Научная электронная библиотека
Монографии, изданные в издательстве Российской Академии Естествознания
Why Do We Dream?– Top Dream Theories
“Dreams are the touchstones of our characters”. – Henry David Thoreau
Dreams have fascinated philosophers for thousands of years, but only recently have dreams been subjected to empirical research and concentrated scientific study. Chances are that you’ve often found yourself puzzling over the mysterious content of a dream, or perhaps you’ve wondered why you dream at all.
First, let’s start by answering a basic question – What is a dream? A dream can include any of the images, thoughts and emotions that are experienced during sleep. Dreams can be extraordinarily vivid or very vague; filled with joyful emotions or frightening imagery; focused and understandable or unclear and confusing.
Why do we dream? What purpose do dreams serve? While many theories have been proposed, no single consensus has emerged. Considering the enormous amount of time we spend in a dreaming state, the fact that researchers do not yet understand the purpose of dreams may seem baffling. However, it is important to consider that science is still unraveling the exact purpose and function of sleep itself.
Some researchers suggest that dreams serve no real purpose, while others believe that dreaming is essential to mental, emotional and physical well-being. Ernest Hoffman, director of the Sleep Disorders Center at Newton Wellesley Hospital in Boston, Mass., suggests that “...a possible (though certainly not proven) function of a dream to be weaving new material into the memory system in a way that both reduces emotional arousal and is adaptive in helping us cope with further trauma or stressful events”.
While dreams can vary considerably, sleep researcher J. Allan Hobson (1988) identified five basic characteristics of dreams:
1. Dreams Often Feature Intense Emotions
One of the major characteristics of dreams is that the emotions experienced in dreams can be intense, painful and acute. People commonly report dreaming about deeply embarrassing situations (i.e. being nude in public) or profoundly terrifying events (i.e. being chased by an attacker). In some instances, these emotions can become so intense that they interrupt the dream or cause the dreamer to wake abruptly. The three most common emotions that become intensified by dreams are anxiety, fear and surprise.
2. Dreams Are Frequently Disorganized and Illogical
Dreams are full of discontinuities, ambiguities and inconsistency, but sometimes these things can lead to downright bizarre dream content. According to Hobson, one of the hallmarks of dreams is “illogical content and organization, in which the unities of time, place and person do not apply, and natural laws are disobeyed”. Some examples of illogical dream content includes flying, time travel, talking animals, sudden transformations of both people and objects and sudden shifts in setting.
3. Strange Dream Content Is Accepted Without Question
The odd events and content that occur in dreams are typically accepted without question by the dreaming mind. According to Hobson, the unquestioning acceptance of dream content is due to the strength of our internally generated emotions and perceptions. Within the dream, these strange and illogical events, perceptions and objects are not seen as being out of place. If the dream is remembered upon waking, the content of the dream is seen as odd or even difficult to explain.
4. People Often Experience Bizarre Sensations
Strange sensory experiences are another cardinal characteristic of dreams. The sensation of falling, an inability to move quickly and being unable to control body movements are just a few of the commonly reported sensory experiences that occur during dreams.
5. Dreams Are Difficult to Remember
While memory seems to be intensified within the context of the dream, access to the information contained within the dream diminishes rapidly once the dreamer wakes. Dream researchers estimate that approximately 95 % of all dreams are forgotten entirely upon awakening.
Understanding the Characteristics of Dreams
While many people may familiar with these five common characteristics of dreams, some may be unaware of just how common these experiences are. “Dream characteristics and dream object may be of an everyday nature or altogether fantastic and impossible collages of existing reality; they may behave normally or indulge in the most absurd, improbable or impossible actions in settings either familiar or bearing only the faintest resemblances to those of real life”, Hobson explains.
Psychoanalytic Theory of Dreams:
Consistent with the psychoanalytic perspective, Sigmund Freud’s theory of dreams suggested that dreams were a representation of unconscious desires, thoughts and motivations. According to Freud’s psychoanalytic view of personality, people are driven by aggressive and sexual instincts that are repressed from conscious awareness. While these thoughts are not consciously expressed, Freud suggested that they find their way into our awareness via dreams.
In his famous book The Interpretation of Dreams, Freud wrote that dreams are “...disguised fulfillments of repressed wishes”. He also described two different components of dreams: manifest content and latent content. Manifest content is made up of the actual images, thoughts and content contained within the dream, while the latent content represents the hidden psychological meaning of the dream.
Freud’s theory contributed to the popularity of dream interpretation, which remains popular today. However, research has failed to demonstrate that the manifest content disguises the real psychological significance of a dream.
Activation- Synthesis Model of Dreaming:
The activation-synthesis model of dreaming was first proposed by J. Allan Hobson and Robert McClarley in 1977. According to this theory, circuits in the brain become activated during sleep, which causes areas of the limbic system involved in emotions, sensations and memories, including the amygdala and hippocampus, to become active. The brain synthesizes and interprets this internal activity and attempts to find meaning in these signals, which results in dreaming. This model suggests that dreams are a subjective interpretation of signals generated by the brain during sleep.
