I had an odd dream last night, which resulted in my thinking about dreams this morning. Dreams (like most of what goes on inside the brain) are poorly understood, which is great for people like me who like to have their opinions unsullied by facts.
I have a couple of theories about the nature dreams.
The first is that in our brain's storage mechanism is very heavily compressed.
To talk about compression, I'm going to introduce two terms: "information" and "data". Information is the abstract idea that needs to be stored, wheras "data" is either the symbols or (for the sake of this discussion) the actual physical tokens that do the storing. For example, "blue" is an abstract idea (information) which describes the colour of the ocean and sky, a type of music, and an emotional state. The letters "b", "l", "u" and "e" (in that exact order), or the number #0000FF or the letters "b", "l", "e", "u", "e" (French, in case you didn't already know) are all the data which is used to represent the information "blue". It's hard to explain in text, because when you read this, all you can see is the data. It's impossible for you to see the information, because the information is in my head. However, assuming you read English and I have written clearly, the information will also be in your head because we use the same rules for converting information to data and back.
You'll notice that one "unit" of information ("blue") is represented by different amounts of data. In English, there is a 4:1 (four letters to one concept) ratio, in French it is actually 5:2 (five letters to two concepts: the colour and gender). The goal of compression is to get that ratio as small as possible.
Let's focus just on English words for a bit. There are 11,881,376 possible 5-letter combinations of the English alphabet (starting at "aaaaa", "aaaab", and finishing with "zzzzz"). But according to my dictionary, there are only 6,112 5 letter words in English. This is extremely inefficient. Likewise, the English sentence "My wife, whom I love very much, is right next to me now." has 13 words, but really only 3 concepts (female-life-partner, adjacent-to-me, this-moment-in-time). It's also very inefficient. (The sentence is inefficient, not my wife. She is very efficient. Honest.)
Why is language so inefficient? The inefficiency helps with error correction. For example, if I turn off the spellchecker, I would have written "the inefficency helps ith error correction", and you would have known exactly what I meant. Because the letter sequences "inefficency" and "ith" are not valid English words, you understand that they are not what I meant to say, and you can infer the close English words that I did mean. Even if I did type valid (but incorrect) words, like "I brought pads, my stick, and three picks to hockey practice" you would know I was referring to hockey pucks, not ice picks. That is the advantage of redundancy in language. THe other advantage of redundancy is the ability to distinguish between completely random gibberish and valid information. For example, the phrase "Kelcjw qgvfw dizfn cmgxdva ip wt vyxs dnmypv nuxi tme koikph" uses the same letters as valid English, but it is completely meaningless. In other words, this phrase has 61 characters of data, but 0 units of information.
To summarize this digression, when you have redundancy in the way you store things, it is less efficient, but you gain the ability to correct errors, and detect gibberish..
Now, back to the topic of dreams. My theory is that the brain has such a highly optimized information compression scheme that all possible data represent information. In other words, there simply is no gibberish in the brain. Every possible sequence of proteins and arrangement of synapses (I'll call these "memory symbols") has a meaning. So when random activity does happen in the brain, we cannot detect it as gibberish, it has meaning. For example, the memory symbols for "family, place, fly and animal" happen to randomly occur during a dream, and our brain fills in the rest: "My pet dog and I were flying through our house." Add the random idea "fear" to it, and suddenly the meaning changes drastically to something that involves falling in a bottomless pit while you are unable to save your dog from a burning house.
I believe that not only does the brain have a storage mechanism that is has a valid meaning assigned to each possible storage unit, but I believe that it has multiple possible meanings (sometimes quite different) assigned to each storage unit, and the brain depends on context to figure out which meaning should apply. Just like "pin" can be a sharp metal thing, the act of holding someone down in wrestling, or your personal identification number associated with a bank card, I think a given memory symbol can mean different things to the brain. The brain usually deduces which meaning to apply based on the current situation and the symbols around it. That is why dreams, when they contain random symbols, are often quite surreal. That is also why they are so frequently about your current life, since the brain assigns meaning based on the other (real) memories that are around it.
