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Medical Dream Vs. Hallucination

  1. Apr 23, 2007 #1
    I know there's plentiful similarities between a dream and a hallucination. But they're not alike. Besides dreams not making sense and rationale and also being not as vivid what are the differences between dreams and hallucinations from neurol point of view?
  2. jcsd
  3. Apr 24, 2007 #2
    One thing I can think of off the top of my head is that one way to get hallucinations is through activation of 5-HT2a receptors (this is what all hallucinogenic drugs do). This certainly isn't occurring during dreaming...
  4. Apr 24, 2007 #3


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    I thought dreaming itself is already a much debated topic. What causes us to dream in the first place? Some nights we dream, other nights we don't. I think that if we clarified this question first, it would then make the Dream vs. Hallucination comparison so much easier to construct >_<
  5. Apr 24, 2007 #4
    mess around with your serotonin levels and more than likely you'll be in a bad mood.
  6. Apr 24, 2007 #5
    Good question, tho I suspect we dream most nights if not every night. IIrc correctly, takes about 90 minutes to get there, and then the cycle repeats throughout the night, with a relatively small percentage of time spent in REM sleep. If so what accounts for the rare occasions where one has the same dream all night long? Or at least so it seems.
  7. Apr 24, 2007 #6
    Dreaming occurs while you are sleeping and usually can't be remembered with out device. Hallucination occurs while you are awake and its a conscious decision to hallucinate (most of the time).
  8. Apr 24, 2007 #7
    Yeah so I'm wondering are some parts of our brain not active when dreaming?
    This would explain why dreams don't make any sense and are really hard to remember.
  9. Apr 24, 2007 #8


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    What do you mean "without device"?

    When is a hallucination ever a concious decision? Do you mean by taking hallucinogens? For normal people that take hallucinogens, the "hallucinations" are nothing more than visual distortions, you won't actually see something that is not there like a horse or another person. People I've known that did see things that weren't there after taking a hallucinogen ended up being diagnosed with an illness such as schizophrenia and all spent time in a mental hospital. People with problems like schizophrenia have been known to see things that are not there.

    Denver Doc could probably explain brain disorders that cause hallucinations.
  10. Apr 24, 2007 #9
    You're always dreaming when you're asleep. Sometimes you're not concious to it, but just because you don't remember dreaming does not mean that you're not dreaming.
  11. Apr 24, 2007 #10
    You can have hallucinations by concentrating or mentall disorders liek Depression and Schizophrenia.

    That makes me wonder, when people remember things hypnotically are they hallucinating? WHen the hypnotherepist takes you under and you remember say being abducted by aliens.......is that your mind hallucinating? It would be odd for memories just to show up in your field of view and hearing elsewise.
  12. Apr 25, 2007 #11
    I didn't include brain chemistry. You would be suprised the things you can feel and see at high doses.. Even chemicals that are right under your nose.
  13. Apr 25, 2007 #12
    Evo is right. And probably everyone else in some way or another. Hallucinations are in the case of schizophrenia not under control, indeed this is a simple definition for psychosis--the inability to determine consensual reality from your own, I also think that it's possible, maybe even unavoidable to steer hallucinations under the influence of psychedelic drugs in a direction that is way bad.
  14. Apr 25, 2007 #13
    Actually, dreams are can be just as real, or more real than reality. An example is a dream in which you are flying. If you ever had one, when you wake up, you feel adernaline pumping and the sensation fading. The mind thinks it is actually flying, therefore it will produce the nessesary reactions to what it is dreaming.

    Another is a wet dream or a sexual dream. You wake up with a boner and when younger, stuff on your sheets. This is because the sensations in the dream to your mind are real, therefore you produce a real reaction.

    If you have ever lucid dreamed, you would know that ALL five of your senses are used whilst dreaming, and I've had lucid dreams that are more realistic than life (example I was once looking at grass in a dream. I could see each individual blade of grass. I bent down to look closer to find that I zoomed in and saw micro ogranisms on one blade leaf.)

    In a dream your mind uses the "mind model." This is a model of how you perceive the world (whether it be yourself, others, fears, sights, sounds, etc.)
  15. Apr 25, 2007 #14
    I don't know if it's quite relevant, but just as you're falling asleep you start to have visions or dreams whilst you're still just conscious. I have no expertise in this so I hesitate to say any more.
  16. Apr 27, 2007 #15
    These are the hypnogogic hallucinations referred to on a concurrent thread. It is a natural process and may relate to dreaming, but is kept separate because the Rapid eye movement isn't present. Plus the EEG's look a
    lot different so likely different processes at work. I had an interesting residency in psychiatry where about equal strength was given to the notion that dreams were more about small volcanos of unconscious magma coming to the surface and that close attention to these could pay huge dividends in understanding the need to pay heed to, versus strictly biological interpretations where it represented laying doen tracks of memory from short term to long term. I never bought into either side completely. I have had several dreams where I was able to get a glimpse of an insight into a scientific problem, or more often construe great murder mysteries or other topics for a book. Certainly nothing like Kekules snake image where he decoded the benzene ring problem. But theres more at work than just upgrading the hard drive. That much I am sure of. If a patient brings in a particularly vivid dream, we talk about it, but seldom do I encourage great weight. The dreams we have in the daytime seem more important.

  17. Apr 27, 2007 #16
    The average person who doesnt practice dreaming or knows some secret art to sleeping can use chemicals. For the average person chemicals will can create a seperate reality. Hallucinating is just unfiltering all the emotions, thoughts, and senses that your brain usually blocks out. Some strive for mystic experiences because they take so much more in when they are hallucinating. But it all depends on the chemical.
  18. Apr 27, 2007 #17


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    Discussions of illegal drugs and abuse of legal drugs for "recreational use" are not allowed here.

    Please limit posts to valid medical/health/societal impact related issues.
  19. Apr 28, 2007 #18

    I'M sure there are some great sites to get into this, Erewhon (like theres a tough anagram) being probably the most well known and quasi scientific. A great place to debate whether you actually managed to count Avagadro's number last night or you think you might have. Just funning, its a pretty interesting site if thats what interests you.
  20. Apr 28, 2007 #19
    i'm now able to play director to my EPIC dreams, every night :uhh: thanks to d2 and 5ht regulation.
  21. Apr 28, 2007 #20
    I don't pretend to be an expert, but I am very interested in dreams. As I understand it, dreams are simply our brain's quest to make sense of the process of LTP (during which we are "replaying" recent memories), and also, perhaps, "random" activity, or noise, in other parts of our brains. After all, no part of our brain is every completely silent, it's just that our (undefined) attention mechanism chooses what is and what isn't ignored during conscious states. I think that dreams are simply this mechanism struggling to make sense of activity that, as far as the brain is concerned, is derivitive of external stimuli. I suggest looking to attention for a true understanding of dreams.

    As far as I can tell, hallucinations are rarely experienced by the average, chemically balanced individual. I think that people use the term hallucination quite loosely, and in most cases they are referring to delusion, meaning that a brief inconsistency in sensory data occurs, and the person deludes themselves into believing that an object was seen, or a voice was heard.

    True hallucinations (as opposed to drug induced distortion) seem to be very closely related to dreaming, such as was mentioned: hypnogogic experiences. I have issues with insomnia, and, although it's a horrible habit, I rely on anti-histimines to lull me into synthetic slumber far too often. I notice that these hallucinations are much more prevalent after I've taken a sleep aid. I can almost guarantee that before drifting off I will hear a distinct voice or the laughter of a child or some such thing. If anyone has any knowledge on this, please expand!
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