Sleeping And Dreaming
Despite the large amount of time we spend asleep, surprisingly little is actually known about sleeping and dreaming. Much has been imagined, however. Over history, sleep has been conceived as the space of the soul, as a state of absence akin to death, as a virtual or alternate reality, and more recently, as a form of (sub)consciousness in which memories are built and erased. The significance attributed to dreams has varied widely as well. The Ancient Greeks had surprise dream encounters with their gods. Native Americans turned to their dreams for guidance in life. Shamans dreamed in order to gather information from the spirits.
Sleep and dreams have defined eras, cultures, and individuals. Sigmund Freud’s interpretation of dreams revolutionized twentieth-century thought. Historical archives record famous short sleepers and notable insomniacssome accounts reliable, some not. When Benjamin Franklin counseled, “Early to bed, early to rise, makes a man healthy, wealthy, and wise,” he was using sleep habits to symbolize his pragmatism.
Important public policy issues have arisen in our modern 24-hour society, where it is crucial to weigh the value of sleep versus wakefulness. Scientific knowledge about sleep is currently insufficient to resolve the political and academic debates raging about how much and when people should sleep. These issues affect almost everybody, from the shift worker to the international traveler, from the physician to the policy maker, from the anthropologist to the student preparing for an exam.
In 2004-2005, the Penn Humanities Forum will focus on the topic of “Sleep and Dreams.” Proposals are invited from researchers in all humanistic fields concerned with representations of sleep, metaphors used to describe sleep, and sleep as a metaphor in itself. In addition, we solicit applications from those who study dreams, visions, and nightmares in art or in life, and the approaches taken to their interpretation.
We also welcome proposals about the effects of dreaming on the dreamer, and the resulting emotions, behaviors, and actions taken or foregone in response to dreams.
In this Forum on Sleep and Dreams, we will see how the diversity of academic disciplines can help to answer important questions about sleep and dreamingquestions that may touch the basis of human intellect. The Forum is fortunate in having an expert on the psychophysiology of sleep and dreaming, Hans Van Dongen, as the Topic Director for 2004-2005. His knowledge of advances in biomedical sleep research (which is vibrant at Penn) will complement the Mellon Fellows’ cultural and historical perspectives on the subject arising from books, paintings, sculptures, movies, music, and other forms of culture.
According to Professor Van Dongen, the functions of sleep and dreams are still largely unclear to scientists. Whereas artists and humanists have long been concerned with sleep and dream states, the sciences mostly ignored it until the discovery was made that there is brain activity during sleep. It has now been documented that sleep is a necessity for health, for well-being, for the ability to think clearlythat is, for the overall quality of wakefulness. While much is known about the neurobiological underpinnings of sleep and dreams, however, the reasons behind these processes are still a mystery, and the question “what are sleeping and dreaming for?” awaits definitive answers. Under the circumstances, humanists have much to offer, not only to each other but to science as well, for the understanding of this fundamental aspect of life.
Myths and Facts about sleeping :
1. Snoring is a common problem, especially among men, but it isn’t harmful.
Although snoring may be harmless for most people, it can be a symptom of a life threatening sleep disorder called sleep apnea, especially if it is accompanied by severe daytime sleepiness. Sleep apnea is characterized by pauses in breathing that prevent air from flowing into or out of a sleeping person’s airways. People with sleep apnea awaken frequently during the night gasping for breath. The breathing pauses reduce blood oxygen levels, can strain the heart and cardiovascular system, and increase the risk of cardiovascular disease. Snoring on a frequent or regular basis has been directly associated with hypertension. Obesity and a large neck can contribute to sleep apnea. Sleep apnea can be treated; men and women who snore loudly, especially if pauses in the snoring are noted, should consult a physician.
2. You can “cheat” on the amount of sleep you get.
Sleep experts say most adults need between seven and nine hours of sleep each night for optimum performance, health and safety. When we don’t get adequate sleep, we accumulate a sleep debt that can be difficult to “pay back” if it becomes too big. The resulting sleep deprivation has been linked to health problems such as obesity and high blood pressure, negative mood and behavior, decreased productivity, and safety issues in the home, on the job, and on the road.
