Brain clues to attention disorder

Dave Bird dave at
Sun Dec 21 14:27:32 EST 2003

In article<84da9680.0312211037.72881ab7 at>,
orkeltatte at <orkeltatte at> writes:
>Dave Bird <dave at> wrote in message 
>> In article<84da9680.0312210247.4030f84b at>,
>> orkeltatte at <orkeltatte at> writes:
>> >> >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.
>>  Let me explain.  The effect is not ACTUALLY paradoxical if we
>>  examine carefully.  There is only an APPARENT paradox if we 
>>  carelessly use the word 'stimulant'  without specifying 'of what'.
>>  "The fact that a (reflection-) stimulating drug abates a
>>  (movement-) stimulating disorder is APPARENTLY paradoxical
>>  until we realise that they stimulate different and opposing factors"
>Still playing with words

 On the contrary, I would think that describing as "paradoxical"
 two effects which are not directly opposed is playing with words.  
>>  I would reserve the word paradoxical when it genuinely the
>>  same quantity involved: "how is it that a patient with HIGH DOPAMINE is
>>  clearly showing and EXTRA-PYRAMIDAL TREMOR  from low dopamine effect?";
>>  "how is it that problems which began with RAISED SEROTONIN are now
>>  cleared up by INCREASING SEROTONIN LEVELS?"; etc.
>That will probably be due to the effect of up - and downregulationg of
>the receptors in question - adapting, or trying to adapt to new
>neurochemical environment

 Well, yeah, something like that.  Stress effects are what pushes down
 dopamine, and noradrenaline comes up in response: the result is that
 the person seems impulsive and physically active with little planning.

 Support planning (dopamine) and things come back into whack. 


In article<582c15c5f1a4da1d5ffa3127f92df7fe at>, Glen M.
Sizemore <gmsizemore2 at> writes:
>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 

 Rewarded responding is just a different chemistry, I suppose.

>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).

 Um, there are two ways of looking at what happens in ritalin 
 reducing high levels of movement activity.  One is that activation
 is something you "fill up to the over-flow mark", which precipitates
 a negative feedback when the drive is too high: add more drive to high
 activation and you may predominantly just push the negative feedback
 to reduce activity.  The other in ritalin is that the activation
 increased is different from and opposed to the activation it opposes.

 I prefer my version because it better fits the observed facts,
 but both effects exist.   

 8====3  (O 0)    GROETEN --- PRINTZ XEMU EXTRAWL   no real OT has
          |n|    (COMMANDER,  FIFTH INVADER FORCE)   ever existed 
 A society without a religion is like a maniac without a chainsaw.

More information about the Neur-sci mailing list