a paperweight. Are you going to say that the second one is, in fact, a
bullet? Even though the concept of "bullet" has no meaning in that
culture?? Surely not. But it is exactly the same physically as the first
object- it only differs in terms of the meaning ascribed to it. So it differs
in emergent property, but not in physical structure. So there *must* be
another level besides the physical. This is the level of information.
Emergent properties depend on information as well as atoms.

Now, you may argue that like my fMRI of the leg example, this doesn't
quite work because we are discussing an object, and the meaning
attached to it comes from the brain. But this relates back to the idea that
it may be meaningless to discuss consciousness- or at least some of its
aspects- in isolation from the environment. After all it seems likely that a
brain with absolutely no sensory input can generate qualia- they depend
on interaction with environment.

This leads me to refine something I said earlier:

>>we have to ask ourselves whether someone
raised in complete social isolation could have the experience of, say,
"redness" (though obviously they wouldn't have that label for it).<<

What I should have said was "total sensory deprivation" rather than
"social isolation".

Could someone raised in total sensory deprivation ever experience
qualia?? I have no idea, but it seems at least possible that they might not.

Perhaps "informational", rather than "experiential", is a more precise
answer to your earlier question of "what is this extra level?"  (the level
of the emergent properties). 

Well, I may not have convinced you, but I've certainly convinced myself
:)

[footnote: The concept of information as a fundamental building block
isn't so outlandish- I know a number of physicists now subscribe to this
idea and there was an interesting article on this in New Scientist a few
months ago, titled (from memory) "The Dreams that Stuff is Made Of"- I
can find the exact ref if anyone is interested. George Johnson's book
"Fire in the Mind" discusses this idea too. For anyone who hasn't read it,
this is a fascinating book which provides a crash-course in quantum
theory as well as discussing the idea that science ultimately involves a
kind of faith, which again is pertinent to this discussion.]
-- 
Nick Medford




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