While this theory suggests that dreams are the result of internally generated signals, Hobson does not believe that dreams are meaningless. Instead, he suggests that dreaming is “…our most creative conscious state, one in which the chaotic, spontaneous recombination of cognitive elements produces novel configurations of information: new ideas. While many or even most of these ideas may be nonsensical, if even a few of its fanciful products are truly useful, our dream time will not have been wasted”.
Other Theories of Dreams:
Many other theories have been suggested to account for the occurrence and meaning of dreams. The following are just of few of the proposed ideas:
- One theory suggests that dreams are the result of our brains trying to interpret external stimuli during sleep. For example, the sound of the radio may be incorporated into the content of a dream.
- Another theory uses a computer metaphor to account for dreams. According to this theory, dreams serve to ‘clean up’ clutter from the mind, much like clean-up operations in a computer, refreshing the mind to prepare for the next day.
- Yet another model proposes that dreams function as a form of psychotherapy. In this theory, the dreamer is able to make connections between different thoughts and emotions in a safe environment.
- A contemporary model of dreaming combines some elements of various theories. The activation of the brain creates loose connections between thoughts and ideas, which are then guided by the emotions of the dreamer.
Stages of Sleep
The invention of the electroencephalograph allowed scientists to study sleep in ways that were not previously possible. During the 1950s, a graduate student named Eugene Aserinsky used this tool to discover what is known today as REM sleep. Further studies of human sleep have demonstrated that sleep progresses through a series of stages in which different brain wave patterns are displayed.
There are two main types of sleep:
1. Non-Rapid Eye Movement (NREM) Sleep (also known as quiet sleep)
2. Rapid Eye Movement (REM) Sleep (also known as active sleep or paradoxical sleep)
The Beginnings of Sleep
During the earliest phases of sleep, you are still relatively awake and alert. The brain produces what are known as beta waves, which are small and fast. As the brain begins to relax and slow down, slower waves known as alpha waves are produced. During this time when you are not quite asleep, you may experience strange and extremely vivid sensations known as hypnagogic hallucinations. Common examples of this phenomenon include feeling like you are falling or hearing someone call your name.
Another very common event during this period is known as a myoclonic jerk. If you’ve ever startled suddenly for seemingly no reason at all, then you have experienced this odd phenomenon. While it may seem unusual, these myoclonic jerks are actually quite common.
Stage 1
Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5–10 minutes). If you awaken someone during this stage, they might report that they weren’t really asleep.
Stage 2
Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow.
Stage 3
Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep.
Stage 4
Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep.
Stage 5
Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs because of increased brain activity, but voluntary muscles become paralyzed.
The Sequence of Sleep Stages
It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night.
On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. REM sleep can last up to an hour as sleep progresses.
Top Reasons to Get a Good Night’s Sleep
How Sleep Improves Memory, Reduces Stress and Enhances Decision-Making
When was the last time you found yourself drifting off in the middle of a long class lecture or meeting? According to the National Sleep Foundation’s 2008 “Sleep in America” poll, 29 % of participants reported becoming very sleepy or even falling asleep at work in the previous month alone.
Recent research has linked lack of sleep to a wide range of ailments, including memory problems and obesity. Learn more about some of the top reasons why you should get a good night’s sleep.
Sleep May Help You Learn More Effectively
Researchers have long believed that sleep plays an important role in memory, but recent evidence suggests that getting a good night’s sleep can improve learning. In one study, researchers found that depriving students of sleep after learning a new skill significantly decreased memory of that skill up to three days later. Known as the memory consolidation theory of sleep, this notion proposes that sleep serves to process and retain information learned earlier while awake. While there is research both for and against the theory, many studies have shown that sleep can play an important role in certain types of memory.
Research Suggests Sleep Deprivation May Contribute to Obesity
In addition to affecting memory and learning, lack of sleep has been linked to body weight. In one 2005 study published in the Archives of Internal Medicine, overweight participants were found to sleep less than participants of a normal weight. Brandon Peters, About.com’s Guide to Sleep Disorders, reports that poor sleep at age 30 months can predict obesity at age seven. While researchers do not yet understand exactly how sleep disruption impacts appetite and metabolism, getting a good night’s sleep certainly can’t hurt your weight loss or weight maintenance efforts.
Sleep is Important for Managing Stress
According to many experts, most people need between seven and eight hours of sleep each night. What happens when you don’t get enough sleep? Symptoms such as moodiness, anxiety, aggression and increased stress levels can
result. About.com’s Guide to Stress Management, Elizabeth Scott, suggests taking “power naps” to combat drowsiness, reduce stress and increase productivity. While sleeping more certainly won’t eliminate all stress, it can help increase your readiness to cope with the stress of day-to-day life.
Sleep Can Help You Make Better Decisions
Have you ever found yourself struggling to make relatively simple decisions after a night of poor sleep? In addition to reducing such things as response time and accuracy, lack of sleep has also been linked to difficulty making good decisions. In one study published in the journal Sleep, researchers found that sleepiness has a serious impact on the ability to make effective decisions. Another study suggested that sleep impairs decision-making when gambling by increasing expectations of potential gains while minimizing losses. If you’re facing a challenging decision, make sure that you are well rested so that you will be at your best.