Dr. Imre Bartfai wrote:

> the connection between caffeine and the frequency limit of flicker
> detection of the retina fascinates me (I believe it and I think I had
> experienced it).

  I'm interested in these stated effects of caffeine and nicotine.  The
Australian TV science show "Quantum" (not to be confused with "Beyond
2000") is presently re-running a series (probably BBC or such) called
"What's Your Poison?" about various popular drugs.  Nicotine is supposed
to make rats smarter for example and caffeine to do useful things.

  When they come out with these studies, or at least report them on
these shows, I'm never quiite sure how much they take accomodation into
account.  Take caffeine; OK, so it makes the retina respond faster; that
is, you give someone some and they can see faster flicker than they did
without it.  Fine.  You give it to someone who practically never
consumes it (like, incidentally, myself!) and *they* see flicker faster
than they did before.  Fine.

  What I want to know is; does the person who takes it all the time
perform significantly better *with* it than the person who never takes
it, *without* it.  My suspicion is that once the person *habituates* to
it, their "better" performance when drugged normalises so that in fact,
they are only a little better than they originally were, but definitely
sub-normal when non-drugged.  That's certainly how a lot of things, for
example narcotics, work.

  Cheers,
        Paul B.