3. Turning up the radio, opening the window, or turning on the air conditioner are effective ways to stay awake when driving.
These “aids” are ineffective and can be dangerous to the person who is driving while feeling drowsy or sleepy. If you’re feeling tired while driving, the best thing to do is to pull off the road in a safe rest area and take a nap for 15-45 minutes. Caffeinated beverages can help overcome drowsiness for a short period of time. However, it takes about 30 minutes before the effects are felt. The best prevention for drowsy driving is a good night’s sleep the night before your trip.
4. Teens who fall asleep in class have bad habits and/or are lazy.
According to sleep experts, teens need at least 8.5 – 9.25 hours of sleep each night, compared to an average of seven to nine hours each night for most adults. Their internal biological clocks also keep them awake later in the evening and keep them sleeping later in the morning. However, many schools begin classes early in the morning, when a teenager’s body wants to be asleep. As a result, many teens come to school too sleepy to learn, through no fault of their own.
5. Insomnia is characterized by difficulty falling asleep.
Difficulty falling asleep is but one of four symptoms generally associated with insomnia. The others include waking up too early and not being able to fall back asleep, frequent awakenings, and waking up feeling unrefreshed. Insomnia can be a symptom of a sleep disorder or other medical or psychological/psychiatric problem, and can often be treated. According to the National Sleep Foundation’s 2002 Sleep in America poll, 58 percent of adults in this country reported at least one symptom of insomnia in the past year. When insomnia symptoms occur more than a few times a week and impact a person’s daytime functions, the symptoms should be discussed with a doctor or other health care provider.
6. Daytime sleepiness always means a person isn’t getting enough sleep.
Excessive daytime sleepiness is a condition in which an individual feels very drowsy during the day and has an urge to fall asleep when he/she should be fully alert and awake. The condition, which can occur even after getting enough nighttime sleep, can be a sign of an underlying medical condition or sleep disorder such as narcolepsy or sleep apnea. These problems can often be treated, and symptoms should be discussed with a physician. Daytime sleepiness can be dangerous and puts a person at risk for drowsy driving, injury, and illness and can impair mental abilities, emotions, and performance.
7. Health problems such as obesity, diabetes, hypertension, and depression are unrelated to the amount and quality of a person’s sleep.
Studies have found a relationship between the quantity and quality of one’s sleep and many health problems. For example, insufficient sleep affects growth hormone secretion that is linked to obesity; as the amount of hormone secretion decreases, the chance for weight gain increases. Blood pressure usually falls during the sleep cycle, however, interrupted sleep can adversely affect this normal decline, leading to hypertension and cardiovascular problems. Research has also shown that insufficient sleep impairs the body’s ability to use insulin, which can lead to the onset of diabetes. More and more scientific studies are showing correlations between poor and insufficient sleep and disease.
8. The older you get, the fewer hours of sleep you need.
Sleep experts recommend a range of seven to nine hours of sleep for the average adult. While sleep patterns change as we age, the amount of sleep we need generally does not. Older people may wake more frequently through the night and may actually get less nighttime sleep, but their sleep need is no less than younger adults. Because they may sleep less during the night, older people tend to sleep more during the day. Naps planned as part of a regular daily routine can be useful in promoting wakefulness after the person awakens.
9. During sleep, your brain rests.
The body rests during sleep, however, the brain remains active, gets “recharged,” and still controls many body functions including breathing. When we sleep, we typically drift between two sleep states, REM (rapid eye movement) and non-REM, in 90-minute cycles. Non-REM sleep has four stages with distinct features, ranging from stage one drowsiness, when one can be easily awakened, to “deep sleep” stages three and four, when awakenings are more difficult and where the most positive and restorative effects of sleep occur. However, even in the deepest non-REM sleep, our minds can still process information. REM sleep is an active sleep where dreams occur, breathing and heart rate increase and become irregular, muscles relax and eyes move back and forth under the eyelids.
