Copyright © 2007-2018 Russ Dewey
Dreams occur in both REM and non-REM sleep, if the word dream refers to mental processes during sleep that a person can report upon awakening. REM periods apparently stimulate dreaming because REM sleep is a very active state accompanied by all sorts of biological changes.
Brain-scanning studies suggest that dreaming itself, as experienced by humans, occurs in a circuit involving the prefrontal cortex. Activity in that area correlates 100% with dreaming.
By contrast, REM sleep correlates 70-80% with dream activity. That is a strong correlation but it shows that REM sleep and dreaming are not identical.
Where in the brain does dreaming take place?
A classic finding from the Golden Age of Sleep Research is that very different sorts of dreams occur in REM and non-REM sleep stages. Judges presented with dream reports from REM and non-REM sleep have no trouble sorting them into two piles with high accuracy.
The weird stories are almost always REM dreams. The fragments of normal thought are almost always non-REM dreams.
In other words, REM dreams are like a narrative or story in which one is a believing participant. This feeling of participating in another world perhaps indicates that executive circuits of the forebrain are engaged in the dream narrative.
What are typical qualities of REM and non-REM dreams?
Non-REM dreams, by contrast, feel like ordinary thinking. They are not like being in a different world. They are more like thinking about recent events.
People in non-REM sleep sometimes deny they have been sleeping at all, even when they have been snoring with their eyes shut. Perhaps this is because (1) people do not notice falling asleep, and (2) their thoughts remain similar to normal waking thoughts.
Common Dream Themes
Certain types of dreams are found in all human cultures. Compare the following lists of dream themes, one from college students in the United States, the other from people on the Solomon Islands (located in the South Pacific, east of Papua New Guinea). They are very similar.
|Dreams by college students
(Most to least frequent)
|Dreams by Solomon Islanders
(Most to least frequent)
|Being attacked or pursued||Death and spirits of the dead|
|Falling||Incidents in everyday life|
|Trying again and again to do something||Incidents with sexual implications|
|Schools, teachers, studying||Food and eating|
|Sexual experiences||Fighting, beating, or being beaten|
|Arriving late for some event||Incidents involving animals|
|Eating delicious food||Being frozen with fright|
|Being frozen with fright||Going on a journey|
|Dead people as though alive||Climbing a hill|
|Flying or soaring through air||Sleep|
|Wild violent beasts||Trying to move but being fixed|
|Being unable to move||Physical disabilities|
|(From Tart, 1973)||(From Lincoln, 1935)|
These lists were collected from different populations in different cultures, 40 years apart. Yet they contain many of the same themes.
What are dream themes common to college students of 1973 and Solomon Islanders of the 1930s?
Of course, some of the categories are different. The theme of being attacked or pursued, in the Solomon Islander list, might correspond to fighting or being frozen with fright, in Tart's list, and so forth.
Nevertheless, you can see that people on opposite ends of the earth from different cultures had similar dreams. They dreamed of food, falling, sex, dead people coming alive, being unable to move, and animals.
Dream Recallers and Non-Recallers
Research has confirmed that everybody dreams, usually four or five times a night. People who say they "never dream" have as many dreams as other people.
Non-dream-recallers simply wake up more slowly and lose touch with the mental activity occurring during sleep. If forced to awaken suddenly, they often remember dreams.
Dement (1960) told how people who claimed they never dreamed were awakened during an REM period. They were startled by vivid thoughts, feelings and images of dreams experienced for the first time.
Students who seldom recall dreams can partially replicate this experiment by setting an alarm to awaken them about an hour after they fall asleep. If the student is mentally prepared to grasp whatever is in consciousness, when the alarm sounds, he or she may remember a dream.
What did Dement discover, when he tested people who said they never dreamed?
Why do some people consistently remember their dreams, while others do not? According to researcher Roseanne Armitage of Carleton University in Ottawa, EEG records in the sleep laboratory can distinguish "high recallers" and "low recallers" easily.
Low dream recallers experienced a large shift in electrical activity between brain hemispheres when they were awakened from rapid-eye-movement sleep. It is as if the two hemispheres were knocked out of balance," Dr. Armitage said. "For them, sleep and wakefulness are as different as night and day."
How did Armitage explain why some people do not recall dreams?
