How Dreams Work

Why do we dream?

Well, that's the question that has really been unanswerable. Many people have suggested different reasons. From an evolutionary point of view there have been speculations that [[KW]] dreams [[/KW]] have evolved to periodically make sure that everything is working in the central nervous system and to be alert, alerted in a way that one could be responsive to danger in an environment. For example, if a person dreams that someone is breaking into their apartment and they see a hand creeping in, and then they suddenly wake up and realize that there is a strange noise, there is something happening that their dreaming mind has picked up first. But it doesn't explain all dreaming.

The current thinking is that dreaming is an important component of memory and that we do know that when people are learning new things, they take a language immersion course, for example, dreaming literally increases. Dreaming increases when we're learning new tasks, and if we're prevented from dreaming after we've learned something new, our memory for it is very poor. Even if we're allowed to sleep, but our dreaming is interrupted. There is a lot of evidence now that suggests dreaming is an important component of short-term memory. So, this is one possibility and perhaps one that's quite important. But, the bottom line is we truly don't know why we dream.

How do dreams and dreaming change through different stages of life?

The amount of dreaming varies over our lifetime. We dream in the womb, by the way. They've measured fetuses eye movement, which appear to be similar to what they have after birth. Whether they have images that accompany the experience we don't really know because we can't talk with the infant or with the fetus.

The earliest documented dream where there are images accompanying it is an 18-month-old child whom a researcher heard speaking in their sleep. After the child woke up they told the researcher about the dream. At that age a child can talk about the dream. With newborns there's a tremendous amount of the physical component of dreaming. About 80 percent of the sleep time of the neonatal infant and the newborn infant is in the REM(see the next section) state.

As we get older, that shifts. For an adult, approximately 20 to 25 percent of sleep time is in this REM state. Now you must understand there are theories that we dream constantly through the night, that the REM periods are just like the peaks of the mountain during the dramatic dreaming and we're kind of thinking-dreaming all of the time. But these dramatic peaks occur about 20 to 25 percent of an adult dreaming. In old age there is a reduction so that it goes down to more like 20 percent or there about. It not a huge drop, but from birth to adulthood there's a big reduction.

Is dreaming helping to form the brain? It's part of what we don't yet know. So in terms of amount of REM there is definitely an overall change from very large right after birth to 25 percent or so as an adult to less. If we sleep for 8 hours, that would be an hour and a half of every night that is spent in dreaming. For the older person if they sleep eight hours that would be more like an hour. But we're still dreaming.

Then there are increases in dreaming that occur in special circumstances and those being when we're learning a new skill, regardless of the nature of this skill. Any time that we have to really concentrate on something really increases our dreaming. It's probably good for us to keep learning new skills and exercising our [[KW]] brain [[/KW]] in that way.

There seems to be a link between hormonal levels and the amount of dreaming, so two great spurts of dreaming are at adolescence and during pregnancy, when there are literally more dreams taking place.

The dreams throughout a woman's [[KW]] pregnancy [[/KW]] somehow vary in content according to the development of the fetus. Dreams during early pregnancy often deal with becoming pregnant and your reactions to it or sometimes even learning of the pregnancy. Early pregnancy dreams also often contain a lot of water and aquatic animals. Many women report swimming or that there are fish or tadpoles. They're not consciously thinking about this but fluids are gathering in the womb and the dreaming is reflecting this aquatic state of the fetus. And then in the second trimester dreams tend to include lots of cute baby animals.

In the later third trimester dreams tend to contain larger animals, sometimes threatening animals, such as gorillas — and of course babies. But there is a changing animal component that accompanies the development of the fetus. Also, architecture changes in the woman's dreams. So that it changes from small buildings to large building at the end, such as big skyscrapers and such. There is an interesting dream life that accompanies the experience of pregnancy. This seems to accompany her sense of things getting bigger.

There's often a lot of practiced birth in that last trimester — Braxton Hicks contractions — and that is picked up in the dreaming mind and there are dreams in which the woman may actually be having the baby. It feels very real and it's a kind of practice that the mind is preparing for, sometimes the worse. These dreams can be anxiety producing. A lot of woman have these horrible dreams, and ask, "Is that normal?" And the answer is yes. First moms in particular are more prone to have anxiety dreams. There's one study that seems to show that the more anxiety dreams you have during pregnancy the shorter and easier is the delivery. The author's belief is that the women were mastering this experience in fantasy, that they were preparing themselves.

What do our dreams mean?

For centuries, we've tried to figure out just why our brains play these nightly shows for us. Early civilizations thought dream worlds were real, physical worlds that they could enter only from their dream state. Researchers continue to toss around many theories about dreaming. Those theories essentially fall into two categories:

• The idea that dreams are only physiological stimulations
• The idea that dreams are psychologically necessary

Let's take a closer look at these theories.