Are Dreams and Hallucinations Similar from a Neurological Perspective?

[Nuklear]

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?

 

[Cincinnatus]

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...

 

[mezarashi]

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 >_<

 

[light_bulb]

mess around with your serotonin levels and more than likely you'll be in a bad mood.

 

[denverdoc]

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 >_<

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.

 

[raolduke]

Dreaming occurs while you are sleeping and usually can't be remembered without device. Hallucination occurs while you are awake and its a conscious decision to hallucinate (most of the time).

 

[Nuklear]

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.

 

[Evo]

Dreaming occurs while you are sleeping and usually can't be remembered without device.

What do you mean "without device"?

Hallucination occurs while you are awake and its a conscious decision to hallucinate (most of the time).

When is a hallucination ever a conscious 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.

 

[LightbulbSun]

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 >_<

You're always dreaming when you're asleep. Sometimes you're not conscious to it, but just because you don't remember dreaming does not mean that you're not dreaming.

 

[Nuklear]

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.

 

[raolduke]

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.

 

[denverdoc]

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.

 

[Nexus555]

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.)

 

[Csimmonds]

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.

 

[denverdoc]

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 there's 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.




































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[raolduke]

The average person who doesn't practice dreaming or knows some secret art to sleeping can use chemicals. For the average person chemicals will can create a separate 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.

 

[Evo]

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.

 

[denverdoc]

The average person who doesn't practice dreaming or knows some secret art to sleeping can use chemicals. For the average person chemicals will can create a separate 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.

I'M sure there are some great sites to get into this, Erewhon (like there's 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 that's what interests you.

 

[light_bulb]

i'm now able to play director to my EPIC dreams, every night thanks to d2 and 5ht regulation.

 

[SynapticSelf]

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 derivative 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!

 

[Solidly-here]

Daydreams vs. Hallucinations

Depending on the day, I can have a powerful daydream.

One minute I am sitting there, the next minute I am lost in a daydream.
To me, this is what hallucinations are: vivid daydreams.

Many times, I have driven 20 miles, without actually being there to steer.
Yet, the car didn't crash.
I was lost in thought ... lost into a daydream (or lost into a hallucination).

 

[jiohdi]

1. everything we KNOW is a mental creation from diverse sensory data, so in a sense we are ALWAYS dreaming. 2. the primary difference between all states of consciousness is the level of awareness and memory and the believed source of data. The standard assumption is that normal view of the world is coming from our external senses, dreams are coming from semi-random synthesized memories and hallucinations occur when the boundary between thought/memory and sensory data is confused or merged.
It seems to me that the brain keeps sensory data at a higher level of emotional energy than thoughts/dreams most of the time, but that this mechanism can be altered by drugs, sleep deprivation, meditation, etc... and when the emotional level of a thought is on par with sensory data it will seem just as real as anything considered real.

 

[jiohdi]

as to WHY we dream, the current research suggests that dreams are part of several systems. 1. defragging sensory data. - we pay attention to so little of the total body sense data received, the sleep cycle can review the data for anything important we may have missed. often dreams do not seem to make sense when awakening, however they do often follow a logical progression by association rather than cause and effect time orientation. 2. test runs of brain systems offline after brain repairs and new learning has been installed. we often dream a lot and vividly just after learning something new and complicated. 3. a data dump cycle to weed out unnecessary data.

 

[raolduke]

How can you compare a day dream to a hallucination? Do you have auditory and full 3-d visual projections when you are day dreaming? Not to mention delirium.

I agree that hallucinations are filtered out perceptions, but are hallucinations limited to subconscious brain activity or can one actually create there own illusions?

 

[jiohdi]

How can you compare a day dream to a hallucination? Do you have auditory and full 3-d visual projections when you are day dreaming? Not to mention delirium.

I agree that hallucinations are filtered out perceptions, but are hallucinations limited to subconscious brain activity or can one actually create there own illusions?

a day dream is of lower emotional intensity than an hallucination, but can be tipped into full blown auditory and visual experience, even without getting that far it can make you NOT see what is right in front of you and have to do double takes or ask what did you say? they only differ by emotional energy content as far as I can tell...which drives the intensity of attention focused and the ability to exclude all other stimuli. there is something in psychology called 7 +/- 2 which refers to the seven objects we can pay attention to in any given moment. when emotions are normal we juggle many objects and don't even notice that only seven are being seen at anyone time... but when something attracts our attention strongly we can lock in on it with all seven and notice nothing else...or atleast not record it to long term memory. when that something is in memory or made up within, it can become the sole focus to the exclusion of all else and can sometimes seem as real as anything else called real.

 

[morson]

They're both altered states of consciousness, though the clear difference is that dreaming and day dreaming are naturally occurring and can't be induced, like hallucinations can from hallucinogens.

 

[8th Dumbest]

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...

What about when Dimethyltryptamine is released from the pineal gland?

 

[raolduke]

What about when Dimethyltryptamine is released from the pineal gland?

Then you will a really awesome time for a bit. Near death experience?
DMT can also be synthetically produced but only certain shaman have such knowledge.

I don't agree that day dreams can become as intense as a hallucination without losing consciousness.

 

[jiohdi]

I don't agree that day dreams can become as intense as a hallucination without losing consciousness.

you never actually lose consciousness at any time, but you do lose memory storage and retrival ability... you can be awoken at any time during sleep, for example and while you will not generally remember more than a few fleeting moments of dream or thought, you will sense that you were thinking all along... much of blackness of sleep is really a natural form of amnesia. If a traumatic event occurs right after another event, chances are you will be shocked out of remembering anything that occurred for the prior three minutes or so as your short term memory buffer would have been completely cleared to make way for the urgent incoming data.

 

[raolduke]

Repression.. Yes.

What can you conclude about those who can be affected by hypnosis?