Five Fascinating Facts About Dreams
Dreaming is something everyone does, whether or not they are conscious of it. In fact, one may not be aware of how much work is happening in the brain while he or she lays comfortably in bed at night. According to Sleep.org, dreams are “stories, images, and sensations created by our mind while we sleep.” Yet, as common and natural as dreams are, they differ from everyday actions like talking, eating, and exercising in a multitude of ways.
1. The entire brain is active during dreaming.
Sleeping accounts for one quarter to one third of one’s life. Prior to the 1950s, people believed that sleep was a passive activity in which the brain was dormant; however, brain scans of sleeping individuals have shown quite the opposite. In fact, REM sleep is controlled by the reticular activating system, a network of neurons that runs from the brain stem through the thalamus, which regulates consciousness and alertness, to the cortex, the largest part of the brain associated with higher level processes like consciousness, emotion, language and memory.
While one is dreaming, the limbic system in the midbrain handles emotion and behavior. Within the limbic system is the amygdala, which modulates the fear response and is particularly active during REM sleep. In fact, in 2019, the Netherlands Institute for Neuroscience found that restful REM sleep is essential for processes distressing events. The study stated that, during sleep, 'memory traces' of experiences from the past day are spontaneously played back, like a movie. Among all remnants of the day, a specific memory trace can be activated by presenting the same odor as the one that was present during the experience while awake. Meanwhile, memory traces are adjusted during sleep: some connections between brain cells are strengthened, others are weakened. Restless REM sleep disturbs these nocturnal adjustments, which are essential for recovery and adaptation to distress.
The cortex is responsible for the content and imagery of one’s dreams, although its activity is low during REM sleep, which may account for some of the strange or illogical dreams one has.
2. The body is wired not to act out one’s dreams.
Most dreaming occurs during REM, or rapid eye movement, sleep. During REM sleep, activity levels in the brain are similar to waking levels, resulting in faster breathing, increased heart rate and blood pressure, and vivid dreams. The phenomenon known as REM atonia, the temporary paralysis of one’s voluntary muscles, such as arms and legs, prevents the individual from physically acting out one’s dreams.
3. People forget approximately 95% of their dreams.
Researchers have been studying dream recall, or the lack thereof, for decades. People typically have four to six dreams every night; they just do not recall many of these dreams. It is still unknown whether people who seldom remember their dreams actually dream less than those who frequently remember their dreams, or if they forget their dreams more easily. One theory to explain the phenomenon of dream amnesia is that the frontal lobes, which play a key role in memory formation, are less active during REM sleep.
A 2016 study published in the journal Behavioral and Brain Sciences discovered that a lack of dream recollection may be caused by changes in levels of neurotransmitters during REM sleep. Another theory is that the hippocampus, a structure responsible for learning and memory processes, is not fully active when one awakens, which could result in a dream being present in short-term memory but not yet able to move to long-term storage.
4. One can learn to control his or her dreams.
A lucid dream is when one is conscious that he or she is dreaming while still asleep. Lucid dreaming is thought to be a combination of consciousness and REM sleep, during which one can control the content of a dream. In the last two decades, psychophysiologist Dr. Stephen LaBerge has pioneered lucid dreaming research and techniques.
Lucid dreaming often occurs spontaneously, but its techniques train the mind to notice its consciousness, so one can maintain consciousness during REM sleep. According to Healthline, lucid dreaming can be initiated by keeping a dream journal or by using techniques such as the “wake back to bed (WBTB)” method, which instructs one to set an alarm for five hours after their bedtime, go to sleep, wake up to the alarm and stay up for thirty minutes to enjoy a quiet activity before falling back asleep. Lucid dreaming is more likely after one falls back to sleep, since the chances of lucid dreaming vary by the levels of alertness. The notion of waking up in the middle of the night is meant to heighten alertness that had dwindled while one was sleeping for the prior five hours.
5. There are a multitude of different theories explaining why people dream.
Among the more touted theories is the processing of information. The idea, first proposed by J. Allan Hobson and Robert McCarley, states that circuits in the brain become activated during REM sleep, triggering the amygdala and hippocampus to create an array of electrical impulses. This results in the compilation of random ideas, images, and memories that appear in dreams. One’s mind joins the different elements into a cohesive narrative when he or she wakes up. The emotional regulation dream theory states that dreams assist in processing and coping with emotions or traumatic events during sleep. It states that there is a strong link between the activity of the amygdala and hippocampus during dreaming and memory storage and emotional processing during intense dreams.Another notion to explain dreaming is to prepare and protect us from future occurrences. Examples of dreams that may play such a role include falling over a cliff, running away from a pursuer or forgetting to study for an exam; hence, why many dreams contain dramatic or unnerving content.
In short, although dreams may not always reflect reality, they still serve a variety of purported roles. Scientific research has progressed so much that people understand the functions of different parts of the brain while dreaming. Hopefully, in the near future, scientists can uncover more of the activity and mysteries surrounding them.
Blackmore, S. What Happens When We Dream? Science Focus. https://www.sciencefocus.com/the-human-body/what-happens-when-we-dream/
Cherry, K. (2021, February 11). Interesting Facts About Dreams. Verywell Mind. https://www.verywellmind.com/facts-about-dreams-27959
Netherlands Institute for Neuroscience - KNAW. (2019, July 11). REM sleep silences the siren of the brain: Restless REM sleep a risk for many mental disorders?. ScienceDaily. www.sciencedaily.com/releases/2019/07/190711141258.htm
Nunez, K. (2019, May 15). 5 Techniques to Try for Lucid Dreaming. Healthline. https://www.healthline.com/health/healthy-sleep/how-to-lucid-dream
Obringer, L. & Jeffcoat, Y. (2021, October 15). Dream Recall. How Stuff Works. https://science.howstuffworks.com/life/inside-the-mind/human-brain/dream4.htm
(2021, March 12). Dreams: What They Are and Why They Happen. Sleep. https://www.sleep.org/dreams/