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Medical Phobias and addiction

  1. Feb 10, 2006 #1
    alright for addiction.
    im interested in how addiction works. like do people get addicted to the act of doing, say smoking. or become so accustomed to the effect of the drug. such as relaxation. that you need a smoke for the effect. or does the chemical change your brain chemistry so that you essentially require a drug to keep going.

    as for phobias.
    im wondering with those cat scan graphs and stuff. is it possible to actually proved empirically what emotion or feeling a person is going through? Like ive brought this up before.
    Phobias
    Essentially. Like neurologically. could you tell why these are. and if they are true fear?
     
  2. jcsd
  3. Feb 10, 2006 #2

    hypnagogue

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    Not quite sure what you're asking-- are you asking whether people become addicted to certain behaviors rather than certain neurochemical states, or vice versa, or something else?

    In any case, it's pretty well established that addiction is established via dopaminergic activity in the mesolimbic pathway of the brain. Cigarette smoking is addictive because dopaminergic neurons in the mesolimbic pathway have nicotinic receptors (essentially, these neurons can be activated by nicotine-- see here for more). But even addictive behaviors that do not explicitly involve the intake of drugs operate via this dopamine pathway. For instance, recently it was found that administering dopamine agonists to Parkinson's disease patients had the unfortunate side-effect in some of inducing gambling addiction and other addictive behaviors (e.g. 1, 2).

    Manipulations of rat models in the lab have shown that the addictive process based in the mesolimbic pathway is not specific to particular kinds of behaviors. In other words, virtually any kind of behavior could potentially become an addictive behavior, so long as its neural foundations can "hook up" in the proper way with elevated dopaminergic activity in the mesolimbic pathway.

    I don't think we're at the point yet where we can deduce what someone is feeling just by looking at physical correlates. We can certainly make reasonable guesses, and for extreme cases of very strongly felt emotions we could proably make very good guesses, especially if we're just talking about a very coarse description of one's mental state (e.g. "is frightened or anxious" as opposed to "is very anxious and somewhat frightened and angry, but with a dash of hopefulness and resiliency, at future prospects"). But subjective experience and brain function are both exceedingly subtle and complex phenomena, and the nature of the relationship between the two is even more so.
     
    Last edited: Feb 10, 2006
  4. Feb 10, 2006 #3
    for addiction.
    im asking like. what exactly makes it addictive. I somewhat understand what makes the effect. but what makes it addictive.

    like the effect is what makes it addictive.

    ok for a example. you may be into Stargate atlantis. But ill shoot the storyline for example.

    Aiden Ford, he is fighting the wraith who suck the life out of you. the method of doing would kill the person quickly, so they have this life enhancer chemical pumped into the person. Aiden Ford gets fed on, but before the life gets sucked from him, but after this chemical is pumped into him. the wraith dies. so he basically gets chemically dependant on this chemical. he literally cant come off the drug directly. u need to ween him off slowly. while this is a tv show-fiction.

    does narcotics have the same effect? they change the brain chemistry so that addiction or dependance on the chemical is that way.

    instead of the psychological need for the effect.



    so with neurobiology. there isnt any sort of brain scan which shows a sort of graph which changes according to feeling, or brain activity?
     
  5. Feb 10, 2006 #4

    hypnagogue

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    I'm still not sure I'm completely clear at what you're asking. I think the prevailing explanation would be that a behavior becomes addictive when its neural representation in the brain interacts in the proper way with the dopaminergic neurons of the mesolimbic pathway. This interaction just has the mechanistic effect of compelling the animal to seek out and repeat the behavior.

    I don't think there is any distinction to be made between the neurochemical effect and the psychological need. It would be more accurate to say that the neurochemical effect manifests itself pscyhologically as the feeling of the need itself. For instance, humans who have had the mesolimbic pathway artificially stimulated with electrodes have reported feelings of intense interest and excitement. So the neural activity and the subjective, psychological feelings are not to be considered separate, but more like two sides of the same coin.

    There are various brain imaging techniques that do show reliable changes in brain function correlated with certain kinds of perceptual, cognitive, and affective tasks. So one might be able to say confidently what brain regions are involved with what kinds of tasks, but it's a trickier proposition to work backwards from the brain activity to the functional tasks. This is particularly the case when we're talking about whether something registers in consciousness or not, because often conscious states are only inferred indirectly from behavior.

    Logically, what brain imaging does is find relationships of the nature P -> Q (read that as "If P, then Q"), where P would be something like "mental task X is occurring" and Q would be "brain activity Y is happening." But if P -> Q is true, it doesn't necessarily follow that Q -> P is true. One has to find independent grounds for demonstrating the truth or falsity of Q -> P. This can be done in the cognitive neuroscience e.g. by administering neurochemicals or by producing artificial neural activity by electrical brain stimulation.
     
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