Date: Mon, 14 Jun 1999 09:28:30 +0200
From: "Gatherer, D. (Derek)" <D.Gatherer@organon.nhe.akzonobel.nl>
Subject: RE: Psychedelics and memes
To: "'memetics@mmu.ac.uk'" <memetics@mmu.ac.uk>
Chris:
When we review the developmental processes involved in information
processing so the dendrites-axon interaction is repeated at the next scale
in the form of neural networks that synchronise and function as if a neuron.
Derek:
Yes, I hadn't thought of neural networks that way before, but now that you
mention it, their integrative all-or-nothing output properties are
reminiscent of neurons......
Chris:
This seems to have been abstracted 'all the way up' to the level where these
interactions are expressed in the 'object/relationship' categorisation
system we see in the neocortex.
Derek:
I'm still not sure I can swallow this next step. For instance PET scanning
has revealed that different parts of the brain are activated when an object
is named aloud, named silently, seen but not named etc. [Incidentally I
think that this is an important piece of evidence against internalist
memetics, but that's a digression]. The point
I am making is that even object categorizations alone are diffuse and
difficult to pin down.
Chris:
The development process of the brain-mind reflects complexity at work where
feedback processes lead to the 'emergence' of 'new' structures that have the
SAME general methods of functioning as those processes from which they
emerge but with 'refinements' (abstractions) that come about as a result of
the more refined context that is able to support them.
Derek:
This is not implausible, but I'm not sure how one would test such a theory.
It seems too unspecific. For instance...
Chris:
For example, when we analyse the general behavioural characteristics of the
so-called reptilian brain we see characteristics that are reflected at a
finner level in the left hemisphere of the neocortex -- waypoint mapping,
conservative, tried-and-true methods, 1:1 behaviour (stimulus leads to the
same intensity of response regardless of scale.)
Derek:
Again I agree, but what does this tell us apart from the fact that our
brains are a little more sophisticated than those of reptiles?
Chris:
Sperry's error was in seeing the left as all parts and the
right as whole. Not true. The left is all objects and the right all
relationships.
Derek:
Really? Do Davidson and Hugdahl actually say this?
Chris:
Read the literature produced by the drug companies (e.g. producer of Prozac
(product name for fluoxetine)) another source is the usual refs. e,g, :
Dowling, J.E.(1998) "Creating Mind: How the Brain Works" NORTON for example
"[prozac] potently and selectively inhibits serotonin uptake.."p54 (BTW
Dowling is a Prof at Harvard so he must know something... I think..:-))
Derek:
Yes I'm well aware that Prozac is an SSRI (serotonin-specific reuptake
inhibitor), but I'm not sure how this supports your hypothesis. The main
use of Prozac is as an antidepressant, and isn't relevant to the
psychosis/psychedelia contrast that we started of discussing on Thurday.
It's not even clear how Prozac exerts its antidepressant effect. Like most
SSRIs Prozac has a therapeutic lag, ie. it takes a while for the effects to
build up, so the initial increase in synaptic serotonin concentration that
Prozac produces may not be the proximate cause of the antidepressant effect.
Chris:
FYI 'God in the head syndrome" is also known as "runner's high" and results
when serotonin uptake 'collapses' and the system gets flooded with the
stuff. Uptake is too slow (none at all!? :-))
Derek:
No, I'd have to disagree there. Runner's high is most likely to be
endorphin mediated. AS the Prozac work has demonstrated serotonin uptake
effects would be too slow to produce the runner's high which acts within
some 30 minutes or so.
Derek: (previously)
>Serotoninergic receptor non-specific blockers do seem to also block some of
>the effects of LSD, but I don't know if you can read too much into that....
Chris:
I think you can. When you analyse something the initial characteristics
detected, although 'raw' and 'general' will always be there no matter how
much you 'dig' and attempt to brush them aside. There ARE two threads at
work 'in here' and their characteristics determine all that follows....
Derek:
I'm still not convinced. My attempts to 'dig and brush them aside' are
actually attempts to make the necessary connections. I can't agree yet that
"There ARE two threads at
work 'in here' and their characteristics determine all that follows...." I
can see that the post-Sperryian ideas may still be valuable, but I can't see
any evidence to link them with what we currently know about neurotransmitter
pharmacology.
For instance, you say..
Chris:
The depression link is to the RIGHT side and is tied to serotonin pathways
that do seem to be more right thread oriented than left and so will appear
in the largest expression of right-thread characteristics, i.e. the right
hemisphere of the neocortex.
Schizophrenia is more LEFT oriented where the 'excluded middle' suddenly is
given 'random' preference that can be frightening to a 'left biased'
individual -- 'strange' connects are made and the independence bias makes
this all very 'strange' -- at times psychotic... (the left is also the
source of the concept of 'randomness'... if drugs play with this I think you
can see the potential affects on cognition!)
Derek:
For instance I would prefer to take the view that schizophrenia is a problem
with the dopaminergic system. I don't think that we need Sperry at this
juncture. In the absence of any firm connection between the pharmacology
and the neuropsychology, it's best not to make too many quantum leaps of
logic.
===============================================================
This was distributed via the memetics list associated with the
Journal of Memetics - Evolutionary Models of Information Transmission
For information about the journal and the list (e.g. unsubscribing)
see: http://www.cpm.mmu.ac.uk/jom-emit