10. If you wake up in the middle of the night, it is best to lie in bed, count sheep, or toss and turn until you eventually fall back asleep.
Waking up in the middle of the night and not being able to go back to sleep is a symptom of insomnia. Relaxing imagery or thoughts may help to induce sleep more than counting sheep, which some research suggests may be more distracting than relaxing. Whichever technique is used, most experts agree that if you do not fall back asleep within 15-20 minutes, you should get out of bed, go to another room and engage in a relaxing activity such as listening to music or reading. Return to bed when you feel sleepy. Avoid watching the clock.
Dreaming and The Stages of Sleeping.
One sleep cycle comprises of four stages and last for about 90-120 minutes. Dreams can occur in any of the four stages of sleep but the most vivid and memorable dreams occur in the last stage of sleep (also commonly referred to as REM sleep). The sleep cycle repeats itself about an average of four to five times per night, but may repeat as many as seven times. Thus, you can see how a person can have several different dreams in one night. Most people, however, only remember dreams that occur closer toward the morning when they are about to get up. But just because you can’t remember those dreams does not mean that
they never happened. Some people swear on the fact that they simply do not dream when in reality, they just don’t remember their dreams.
The Stages Of Sleep
Some text lists four stages of sleep, while others say there are five stages. Some consider the first five-ten minutes when you are falling asleep as a stage in the sleep cycle. We think that it is more of a transitional phase. While the other stages of sleep repeat themselves throughout the night, this phase of sleep does not. For this reason, we have excluded it as part of the sleep cycle.
Stage 1: In this stage of sleep, your eyes move back and forth erratically. Often called REM sleep, this stage occurs at about 90-100 minutes after the onset of sleep. Your blood pressure rises and heart rate and respiration speeds up and becomes erratic.
Your voluntary muscle are paralyzed. This stage may also be referred to as delta sleep and is the most restorative part of sleep. This is also where the majority of your dreaming occurs.
Stage 2: You are entering into light sleep. This stage is characterized by Non-rapid eye movements (NREM), muscle relaxation and slowed heart rate. The body is preparing to enter into deep sleep.
Stage 3 and 4: Also characterized by NREM, these two stages involves periods of deep sleep with Stage 4 being more intense than Stage 3. Your body temperature drops and muscles relaxes. You are completely asleep.
These stages repeat themselves throughout a night’s sleep . Here are some myths about dreaming.
1) Being chased or attacked
More than 80 percent of people dream they’re being pursued or attacked, although who or what is attacking or doing the pursing varies from place to place. These dreams are a natural response to life stress, Garfield says.
The origin of this dream dates back to an era when humans fought off beasts or other tribal members to survive. The “monsters” of today more often are emotional beasts, she says — fear, anxiety, anger, hatred and envy.
Flip side: Being embraced or loved.
These dreams also have early biological roots. They’re driven by our genes to mate and produce children and include the sex dreams. Both men and women, it’s been documented in research, experience sexual arousal during REM sleep. These dreams can supply the desired missing elements in an unsatisfying marriage, or heighten during an intense love affair.
2) Being injured, ill or dying
One myth about dreaming is that if you die in your dream, you die in life.
That’s not true, of course, but dream deaths do occur. They involve deaths of famous people, your parents or children, a lover and even yourself. Garfield believes that when you dream about an accidental death of any person, that person’s death symbolizes something in you that is no longer functioning.
One of the more common scenarios under this theme is of teeth falling out or crumbling.
This might have a physical origin in people gritting or grinding teeth during sleep. Freud suggested that dreams of teeth falling out are related to fears of castration, but women have this dream as often as men, Garfield says. She believes the tooth troubles in dreams are related to anger, with a dreamer acting out the clenching of his teeth. Other psychologists believe the dream reflects anxiety about appearance and how others perceive you.
Flip side: Being healed, born or reborn
Rare, but good, this dream often accompanies a new start, a new job or first day of school. Sometimes dreaming of rebirth represents your hopes for a loved one who has died.
