Just like Beyonce’s song, a night of sleep can end up as a “Sweet Dream or a Beautiful Nightmare,” well, in my experience nightmares are not beautiful, but she's the uber-famous recording artist, so I'll let it slide . But the real question is what causes us to have a sweet dream or a nightmare?
There are two types of sleep that we experience, Non-Rapid Eye Movement sleep (NREM) and Rapid-Eye Movement sleep (REM).
REM sleep is the time that we experience our most vivid dreams, 75% of sleep occurs NREM. Dreams during NREM sleep are very rare, muscles are not paralyzed and there is minimal eye movement. NREM is divided into 3 stages, each with distinctive brain wave patterns.
Stage 1 of NREM sleep is the beginning of sleep, the eyes are moving slowly, brain monitors show that alpha waves disappear and theta waves appear. In stage 1, sleepers often experience a hypnic jerk, which is an involuntary muscle twitch, resembling a “jump” made when a person is startled, a sensation of falling often occurs with a hypnic jerk. This happens to me all the time, I lay down and then see myself running in a field, only to fall in a whole and wake up “jumping” or trying to catch myself and break my fall.
Stage 2 of NREM sleep, there is no eye movement and the sleeper is a very light sleep. Stage 3 is characterized as a very deep sleep, known as slow-wave sleep. Dreaming is common in this stage, but not nearly as common as in REM sleep. Dreams in this stage tend to be less memorable and typically are not remembered as they are in REM sleep. Stage 3 is the stage that many people with sleeping disorders, such as sleep walking are in when they sleep walk.
To start, a dream or nightmare occurs during the REM or Rapid Eye Movement sleep, you guessed it, at this point in sleep, and the eyes are rapidly moving. This comprises roughly 20-25% of an adult’s sleep each night. During REM sleep, the activity of the brain is very similar to that when a person is awake, but the body is paralyzed, due to the relaxed state of the skeletal muscles at this time, because motor neurons are not being stimulated.
Types of dreams
When we are asleep, there are a number of different types of dreams that we can have. They include dreams, lucid dreams and nightmares. Dreams are classified as a grouping of images, thoughts, sounds and emotions that the mind experiences.
Lucid dreams are the type of dreams in which we are aware that we are dreaming, so we can actively participate in and change the events and locations that happen in the dream, how aware we are during the dream determines how realistic it is.
We’ve all probably had at least one nightmare in our lives, but for any of those lucky few who haven’t, a nightmare is typically classified as a dream that triggers a strong negative effect from the sleeper, such as fear. Nightmares typically contain situations of discomfort, pain, danger, psychological or physical distress. Often times a sleeper will wake up from the nightmare in a distressed state and may be unable to go back to sleep.
It is interesting to look at how nightmares are perceived by different cultures. Some cultures believe that nightmares are a sign that the dreamer is open to physical and spiritual harm, while in other cultures they are thought to contain messages from the spirits that can predict the future. To me though, Nightmares=Not fun.
Nightmares can have a number of causes both physical and emotional. Some physical causes are sleeping in uncomfortable positions, fever and eating too close to bedtime (this increases the body’s metabolism and brain activity, potentially triggering nightmares). Some emotional triggers of nightmares include depression, stress, anxiety, experiencing a traumatic incident, such as rape and post-traumatic stress disorder.1
The typical protocol for the treatment of reoccurring nightmares is to treat the underlying problem, or believed cause of the nightmare. Using this hypothesis for treatment, treating the cause/trigger, the nightmares should fade away.
For nightmares that persist after treating the believed underlying cause, a treatment known as Imagery Rehearsal Therapy can be used. In this type of treatment a person, while awake writes down or describes their nightmare, and then while still awake writes an alternate ending to the nightmare, so that it does not upset them. The person is then instructed to visualize and continually replay this rewritten nightmare (now a new dream) in their minds.
A study published in 2000 involved nearly 200 women who had been victims of sexual assault, who were plagued by nightmares. They were divided into two groups, one group which maintained their regular sleep routine, while the other group was given Imagery Rehearsal Therapy. At the end of treatment, the women in the Imagery Rehearsal Therapy group had a significant decrease in nightmares and disturbing dreams. 2
So the next time that you lay your head down to sleep, try your best to think happy thoughts and hopefully you will have a Sweet Dream or a Beautiful Nightmare.
Check out Rhytmn City's (a dance crew from the fourth season of ABDC) take on a Sweet Dream or a Beautiful Nightmare...
1Forbes, D. et al. (2001) Brief Report: Treatment of Combat-Related Nightmares Using Imagery Rehearsal: A Pilot Study, Journal of Traumatic Stress 14 (2): 433-442
2Johnston L, Krakow B, Melendrez D, Herlan M, Hollifield M, Chavez-Kennedy D. 2000. Treatment of nightmares and insomnia in crime victims. Sleep 23 (Suppl #2): A316.