High dream recallers, she said, experienced little electrical disruption between hemispheres when awakened. For them, there was continuity in brain processes in the transition from sleep to wakefulness. (Blakeslee, 1988)
Eye and Body Movements Related to Dreams
In one famous case from Dement's sleep laboratory, sleep researchers noticed a series of large, up and down eye movements in a person during REM sleep. They woke the sleeper, who reported dreaming about walking up some stairs.
In a similar case, a sleeper was awakened after strong horizontal eye movements. He said he was watching a table tennis match in a dream.
In these cases, there seemed to be a clear relationship of dream content to eye movements. Notice these eye movements were not the bursts or vibrations of the eyes that define REM sleep. They were slower, like normal eye movements.
As it turns out, these early findings were unusual. Most sleep lab studies fail to show any relationship between eye movements immediately before awakening and dream content.
What are famous examples of eye movements related to dream content? What did later studies show?
Muscles often twitch or jerk during the falling-asleep process, especially after a day of heavy exercise. These twitches are called myoclonic contractions or sleep myoclonus.
Myoclonus is a medical term referring to shock-like contractions of a portion of a muscle. Indeed, many people use the word "shock" or "jolt" to describe these sudden movements. Some scientists say myoclonic contractions while a person is falling asleep are the result of metabolic activity in recently exercised muscles.
What are myoclonic contractions?
In some cases there is no denying the relationship between dream content and muscle activity. This is especially obvious when strong imagined activity breaks through the relaxation of sleep and awakens the dreamer. A student reports:
Recently while surfing in Florida, I had myoclonic contractions. My friend noticed that every night after a full day of surfing, I would kick my legs straight out and my arms would twitch.
While these contractions were going on I was dreaming about surfing and would actually go through the motions. Whenever I would fall off my surfboard I would have one quick, violent muscle contraction and wake up. [Author's files]
Goleman and Engel (1976) offered a simple explanation of myoclonic contractions. They said strong motor responses probably occurred when a sleeper interpreted the onset of profound muscle relaxation as loss of control (like falling off a surfboard) so the dreamer responded with sudden movement.
That might be true sometimes, but on other occasions the dream story comes first and triggers movements. A strong movement, especially one aimed at defending life and limb, breaks through the muscle inhibition of REM sleep and wakens the dreamer.
For example, I once dreamed that somebody threw a baseball straight at my face. I awakened myself by jerking my arms upward as if to catch it.
This may explain the origins of the myth that "you cannot let yourself die during a dream, or you will really die." Students say that is untrue; many have died in dreams and lived to tell about it.
However, life-or-death situations in a dream might trigger strong self-defense movements, and those can break through the muscle suppression of REM sleep. Then the dreamer awakens.
Animals often show muscle activity during sleep. A student reported that after a day of hunting, her dogs had unusually active sleep.
After a day's hunt, I have often seen my dogs in the rapid eye movement state while sleeping. They will fall asleep, and I can observe every movement of their eyes. Since they are deerhounds, they often bark and act as though they are chasing a deer.
Their legs make quick jerking motions as though they are trying to run. They will start breathing very hard during this period. These dreams are sometimes very short, sometimes quite long.
This is good evidence that animals do dream and have rapid eye movement periods. These types of dreams probably result from their having been hunting. [Author's files]
One of the most intriguing types of dream is the lucid dream. This is a dream in which you realize you are dreaming.
If you realize you have "gone lucid" in a dream (i.e. you suddenly realize, during the dream, that it must be a dream) you can stay calm, avoid waking yourself up, and let the dream continue.
In that case, you can experiment with the dream or intervene in the activity of the dream, and these experiences are often easily remembered later. For most people, lucid dreams are rare. For others, they are commonplace.
What is a lucid dream?
A classic report of a lucid dream comes from van Eeden (1913, in Tart, 1973):
On September 9, 1904, I dreamed that I stood at a table before a window. On the table were different objects. I was perfectly well aware that I was dreaming and I considered what sorts of experiments I could make.
I began by trying to break glass, by beating it with a stone. I put a small tablet of glass on two stones and struck it with another stone. Yet it would not break.
Then I took a fine claret-glass from the table and struck it with my fist, with all my might, at the same time reflecting on how dangerous it would be to do this in waking life; yet the glass remained whole. But lo! When I looked at it again after some time, it was broken.