3) Car or other vehicle trouble
Fairly common nightmare among all people and ages, whether or not the dreamers actually drive. Sometimes they have problems with an aircraft they’re flying. May occur when the dreamer feels events in waking life are out of control.
Flip side: Vehicular pleasure
When your time in a car or another vehicle is delightful. This can represent freedom, or moving in the direction of your choice.
4) House or property loss or damage
In these dreams, your house is damaged or destroyed by fire, water or other causes. These dreams may surface because you feel that some valuable aspect of waking life is at risk, she says.
Dreams about losing a wallet, watch or cherished piece of jewelry, such as a wedding ring, also fall into this category. Meanings vary depending on what is lost or damaged. Biologically, they may reflect a basic need to defend your territory.
Flip side: House or property improvement
You may discover new rooms in your home or dream about repairs or improvements. These dreams may occur when you feel that some valuable aspect of waking life is improving.
5) Poor test or other poor performance
You’ve probably dreamed of arriving for a test and found the exam has already started. Or you search fruitlessly for the room. This is a common nightmare and can occur years after you’ve faced the SAT. Garfield says it usually occurs when you feel you are somehow being “tested” in waking life. People continually face situations that challenge their capacity to perform well. This stems from the innate feeling that we need to achieve or compete. Some psychologists think the dreams can denote anxiety about sexual performance.
Flip side: Great test or other fine performance
This may occur when the dreamer feels that she is doing well in waking life. Not limited to exams, the dreamer may envision doing precise spins on the ice or catching a touchdown pass. Sometimes people master certain activities after they’ve successfully performed them in their dream.
6) Falling or drowning
Falling is one of the most common nightmares among people of all ages, and may be a reflection of feeling insecure, helpless or of having no support or solid grounding. Some people may actually fall from their beds during this dream.
Dreaming about drowning is less frequent, and often occurs when a person feels overwhelmed.
Both scenarios involve life-or-death situations and can be traced to prehistoric origins. Garfield says that dreams of falling reflect a time when our ancestors took risks when climbing trees. Falling dreams of modern day often take place from high buildings, elevators and rooftops.
Likewise, dreams of drowning go to our inborn need to breathe for survival.
People often awake to “escape” the danger in the dreams.
A person’s age and medical circumstances can influence these dreams. Toddlers and young children, as well as older people, are prone to more falls in waking life. People with heart conditions that cause fluid buildup in the lungs or those with severe colds may dream of drowning.
Flip side: Flying, swimming or dancing joyfully
Have you had that feeling of zooming through the air, feeling free, unhindered?
Flying often becomes a person’s favorite dream. These can inspire the dreamer, lifting him to spiritual heights or filling him with creative notions. Pleasurable swimming may mean freely exploring your depths; dreams of dance may be a metaphor for moving freely through your life.
7) Being naked in public or inappropriately dressed
This is a common scenario that occurs at all ages, including with children. The dreams involve feelings of exposure and vulnerability, and often include an element of embarrassment or shame.
Appearing partially nude is more common than being totally naked, Garfield says. Meanings vary depending on whether this occurs at school, at work, or on an open street, and depending on what part of the body is exposed.
Wearing the wrong clothing also has various meanings. A bride being inappropriately dressed for her upcoming wedding, for example, could suggest second thoughts she has about the union.
Flip side: Being well dressed
Dreaming of being dapper or wearing a special outfit may suggest you feel good about your body or attractive, or feel good about your life.
8) Missing the boat or other transport
You rush to catch a departing bus, train, airplane or ship, only to have it leave without you. These leave you engulfed in an overwhelming feeling of frustration rather than fear. Garfield suggests that these dreams reflect feelings that you are missing out on something in waking life.
Flip side: Pleasant travel
Very infrequent dreams, but may arise when you feel content about how your life is going.
9) Machine or telephone malfunction
Moderately common, and more frequent in women. These occur when you feel anxious about making an emotional connection or when you feel you’re losing touch with someone. They can relate to mechanical difficulties with your body.
