IUBio

Brain clues to attention disorder

John H. johnh at faraway.hgmp.mrc.ac.uk
Sun Dec 21 23:45:26 EST 2003


A good example of how semantics can fuck up our understanding. Thanks for
the detail Glen.


John H.


"Glen M. Sizemore" <gmsizemore2 at yahoo.com> wrote in message
news:582c15c5f1a4da1d5ffa3127f92df7fe at news.teranews.com...
> Whatever meaning might be given to the term "psychomotor stimulant," it is
> clear that the term is useless for describing the effects, on complex
> behavior in animals, of drugs like cocaine, amphetamine etc. and related
> drugs like methylphenidate (Ritalin). It has been noted for some time
that,
> in laboratory animal operant preparations, such drugs will decrease high
> rates of response maintained by food presentation, while increasing low
> rates of response, in the same subject within the same experimental
session.
> This led to the notion that the particular event maintaining responding,
> i.e., food, water, shock-termination (usually termination of a stimulus
that
> is perfectly correlated with shock-occurrence in the absence of
responding)
> etc. didn't matter in determining the effects of psychomotor stimulants -
> what mattered was the ongoing rate of response under non-drug conditions.
> Although it is now clear that there are a variety of circumstances in
which
> the so-called "rate-dependent" effects of psychomotor stimulants do not
hold
> (such drugs rarely increase the rate of punished responding, for example),
> it is still a fact that under a variety of circumstances the effects of
> psychomotor stimulants on positively- and negatively-reinforced behavior,
in
> laboratory animals, is an inverse function of non-drug rate of responding
> (and dose, of course; small doses of the drugs tend to increase low rates
of
> response while having no effect on higher rates; moderate doses will
produce
> substantial increases in low rates while high-rates will be reduced; high
> doses will, of course, decrease both high and low rates).
>
> <orkeltatte at hotmail.com> wrote in message
> news:84da9680.0312210247.4030f84b at posting.google.com...
> > > >The fact that Ritaline and other similar central stimulating drugs
has
> > > >the paradoxal effect of normalizing activity and attention in ADDH
> > > >conditions ,
> > >
> > > It is only paradoxical if we play a bit of word magic with
'stimulating'
> >
> > Sorry! But this is semantic bullshit.Paradoxal refers to an opposite
> > effect compared to the common effect on the majority of people - eg
> > excitatory, increased psychomotor tempo and activity and soforth.
> >
> > >
> > > >together with the findings of reduced cerebral bloodflow
> > > >(SPECT) on brainstem level , suggests not only a dysfunction in
> > > >attention centre (RAS) but also that it is the dopaminergic systems
> that
> > > >are malfunctious. It is therefore possible in the true cases of ADDH
to
> > > >treat ex juvantibus with these drugs , and confirming the diagnose.
> > > >
> > > >orkeltatte
> > >
> > > --                                                            .---.
> > >   It was once believed that a million monkeys at a million   { o o }
> > >   keyboards would eventually type the works of Shakespeare,  _(---)_
> > >   but the Internet has since disproved this theory.         /       \
> >
> > I am sorry - but you lost this monkey there - maybe my cognitional
> > capacity is to slow?
> >
> > orkeltatte ,
> > specialist in child and youth psychiatry amongst other things
>
>





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