Dreams Through the Research: REM Sleep, the History of Dream Interpretation, Lucid Dreams and Out-of-Body Experiences, Nightmare Treatment and Conception Dreams

When and why do we dream?

In 1953, Aserinsky and Kleitman discovered stretches of sleep in which the eyes move rapidly. People woken during this REM sleep usually remembered vivid dreams. We now know dreaming also happens outside REM sleep, but vivid, story-like dreams are more common in REM.

There are several theories about why we dream, and none has won out yet.

• Wish fulfilment (Freud, 1900): The Interpretation of Dreams treated dreams as repressed wishes in disguise. Its cultural influence was enormous, but the theory is hard to test scientifically.
• Activation-synthesis hypothesis (Hobson & McCarley, 1977): dreams are the cortex weaving a story out of signals from the brainstem during REM sleep.
• Threat simulation theory (Revonsuo, 2000): an evolutionary account in which dreams let us rehearse dangerous situations.

What do flying and falling dreams mean?

When Nielsen et al. (2003) asked 1,181 Canadian university students about 55 “typical dreams,” being chased (81.5%) and falling (73.8%) were among the most common, and about half (48.3%) had dreamed of flying.

Being this common suggests such dreams are less special prophecies than reflections of worries and bodily sensations that many people share. One-to-one interpretation charts such as “falling dreams foretell failure” have no evidence behind them. When reflecting on a dream, linking the emotion you felt to your current concerns is more useful than a symbol’s dictionary meaning. OIYO’s dream dictionary shows traditional and psychological readings side by side.

Lucid dreams: knowing you’re dreaming inside the dream

A lucid dream is one in which you know “this is a dream” while dreaming. LaBerge et al. (1981) had lucid dreamers move their eyes in a pre-agreed pattern inside the dream, confirming in the lab that lucidity happens during genuine REM sleep. In 2021, an experiment even reported simple two-way question-and-answer exchanges with people in lucid dreams (Konkoly et al., 2021).

Induction methods include reality testing — checking “am I dreaming?” during the day — and MILD, where you repeat “I will notice I’m dreaming” before sleep. A review found some evidence that they work, but success rates vary widely and study quality is still low (Stumbrys et al., 2012). Be careful with methods that repeatedly interrupt sleep, as they can harm sleep quality.

Out-of-body experiences: the feeling of leaving the body is made by the brain

“Astral projection” — consciousness leaving the body to travel to other dimensions — is often presented alongside lucid dreaming. The feeling of seeing yourself from outside your body is a genuinely reported experience, especially common during sleep paralysis or at the edges of falling asleep and waking.

Blanke et al. (2002) reported that electrically stimulating the temporoparietal junction during brain surgery gave a patient the feeling of seeing herself from outside her body. The leading explanation is that the experience arises as the brain integrates information about the body’s position; there is no evidence that consciousness actually leaves the body.

Nightmares: there are ways to reduce them

If frequent nightmares make you dread going to sleep, imagery rehearsal therapy (IRT) can help. While awake, you rewrite the recurring nightmare with a less frightening ending and rehearse the new version in your mind for a few minutes each day.

In a randomised trial by Krakow et al. (2001), people who received IRT had far fewer nightmares and slept better. The American Academy of Sleep Medicine also recommends IRT for nightmare disorder (Morgenthaler et al., 2018). For trauma-related nightmares, it is best done with a professional.

Conception dreams and dream reading as culture

In Korea there is a custom of families sharing taemong — dreams said to announce a pregnancy. Traditional readings say dragon or tiger dreams mean a boy, and flower or fruit dreams a girl. These stories have meaning as a cultural ritual for sharing the anticipation of a new family member. But there is no scientific evidence that dreams reveal a child’s sex or future.

Summary at a glance

Topic	What research says	What’s exaggerated
Why we dream	Linked to REM sleep; several theories	”Every dream is a code hiding one meaning”
Typical dreams	Being chased, falling and flying are very common	One-to-one interpretation charts
Lucid dreams	Verified in the lab; induction results vary	”Anyone can easily control their dreams”
Out-of-body experiences	A feeling generated by the brain	”Consciousness really leaves the body”
Nightmares	IRT can reduce them	—
Conception dreams	Meaningful as family culture	Predicting sex or the future

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References

• Aserinsky, E., & Kleitman, N. (1953). Regularly occurring periods of eye motility, and concomitant phenomena, during sleep. Science, 118(3062), 273–274.
• Freud, S. (1900). Die Traumdeutung (The Interpretation of Dreams). Franz Deuticke.
• Hobson, J. A., & McCarley, R. W. (1977). The brain as a dream state generator: An activation-synthesis hypothesis of the dream process. American Journal of Psychiatry, 134(12), 1335–1348.
• Revonsuo, A. (2000). The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23(6), 877–901.
• Nielsen, T. A., et al. (2003). The typical dreams of Canadian university students. Dreaming, 13(4), 211–235.
• LaBerge, S., Nagel, L. E., Dement, W. C., & Zarcone, V. P. (1981). Lucid dreaming verified by volitional communication during REM sleep. Perceptual and Motor Skills, 52(3), 727–732.
• Konkoly, K. R., et al. (2021). Real-time dialogue between experimenters and dreamers during REM sleep. Current Biology, 31(7), 1417–1427.
• Stumbrys, T., Erlacher, D., Schädlich, M., & Schredl, M. (2012). Induction of lucid dreams: A systematic review of evidence. Consciousness and Cognition, 21(3), 1456–1475.
• Blanke, O., Ortigue, S., Landis, T., & Seeck, M. (2002). Stimulating illusory own-body perceptions. Nature, 419(6904), 269–270.
• Krakow, B., et al. (2001). Imagery rehearsal therapy for chronic nightmares in sexual assault survivors with posttraumatic stress disorder. JAMA, 286(5), 537–545.
• Morgenthaler, T. I., et al. (2018). Position paper for the treatment of nightmare disorder in adults. Journal of Clinical Sleep Medicine, 14(6), 1041–1055.