Flip side: Smooth operation
These usually occur when you feel there is an improvement in emotional connection. Garfield says many of the dreamers who participated in her study during bereavement reported dreams of clear connections with their deceased loved ones. Messages they received during the dreams helped them cope with their losses.
10) Natural or man-made disasters
You’re confronted with overwhelming floods, tidal waves earthquakes, volcanic eruptions, tornadoes, hurricanes, bombings or chemical warfare. These dreams may depict personal problems raging out of control.
They can be among the most frightening dreams. People through the ages have sought to harness nature, which can help them survive but also destroy them.
Flip side: Natural beauty, miracles or rituals
Dreams of vibrant flowers, verdant hillsides or uplifting music can leave the dreamer rejuvenated. Color is intensified, with bright yellow-green most often mentioned by dreamers. This may illustrate new growth.
Dreams of natural beauty can inspire and invigorate.
11) Being lost or trapped
In these highly common dreams, you’re lost and feeling desperate. You may be buried alive or locked in a cage. Or you dream of not being able to move; you’re powerless to scream or breathe.
These dreams may occur when you feel confusion or conflict about how to act in waking life.
The images are influenced by biological roots and experience. Feeling trapped or paralyzed also mirrors what occurs to the large muscles of the body during normal REM sleep, when they’re paralyzed to prevent the body from acting out the dreams.
Such dreams could reflect frustrations in waking life, such as feeling trapped in a relationship or a dead-end job.
Flip side: Discovering new spaces
You may open a door in your home to find a new room or find something new in the neighborhood. These dreams occur usually when you feel an aspect of your life if opening up.
12) Being menaced by the dead or a spirit
You feel you are being haunted or berated by someone who has died. There may be
For example, there is evidence that we learn while we sleep. Experiments have associated intense periods of daytime learning with longer periods of sleep that night, and particularly with dreaming. People awakened repeatedly from their dreams don’t retain much of what they learned the day before.
“We see changes in the brain that may be caused by sleep-related learning,” Sutton said. He referred to studies done by him and others in which people sleep in a magnetic resonance imaging (MRI) machine that takes pictures of their brain activity. At the same time, electrodes on their scalp and eyelids record eye movements that indicate dreaming.
“You scan people’s brains before learning, then after sleep,” Sutton explains. “The images let you look at how the brain reorganizes itself.”
In other words, with the right technology it should be possible to see the brain learning.
Sutton’s studies form part of a larger research effort in which computer models of the brain are tested by watching the brain at work, then using the resulting images to correct the models. “We expect this technique will reveal not only what happens in our brains when we sleep and dream, but what brain abnormalities correlate with disorders such as Alzheimer’s disease, stroke, and depression.”
Sleep or Die
No one knows all the purposes of sleeping and dreaming, although lack of sleep can be lethal. Sleep controls heat regulation and appetite. If you’re cold and hungry, you won’t dream much, if at all.
Sleep-deprived rats do okay for a week or two, then their appetites increase dramatically. Even when they get all they want to eat, their weights decrease, their body temperatures become unstable, and they die. Humans deprived of sleep hallucinate and behave abnormally.
Sleep rests the body but not the mind. MRI pictures show furious activity from the base of the brain to its wrinkled covering, the cortex, or thinking dome.
One theory holds that this excitement involves consolidation of information learned during the day. The process could include discarding what the brain considers junk mail, as well as making new connections between brain cells. Called unsupervised learning, the latter produces novel associations and thoughts. You often hear people say, “It came to me in a dream.”
Sutton has watched the sleeping brains of about 15 people. During dreaming, he saw waves of activity starting in the brain stem, moving up through areas concerned with emotion and memory, then spreading over the cortex.
Nerve cells in the brain stem drive sleeping and dreaming by altering the balance of chemicals used to send and receive messages in the brain. The changes quickly travel to other parts of your head.