It broke all right, but a little too late, like an actor who misses his cue. This gave me a very curious impression of being in a fake-world, cleverly imitated, but with small failures.
I took the broken glass and threw it out of the window, in order to observe whether I could hear the tinkling. I heard the noise all right and I even saw two dogs run away from it quite naturally.
I thought what a good imitation this comedy-world was. Then I saw a decanter with claret and tasted it, and noted with perfect clearness of mind: "Well, we can also have voluntary impressions of taste in this dream-world; this has quite the taste of wine." (p.47)
Students report that lucid dreams often end with a surge of self-consciousness. The dreamer becomes increasingly self-conscious and wakes up. Alternatively, the dream proceeds onward and the dreamer ceases to be lucid.
My favorite lucid dream occurred when I was lecturing to a class of students. This was a familiar scenario because I did it for 30 years, but in this case I suddenly realized it was a dream. I informed the class of this fact.
As class ended and the students filed out, I asked if they found it objectionable that I had told them it was "just a dream." They said they did not; in fact, they seemed amused.
Lucid dreams can be cultivated, according to Stephen LaBerge (1980). He developed a technique that included self-instructions such as, "Next time I'm dreaming, I want to remember I'm dreaming."
LaBerge completed a dissertation at Stanford about lucid dreaming. Then he made a career out of discussing and promoting lucid dreaming by founding The Lucidity Institute.
A small number of dreams seem to contain important insights about emotional or psychological problems. Here are some common categories of meaningful dreams, each with two examples provided by students.
1. Warning dreams point to dangerous situations in the future.
(A student dreams about his drunk-driving friends dying in a wreck. Another student dreams about the ill consequences of dropping out of school.)
2. Guilt and worry dreams express concern about past or present events.
(A student is "haunted" by dreams of her grandfather, whose last wishes concerning burial were not carried out. A young man dreams that another man fathered his wife's new baby.)
3. Inspirational dreams set goals or ideals to attain.
(A tennis-playing student, ranked at the state level, has a recurring dream of beating a famous star in a tournament match. A student having trouble in school dreams of rising to the occasion at the end of the term, doing well on his exams. Inspired by the dream, he makes it come true.)
4. Post-traumatic dreams contain flashbacks to stressful events.
(One girl relives a serious traffic accident in recurrent dreams. Another dreams of her near-
5. Problem-solving dreams present solutions to difficulties.
(A boy dreams of sticking little numbered labels to wires, which allows him to figure out how to wire his car stereo. A girl loses her bracelet then remembers, in a dream, where she put it.)
6. Death-reconciliation dreams help people deal with death of loved ones.
(A boy dreams that his father comes back to life to catch up on the news of his life. A girl dreams her recently killed boyfriend returns and gives her the chance to say she loves him.)
What are some categories of meaningful dreams?
Some hard-nosed psychologists scoff at the idea of meaningful dreams. It is true a lot of dream interpretation advice is useless junk. Dream-symbol dictionaries are generally useless. So are web sites offering interpretations of specific symbols and themes.
Dream symbolism tends to be more personal than that. Dreams reflect the full diversity of individual memories, feelings, and personalities. Some dreams definitely carry powerful warnings or inspirations, but when they do, it is usually obvious to the dreamer.
Blakeslee, S. (1988, August 11). Researchers report new advances in understanding the dream state. New York Times, p.Y23.
Goleman, D. & Engel, J. (1976, November) A feeling of falling. Psychology Today, pp.107-108.
LaBerge, S. (1980, January). Lucid dreaming: Directing the action as it happens. Psychology Today, pp.48-57.
Lincoln, J. S. (1935) The Dream in Primitive Cultures. London: Cresset Press.
Robert, G. & Zadra, A. (2014) Thematic and content analysis of idiopathic nightmares and bad dreams. Sleep, 37, 409-417. doi:10.5665/sleep.3426
Tart, C .C. (1973) States of consciousness. In L. Bourne & B. Ekstrand (Eds.), Human Action: An Introduction to Psychology. New York: Dryden Press, pp. 247-279.
Webb, W. (1981). Sleep Disorders and Modes of Treatment. Riverside, CA: Psychological Seminars, Inc.
Write to Dr. Dewey at email@example.com.