Dreams may have an important physiological function

Nov 12, 2009 by Lin Edwards weblog
A child sleeping (Sleep)
A child sleeping. Image: Alessandro Zangrilli, via Wikipedia.

(PhysOrg.com) -- Dreams have long been assumed to have psychological functions such as consolidating emotional memories and processing experiences or problems, but according to a Harvard psychiatrist and sleep researcher the real function may actually be physiological.

According to Dr J. Allan Hobson, the major function of the (REM) sleep associated with dreams is physiological rather than psychological. During REM sleep the brain is activated and "warming its circuits" and is anticipating the sights, sounds and emotions of the waking state.

Dr Hobson said the idea explains a lot, and likened it to jogging. The body does not remember every step of a jog, but it knows it has exercised, and in the same way we do not remember many of our dreams, but our minds have been tuned for conscious awareness.

Hobson said dreams represent a parallel consciousness state that is running continuously, but which is normally suppressed while the person is awake. Dr Mark Mahowald, a neurologist from Hennepin County Medical Center, in Minneapolis, said most people studying dreams have started out with fixed ideas about the psychological functions of dreaming, and try to make dreaming fit these ideas, but the new study makes no such assumptions.

In evolutionary terms REM sleep seems to be relatively recent, and has been identified in humans, other warm-blooded animals, and birds. Earlier studies have suggested it appears early in life, in the third trimester in humans, and research has produced evidence the brain of the may in a sense be "seeing" images long before its eyes are opened, so the REM state appears to help the brain build , especially in the visual areas.

This does not mean dreams have no psychological meaning, since they do at times reflect current problems, anxieties and hopes, but people can read almost anything into dreams. A recent study of more than one thousand people at Carnegie Mellon University in Harvard, showed that there were strong biases in how people interpreted dreams. So, for example, subjects attached more significance to negative dreams about people they disliked and to positive dreams about people they liked.

Research on lucid dreams has suggested that only 20 percent of dreams are about people or places we know, and most images are unique to a single dream. Lucid dreaming is the ability to watch a as an observer without waking up, and Dr Hobson finds support in lucid dreaming for his argument for dreams as a kind of physiological brain exercise. A study co-authored by Hobson and published in the September issue of the journal Sleep reported that elements of both REM and waking were apparent in lucid dreaming, especially in the frontal areas that are quiet during normal dreams. According to Hobson, this suggests there are two systems, which can be running at the same time.

The potential applications of the research may be a deeper understanding of conditions such as schizophrenia, which is categorized by imaginings that may be related to abnormal activation of a dreaming state.

The paper was published last month in the Nature Reviews Neuroscience journal.

More information: and dreaming: towards a theory of protoconsciousness,
Nature Reviews Neuroscience, 10, 803-813 (November 2009); doi:10.1038/nrn2716

© 2009 PhysOrg.com

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User comments : 12

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teledyn
4 / 5 (5) Nov 12, 2009
In the Anime "End of Evangelion" it is said that dreams do not replace reality, dreams EXTEND reality. The early 20th century mystic writer P.D.Ouspensky also insisted that the dream state does not vanish upon waking, but remains as a background, masked by our consciousness in the same way that the morning sun scatters light that hides the always-present starry skies.
frajo
2.5 / 5 (2) Nov 12, 2009
has been identified in humans, other warm-blooded animals, and birds.

"has been identified in humans, birds, and other warm-blooded animals" would have made sense.
superhuman
not rated yet Nov 12, 2009
And where is evidence to support his theory?
defunctdiety
not rated yet Nov 12, 2009
And where is evidence to support his theory?


Sensory deprivation. Look into it. Differing techniques have been used in everything from meditation to interrogation. In the meditative application, you are conscious (awake) but have 0 input from your senses i.e. floating in high saline warm water, in a sound proof, blacked out tank. Read user accounts of the experience (I would recommend Joe Rogan's :P), read research on it in all it's forms. Very intriguing stuff.

Also, I think about anyone who's take hallucinogenic substances (psilocybin, etc., which theoretically activate these parts of brain activity w/ the senses intact) would affirm such theories.

Not super scientific stuff, but infinitely more interesting, IMO.
JRDarby
not rated yet Nov 12, 2009
I marvel at how some people cling dogmatically to materialism the same way others cling to their religious beliefs. While I appreciate the research (as I appreciate any experimental research), I can't help shake the feeling the experimenter is trying very hard to eschew any notion that dreaming may have an important, non-physical/non-physiological component, purpose, or function that falls outside the purview of scientific orthodoxy.
frajo
1 / 5 (1) Nov 12, 2009
the experimenter is trying very hard to eschew any notion that dreaming may have an important, non-physical/non-physiological component, purpose, or function that falls outside the purview of scientific orthodoxy.

Per definitionem no object outside of the realm of scientific reasoning can be studied by science. The intersection of science and metaphysics is empty.
fuzz54
not rated yet Nov 12, 2009
I marvel at how some people cling dogmatically to materialism the same way others cling to their religious beliefs. While I appreciate the research (as I appreciate any experimental research), I can't help shake the feeling the experimenter is trying very hard to eschew any notion that dreaming may have an important, non-physical/non-physiological component, purpose, or function that falls outside the purview of scientific orthodoxy.


There would be no way to test the hypothesis that dreaming has a function that falls outside the purview of scientific orthodoxy.
superhuman
not rated yet Nov 13, 2009
And where is evidence to support his theory?

Sensory deprivation. (...) hallucinogenic substances...


I am well aware of the effects of both but I fail to see how it is supporting the theory that dreaming is a practice as opposed to dreaming as a random noise, dreaming as refreshing of memories and so on.
defunctdiety
not rated yet Nov 13, 2009
I am well aware of the effects of both but I fail to see how it is supporting the theory that dreaming is a practice as opposed to dreaming as a random noise, dreaming as refreshing of memories and so on.

My mistake, I thought you were asking for evidence to support the theory of P.D.Ouspensky, as put forth by teledyn:
"insisted that the dream state does not vanish upon waking, but remains as a background, masked by our consciousness"

Which Hobson also stated in the article: "Hobson said dreams represent a parallel consciousness state that is running continuously, but which is normally suppressed while the person is awake."
Lumina_Sprite
not rated yet Nov 15, 2009
It's wonderful to find that people actually exist that are not idiots. I'm so glad that people have open minds, here. It's so refreshing, compared to the dull high school melodrama that I am forced to wade through daily. This site is a god send.

I happen to feel that dreams as a function of mental house cleaning, organizing thoughts and feelings, is a rather scientific approach, and dreams could quite possibly have a deeper spiritual meaning. Not to dogmatically cling to any spiritual beliefs, or anything...just musing...
frajo
1 / 5 (1) Nov 15, 2009
I happen to feel that dreams as a function of mental house cleaning, organizing thoughts and feelings, is a rather scientific approach, and dreams could quite possibly have a deeper spiritual meaning. Not to dogmatically cling to any spiritual beliefs, or anything...just musing...

The problem with your "deeper spiritual meaning" is that it lacks the quality of falsifiability which is indispensable for scientific reasoning.
In a non-scientific context it could make sense, of course.
Fabian
not rated yet Nov 20, 2009
So it may be that dreams are a result of the brain being placed on "idle" like a revving car at an intersection waiting to move. The brain never stops processing information, real or imagined, twenty four hours a day. I'm interested in knowing how the researcher could even develop an experiment to verify this.

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