“The amygdala, an almond-shaped gland responsible for emotion, goes ballistic during dreams,” Sutton says.
Nerve impulses also crackle in cerebral areas concerned with vision, memory, attention, and thought. All this activity is associated with anxiety, joy, anger, sadness, guilt, eroticism, time distortion, bizarre scenes, sudden shifts in subject, and incongruities.
Humans try to make sense of it all by constructing stories that string all these things together, albeit in wacky and weird ways. Sutton thinks such narratives may just be side effects of chemical changes that represent the real purposes of this nervous activity, such as learning and consolidating memories.
“Sleep deprivation impairs learning in humans and animals,” Sutton says. Not just learning after sleep-lack, but before it. Rats make smarter moves when running a maze after a good night’s sleep.
In one series of experiments, people tried to identify the position of objects that they saw quickly displayed on a screen. Researchers thought this skill would be learned immediately by repetition. But, in fact, subjects did better after a restful sleep. To investigate this surprise finding further, the researchers trained people in a repetitive task in the evening before they went to sleep. They then awoke some of them every time sensors on their eyelids showed them to be dreaming. These people retained little. In contrast, other subjects awakened during nondreaming sleep improved overnight.
How come? Studies by Sutton and others pin part of it on a powerful brain chemical called acetylcholine, which passes messages between brain cells. Acetylcholine promotes dreaming and has been implicated in memory consolidation during sleep. Allan Hobson, professor of psychiatry at the Medical School, found a substantial increase in the dreaming of cats when he injected the chemical into their brain stems.
Sutton and Hobson built a computer model that mimics brain changes during sleep and dream. Such a dream machine guides experimenters to pressing questions that need to be answered. The experiments, in turn, feed back new knowledge into the electronic brain.
Dreams To Diagnose Disease
Research on the dreamy role of acetylcholine may lead to a better understanding of Alzheimer’s disease, which involves a disabling loss of memory and the ability to learn. Brain cells that produce this chemical are among the first to degenerate in Alzheimer’s victims.
Michael Hasselmo, an associate professor in the Department of Psychology, has built a computer model to simulate Alzheimer’s. Its learning and memory circuits change with variations in the availability of acetylcholine.
Sutton thinks that by integrating computer models and experimental results on such senility-simulating circuits, it might be possible to see changes that would predict who will get Alzheimer’s. There’s also the hope that such understanding will lead to better treatments for the disease.
Although such possibilities probably lie a long way in the future, they are not totally off-the-wall. Depression, for example, is linked with sleep disturbances. People suffering from it start to dream more quickly than those who do not. “The difference is likely due to an imbalance in brain chemicals, including too much acetylcholine and too little adrenaline,” Sutton explains. Antidepressant drugs are designed to correct the imbalance.
Sutton believes that feedback between his brain machine and MRI pictures of the brain at work will provide more insight not only of depression and Alzheimer’s, but of stroke, multiple sclerosis, and other disorders that affect large areas of the brain.
In one experiment, he and his colleagues looked at pictures of brains while their owners did simple motor tasks, such as tapping their fingers in simple and complex patterns. As expected, they saw activity in small networks of cells located in brain areas that control movements. Interestingly, the same type of brain arousal takes place whether people actually do finger tapping or only imagine it.
What surprised Sutton most, however, was detection of remarkably similar activity in much larger networks spanning areas of the cortex dealing with both input from the senses and output signals to the muscles.
“Patterns of activity in small, more primitive areas of the brain are recapitulated in larger, more advanced parts,” Sutton says. “This means that nature did not have to develop new rules of operation for different levels of the brain from small clusters of cells to large systems.”
In other words, as the brain evolved from a thimbleful of cells in a worm’s head to the billions of cells with trillions of connections in humans, many of the same principles of organization were retained.
Those similarities make it infinitely easier to make computer models of the brain. “We already have built models which allow us to understand what is going on more quickly,” Sutton notes. “Many types of mental illness may result from disorders of this organization. Understanding the details of what is happening will allow us to help real people with real suffering.”