Scientific American has just started a new series where scientists describe questions which fascinate them but which they don’t think can be answered by science.
The first article is by sleep and dream neuroscientist Robert Stickgold who wonders whether we could ever understand the significance of dreams.
The idea: Dreams often feel profoundly meaningful, bizarre experiences often interpreted over the centuries as messages from the gods or as windows into the unconscious. However, maybe our brains are just randomly stringing experiences together during sleep and investing the result with a feeling of profundity…
The problem: The difficulty in exploring this idea is that how meaningful something is might be too hard to measure. “It’s a bit like beauty — it’s in the mind of the beholder,” Stickgold says. “It’s not like heart rate or the level of electrical conductivity of the skin, which you have outside evidence of. If a person says something is meaningful, you’re not sure how to measure that, and you’re not sure how, if at all, that applies to others. One has to come up with a meaningful definition of meaningful.”
Link to SciAm ‘Too Hard for Science?: The sense of meaning in dreams’.
Mind Hacks 
I used to be with the idea that dreams are merely “screen savers” until I heard about the experiment (cannot remember the authors who conducted it) where people played a video game followed by sleep – after they woke they were better able to reach the next level. Aside from rest, the idea was that dreams allowed the users to problem-solve. The clincher was the finding that children have more primitive dreams (being chased by animals, etc) than adults, who dream more about troubles at the office, etc.
‘Measurement’… extremely overrated.
Beautiful and meaningful is different for everyone but there is still something in common: All those ones define it as beautiful or meaningful. Just like they define something as blue.
When I quit smoking I had wicked dreams of smoking followed by panic that I had “relapsed.” There was nothing “random” about these dreams.
I’m not sure that “meaning” of dreams is a meaningful question. Meaning is usually something we restrict to language. Such as, what is the meaning of this sentence. Asking what is the meaning of a dream is sort of like asking what is the meaning of a cloud or floaters in your field of vision. You can obfuscate all you want but there is nothing necessary to dreams. Yes, they may or may not be random but that doesn’t mean they have meaning. I suspect that to have a meaning a dreamer has to believe a dream has meaning. That definitely means it is unverifiable, and thus not a science, just like all religions. But believing something has meaning doesn’t mean it has meaning in any critical sense of meaning. Otherwise we can categorize being gullible and naive as being “meaningful” experiences. I would suggest that only learning afterwards that one has been gullible or naive is meaningful, not the experience itself.
I think we dream, because we are bored of sleeping.
@Mason Kelsey: Dreams can have “meaning” if they have content – semantic or semiotic – that is conveyed intentionally. When someone speaks of his dream having “meaning,” he usually speaks of it in terms of a communication. A part of him knew something that another part of him did not, or wished to emphasize something that he does not consciously pay much attention to. The dream may be interpreted as communication from God or some other external being.
Alternatively, the dream may be considered to have meaning if it is randomly assembled but is nonetheless susceptible to an interpretation that one finds significant. This, of course, would amount to calling a Rorschach test “meaningful,” and stretches the usefulness of the term beyond limits.
So to stick to the first way of viewing meaning, I would answer you that dreams may themselves be a kind of language, possibly a symbolic one. Just as I can write a letter to myself that I will only read in the future, and the letter is and ought to be considered to have some amount of intended meaning and some amount of unintended significance due to the circumstances of the reading, so might dreams be a way we retell ourselves narratives or even receive communication from parts of our brains that do not make their outputs known consciously. Some parts of the dream may be an intentional communication, and some parts unintentional. The fact that dreams are often remembered during the day when some other circumstance reminds us of the dream may lend to its alien quality, and imbue it with undue pertinence.
@Brannon Smith: Brannon wrote, “Dreams can have “meaning” if they have content – semantic or semiotic – that is conveyed intentionally. When someone speaks of his dream having “meaning,” he usually speaks of it in terms of a communication.”
So you say dreams must and do have three components: content, which conforms to a semantic or semiotic form, and is intentional. Certainly they have content, and they seem to have a semantic form that is unique to dreams. Your analogy to a language is plausible. I wonder if they can be said to be intentional unless dreamers directly control the content and script for their dreams. I guess some people can do that but most don’t. So intentionality seems to be an unnecessary part of a dream. In fact most people’s selves seem to have a passive role in dreams which indicates that there is no intentionality.
I also have problems with the idea that dreams are (always?) interpreted as a form of communications. Some people do interpret dreams that way, especially in a spiritual context. Of my own dreams, when I remember them, I have never felt them to be a form of communication of any type. I wonder how close the interpretation of dreams as communication is to hearing voices and not realizing they are from our own minds, caused by ourselves. I guess how one interpretes dreams or uses dreams is a clue to the mental waking state of any person. If true, the meaning we attach to dreams might be more like a indicator of our mental health awake.
@Mason Kelsey: I agree that not all dreams are meaningful, or intended. I disagree that you seem to equate intention with *conscious* intention; that is, intention that is explicitly known by the dreamer. Without descending into ego/id distinctions, I think we can agree that the brain performs many tasks that are outside of our conscious awareness and which are more complex than simple memory retrieval. Anecdotally, I have certainly had occasions when a fully formed idea “popped into my head” without having consciously worked it through. As the idea wasn’t random, and was directed toward some problem I had hoped to solve, I infer that my brain worked on the problem without my conscious awareness of it, and then communicated that result – however rough – to my conscious mind. This is the kind of communication I am talking about.
Even if our experience of dreams is passive, this has no bearing on whether it is a means of communication. It is also very possible that the dream is not the communication itself, but rather an effect of the communication.
I am not sure what you are getting at regarding our interpretation of dreams being some kind of measure of mental health; the way dreams are viewed is certainly informed by culture. In that sense, viewing dreams as being inserted into our minds by aliens or the government would be a possible indicator of paranoid delusion in our culture, whereas believing dreams to be divine communication might be normal in another culture.
I do want to emphasize that I do not mean that communication must be from outside to inside. And I suspect that how we view dreams has some effect on whether we routinely experience dreams as being nonsense or potential communications.
Thanks for your clarification on what you meant by “communication”. With that clarification we are in agreement although “communication” would not have been my first choice of words as I infer meanings that you might not have wanted to include, such as belief in some unverifiable source external to one’s own mind. Unfortunately, cognitive sciences and phenomenology are still working on an adequate and exact vocabulary as we continue to break consciousness into its component parts. So we tend to stumble with our communications. At least I do.