Summary

Dreams are images, thoughts and feeling experienced while asleep, particularly strongly associated with rapid eye movement sleep. The contents and purpose of dreams are not fully understood, though they have been a topic of speculation and interest throughout recorded history.

Stages of Sleep

When the body decides that it is time to sleep, neurons near the eyes start to send signals throughout the body. According to experts, these neurons are located in such close proximity to neurons that control eyelid muscles that the eyelids begin to grow heavy. Glands begin to secrete a hormone that helps induce sleep and neurons send signals to the spinal cord, which makes the body relax.

Emotions

The most common emotion experienced in dreams is anxiety. Negative emotions are more common than positive feelings. The U.S. ranks the highest amongst industrialized nations for aggression in dreams with 50% of U.S. males reporting aggression in dreams, compared to 32% for Dutch men.

Sexual Content

Various studies show that sexual dreams occur no more than 10% of the time and are more prevalent in the early to mid teens. Another study showed that 8% of men's and women's dreams have sexual content. In some cases, sexual dreams may result in orgasm or nocturnal emission. These are commonly known as wet dreams.  

Recurring Dreams

While the content of most dreams is dreamt only once, many people experience recurring dreams - that is, the same dream narrative is experienced over different occasions of sleep. Up to 70% of females and 65% of males report recurrent dreams.

Common Themes

Content-analysis studies have identified common reported themes in dreams. These include: situations relating to school, being chased, running slowly in place, sexual experiences, falling, arriving too late, a person now alive being dead, teeth falling out, flying, embarrassing moments, failing an examination, or a car accident. 12% of people only dream in black and white.   

Disease Associated Differences

There is evidence that certain diseases (normally only neurological diseases) can impact dreams. For instance, people with synesthesia have never reported black and white dreaming, and often have a difficult time imagining the idea of dreaming in black and white only.

Recalling Dreams

The recall of dreams is extremely unreliable, though it is a skill that can be trained. Dreams that are difficult to recall may be characterized by relatively little effect, and factors such as salience, arousal, and interference play a role in dream recall. A dream journal can be used to assist dream recall, for psychotherapy or entertainment purposes.

Deja Vu

The theory of deja vu dealing with dreams indicates that the feeling of having previously seen or experienced something could be attributed to having dreamt about a similar situation or place, and forgetting about it until one seems to be mysteriously reminded of the situation while awake.  

Dreams and REM Sleep

The most current ideas on REM sleep are associated with learning. Researchers are trying to determine the effects that REM sleep and the lack of REM sleep have on learning certain types of skills (usually physical skills rather than rote memory). This connection seems strong in some respects due to the fact that infants and toddlers experience much more REM sleep than adults. 

Dream Facts

• Most dreams last anywhere from 5 to 20 minutes

• People don't only dream in black and white, as was once believed

• Even though they may not remember them, everyone dreams several times a night. In fact, during a typical lifetime, we spend about 6 years dreaming

• People who have been blind from birth have dreams that are formed from their other senses (e.g. touch, smell, sound)

• When people are snoring, they are not dreaming

Night Terrors

Nightmares occur during REM sleep, but night terrors occur during non-REM sleep, usually in the first cycle of the deepest phase of sleep (within the first hour or two of going to bed). Night terrors can last anywhere from 5 to 20 minutes. People having a night terror are still asleep but may look like they are awake. For example, they may sit up in bed screaming with their eyes wide open. When they actually do wake up, they usually have no memory of the episode (although some people do remember them). Night terrors occur most frequently in children, but adults can also experience them.

More Information

Dream Library: www.dreamgate.com

The Dreams Foundation:  www.dreams.ca

National Sleep Foundation:  www.sleepfoundation.org

The Lucidity Institute: www.lucidity.com     

International Association for the Study of Dreams:  www.asdreams.org

Source: SleepWeb (Marketdata Enterprises, Inc.) research