How Things Work: Dreams

Dreams can show people anything ranging from their ultimate desires to a nightmare they wish would never come true. But what nags many dreamers the most is the mystery of how dreams work.

Many psychological theories in the past have tried to explain the underlying dynamics of dreams. The first theory was given in the Victorian era by Sigmund Freud.
Freud believed that dreams help people act out what they cannot achieve in social settings; he focused on the significance of secret desires and symbolism in dreams.
Carl Jung, a young colleague of Freud, differed in his theory. He felt that dreams served to help solve problems or think over troublesome issues. To Jung, dreams related to thoughts similar to those people have while awake.

A more recent analysis threw out these older ideas. In 1973, Allan Hobson and Robert McCarley used their theory, activation-synthesis hypothesis, to explain how dreams are a result of random electrical brain impulses. The duo suggested that dreams are images pulled from experiences stored in memory. Hobson and McCarley hypothesized that humans do not dream in the form of stories. Once awake, the human brain forms stories out of the scattered images that a person views in his or her dreams, making sense out of the fragments of information.

This theory is widely accepted as one of the most prominent in its field.

Twenty years before this hypothesis was developed, University of Chicago graduate student Eugene Aserinsky helped to unearth some of the physiological reasons behind dreams. Aserinsky found that most dreaming takes place in the rapid eye movement (REM) stage of sleep, the fifth and last stage in a 90-minute sleep cycle.

In this stage, the brain activity is equal to or higher than what it is when a person is awake, while the rest of the body is essentially asleep. This is nature’s way of making sure that people do not enact their dreams. In recent studies, it has been shown that dreams can occur in any stage of sleep, not just REM sleep.

These include the first stage, when a person’s sleep is light; the second stage which shifts a person into a deeper sleep; and stages three and four, when people are in their deepest sleep. However, most people dream in the REM stage. During the night, humans go through these stages several times in cycles.

Humans experience stages one, two, and REM for the longest times in each cycle. By morning, the three stages may actually be acting out at the same time. Though they are seeing so many images, people do not remember their dreams, because the forward-thinking nature of humans makes this difficult.

It is believed that five minutes after the end of a dream, a person forgets 50 percent of it, and 10 minutes later, a person forget almost 90 percent of it.

Dream researcher L. Strumpell reasoned that it is natural to forget dreams because of the lack of association and repetition people have with them. If something is vague, unique, or not connected with any past experiences — which are the common characteristics of most dreams — the experience must be repeated in order for the dreamer to remember it. Thus, the dreamer does not recall such dreams.

Dreams have several functions that apply to a person’s day-to-day life.

One of these functions is ensuring uninterrupted sleep. While a person sleeps, minor external factors such as recurring thoughts and sound may affect the senses. The human brain interprets these triggers and incorporates them into dreams, thus not waking the sleeping individual. Also, as Freud once pointed out, nightmares allow people to become accustomed to unpleasant experiences they may have while they are awake.

Dreams may also function as a form of therapy, by providing people a means to enact suppressed desires as well as locate a comfort zone where everything works according to their personal preferences.

A rare form of dreaming, known as lucid dreaming, allows dreamers to control what they see in their dreams by telling themselves that they are actually dreaming.
In this case, the conscious control that people exercise over their dreams enables them to perform and subject themselves to actions that would be unlikely in real life.

A recent study showed that the abstract order of images and illogical flow of events in dreams fortify the connections between different cognitive parts of the brain.
It may also help the consolidation of semantic memory, the retention of knowledge that was not derived from specific experiences in the past.