To understand the dream process, we must first describe the basic sleep cycle.
Most people dream at least four or five times each night. About ninety minutes after falling asleep, we typically enter that stage of sleep marked by rapid eye movement (or REM) activity.
Although dreams can appear during other sleep stages, it is during REM that our dreams generally occur. Laboratory sleep research shows that most sleepers, when awakened from REM sleep, will usually recall a dream.
At the beginning of the night, our first REM period may last only five minutes; toward the end of the night, a REM period may last as long as thirty minutes. This stage of sleep is marked not only by rapid eye movements but also by a loss of muscle tone, sexual excitation, and brain waves resembling those that characterize wakefulness.
The reason for REM sleep is unclear, but it may facilitate memory storage, maintain brain equilibrium during bodily repose and, among infants, may accelerate the development of the brain and the coordination of the eyes.
All of these potential goals of REM sleep indicate that its psychological activities are superimposed on more primary biological functions. While dreams may assist the dreamer to become aware of life issues, identify personal myths, and solve problems, these psychological activities are secondary to the biological purposes served by REM sleep.
According to one widely-held theory, during a REM period, a cascade of potent chemicals (including seratonin) is released. This stimulates the visual and motor centers of the brain, evoking the dreamer’s memories. No matter how they are elicited, it is these memories that the dreaming brain uses as building blocks for the dream—recombining them in original, vivid, and often baffling ways to create a story.
The dreaming mind may create the story by providing a script that has been waiting patiently for the material that would allow it to surface, or by producing an on-the-spot narrative that matches, as best it can, the images that have been kindled.1 In either event, the dreaming brain appears to have remarkable self-organizing properties that create several more or less coherent stories each night.
Some dream stories reflect basic problems in daily life with which we have wrestled for years, stories that hold deep meaning for the dreamer. Other stories may be more trivial in nature, reflecting events of the past few days or hours that surface as “day residue.”
Still others may be little more than a jumble of disparate pictures and events, lacking any coherent theme. Regardless of the type of dream story presented, the story-making process can be likened to what transpires when we use language while awake. In fact, dreams are often called the language of the night.
We can define dreams as a series of images—reported in narrative form that occur during sleep. Our mental and emotional processes during dream time are, in many ways, quite similar to those we experience during wakefulness.
In one study people were asked to make up a dream while awake.
Surprisingly, the judges could not discriminate these imaginary accounts from the written reports of nighttime dreams. Both contained similar imagery reported in a narrative form.