From: bill@nsma.arizona.edu (Bill Skaggs)
Newsgroups: alt.drugs,talk.politics.drugs,sci.psychology
Subject: Re: instant addiction?
Date: 22 Jul 92 04:18:19 GMT
	<1992Jul21.052839.28725@bradley.bradley.edu>
	<1992Jul21.011754.9822@news.cs.indiana.edu>
	<1992Jul21.192412.3344@bradley.bradley.edu>
Organization: ARL Division of Neural Systems, Memory and Aging, University of
	Arizona


dave@bradley.bradley.edu (David Vessell) writes:

   dave@bradley.bradley.edu (David Vessell) writes:
   >I agree that a lot of this is a matter of semantics.  To me,
   >'addicted'  implies that certain behaviour is conditioned to the
   >point of compulsion and, by that definition, it can't happen in
   >one trial.  At the very least, a person would have to use a drug
   >3-4 times to set up the compulsion. 

Usually it requires dozens of exposures.  The controlling factor seems
to be the time delay between the behavior (i.e. taking a drug) and
activation of the brain's pleasure center (the neural pathway leading
from the ventral tegmental area of the midbrain to the nucleus
accumbens).  Crack cocaine causes very fast activation -- within a few
seconds -- and can sometimes lead to addiction in 3-4 exposures or
possibly even fewer.

   "Paul Hager" <hagerp@iuvax.cs.indiana.edu> writes:
   >Although I tend to agree with statement, I should point out that
   >there is a phenomenon called the Garcia Effect (I trust I got that 
   >right).

Yeah; nowadays it's more commonly called "conditioned taste aversion".

   paul:
   >In essense, a conditioned response can be set up after only one
   >trial.  The effect is observed when animals are given "tainted"
   >food.  There is no need to further condition them against that
   >particular food, the one trial suffices.

Slight technical correction:  the food is not tainted; the animals are
given perfectly good food and then some time later they are given a
drug (most commonly lithium chloride) that makes them ill.  As a
result, they develop an aversion to the food.  (Of course, in nature
this mechanism no doubt functions to make animals avoid poisons.)

   paul:
   >When this phenomenon was first observed, it 
   >created a great deal of consternation among the behaviorists. 

Did it ever!  One well-known researcher was overheard to say, "These
findings are no more likely than birdshit in a cuckoo clock".

   paul:
   >I'll
   >leave it to others on the net more familiar with the field to
   >comment but, suffice that it is not unreasonable to posit a
   >mechanism that "instantly" conditions a response given that such
   >an effect has already been observed.

   dave:
   >The phenomenon is also called aversion response, I believe.

It's called "conditioned aversion" or "avoidance learning".

   dave:
   >This response, however, has almost exclusively been observed in
   >negative, and frequently life-threatening, situations such as
   >tainted food and fear of heights.  This response, which may almost
   >qualify as a reflex of sorts, *has* been used to treat alcoholics
   >by giving them a nausea inducing drug and then letting them drink
   >their favourite beverages.  They become sick soon after, and their
   >bodies are fooled into thinking that the alcohol caused the
   >sickness, and future attempts to drink cause the person to be sick
   >again and thus be trained away from drinking. 

Yeah; but the general consensus is that it doesn't work very well.
The problem may be that it's hard to induce an aversion to a familiar
taste, and alcohol is pretty familiar to most alcoholics.  

   dave:
   >However, because of the utter lack of observations of this type of
   >response to positive or 'non-negative' situations, I would be
   >extremely hesitant to  apply this to drug use.

You are right to be hesitant.  Conditioned taste aversion has some
very special properties, and there is a decent amount of evidence that
it is produced by a special neural mechanism, not involved in any
other kind of learning.  There is also reason to think that one-trial
active avoidance learning in general involves mechanisms different
from those that come into play in positive learning.

   dave:
   >I don't know of any reputable studies that have ever observed a
   >reverse 'aversion response' to positive stimuli. 

A better way to put this might be that nobody has ever observed
one-trial learning to a positive stimulus; but if you put it that way,
it would be wrong.  Positive one-trial learning *does* occur, quite
commonly.  Still, one-trial learning does not necessarily mean
addiction.  Addiction is a difficult thing to operationally define in
the first place, and there is no way I know of to infer it from the
results of a single trial, so even if one-trial addiction could occur,
it would be hard for us to tell.

But even having said that: I bet if you rigged a button so that when
somebody pushed it, they'd immediately have the most intense orgasm of
their entire lives, at least a few people would be addicted after a
single push.

	-- Bill
Newsgroups: alt.drugs,sci.med