Our daily schedule of waking and sleeping is governed by a biological clock known as circadian rhythm. Our sleep also follows a repeating cycle. Awakening people during REM sleep yields predictable “dreamlike” reports that are mostly of ordinary events. Freud’s view that dreams can be traced back to erotic wishes is giving way to newer theories, for example, that dreams help us process information and fix it in memory or that dreams erupt from neural activity.
Studies of hypnosis indicate that, although hypnotic procedures may facilitate recall, the hypnotist’s beliefs frequently work their way into subjects’ recollections. Hypnosis can be at least temporarily therapeutic and has the potential of bringing significant pain relief. Hypnosis may be an extension both of normal principles of social influence and of everyday splits in consciousness.
Psychoactive drugs also alter consciousness. Depressants act by depressing neural functioning. Although their effects are pleasurable, they impair memory and self-awareness and may have other physical consequences. Stimulants act at the synapses by influencing the brain’s neurotransmitters. Their effects depend on dosage and the user’s personality and expectations. Hallucinogens can distort
judgment of time and can alter sensations and perceptions. A number of those who survive a brush with death later recall visionary experiences. Some scientists point out that such near-death experiences closely parallel reports of hallucinations and
may be a product of a brain under stress. Others reject this analysis.
Psychology began as the study of consciousness, our awareness of ourselves and our environment. But the difficulty of scientifically studying consciousness led many psychologists to turn to direct observations of behavior. By the middle of the twentieth century psychology was defined as the science of behavior. By 1960, mental concepts began to reenter psychology, and today, investigating
states of mind is again one of psychology’s pursuits. Advances in neuroscience made it possible to relate brain activity to sleeping, dreaming, and other mental states.
Sleep and Dreams
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Our daily schedule of waking and sleeping is governed by a biological clock known as circadian rhythm. Our body temperature rises as morning approaches, peaks during the day, dips for a time in early afternoon, and then begins to drop again before we go to sleep. Thinking is sharpest and memory most accurate when people are at their peak in circadian arousal. This cycle is in part a response to light striking the retina, signaling the suprachiasmatic nucleus in the hypothalamus to trigger alterations in the level of biochemical substances, including decreased output of sleep-inducing melatonin by the pineal gland. The cycle lasts about 24 hours, but it can be disrupted by bright light, time changes, and alterations in our sleep schedule (such as staying up late and sleeping in on weekends).
We pass through a cycle of five sleep stages that total about 90 minutes. As we lie awake and relaxed, before we sleep, our EEG shows relatively slow alpha waves. Stage 1 sleep is characterized by fantastic images resembling hallucinations (hypnagogic sensations). Stage 2 sleep (the stage in which we spend the most time) follows about 20 minutes later, with its characteristic sleep
spindles. Starting in Stage 3 and increasingly in Stage 4, the brain emits large, slow delta waves. These two slow-wave sleep stages last for about 30 minutes, during which we are hard to awaken. Reversing course, we retrace our path through these stages with one difference. About an hour after falling asleep, we begin approximately 10 minutes of REM (rapid eye movement) sleep in
which most dreaming occurs. In this fifth stage (also known as paradoxical sleep), we are internally aroused but outwardly paralyzed. The sleep cycle repeats several times during a normal night’s sleep, with periods of Stage 4 sleep progressively shortening and periods of REM sleep lengthening.
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People differ in their individual sleep requirements. For example, newborns sleep twice as much as adults. These age-related changes are rivaled by differences in the normal amount of sleep among individuals of any age. Twin studies suggest that these differences may be partially genetic. Sleep patterns are also culturally influenced. People in modern industrialized nations get less sleep
because of shift work and social diversions, for example.
People today suffer from sleep patterns that thwart their having an energized feeling of well-being. Findings suggest that sleep deprivation puts people at risk for a depressed immune system; impaired concentration, creativity, and communication; irritability; and slowed performance with greater vulnerability to accidents. Chronic sleep deprivation can also alter metabolic and hormonal function, creating conditions that may contribute to obesity, hypertension, and memory impairment.
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The first explanation of why we sleep is that sleep may have played a protective role in human evolution by keeping people safe during potentially dangerous times. A second idea is that sleep may help us recuperate, restoring and repairing brain tissue. A third explanation is that sleep restores and rebuilds our fading memories of the day’s experiences. People trained to perform tasks recall them better even after a short nap. A fourth possible reason why we sleep is that sleep feeds creative thinking. After working on a task, then sleeping on it, people solve problems more insightfully than do those who stay awake. Finally, sleep may play a role in the growth process. During deep sleep, the pituitary gland releases a growth hormone.
One in 10 adults, and 1 in 4 older adults, complain of insomnia—problems in falling or staying asleep. Rarer but more severe than insomnia are the sleep disorders narcolepsy and sleep apnea. People with narcolepsy suffer periodic, overwhelming sleepiness, sometimes at the most inopportune times. The person sometimes collapses directly into a brief period of REM sleep. Those who suffer sleep apnea (mostly overweight men) intermittently stop breathing during sleep. After an airless minute or so, decreased blood oxygen arouses the sleeper to snort in air for a few seconds. Still other sleepers, mostly children, experience night terrors. They sit up or walk around, talk incoherently, experience a doubling of heart and breathing rates, and appear terrified. Children also are most prone to sleepwalking.
Our dreams are mostly of ordinary events; they often relate to everyday experiences and more frequently involve anxiety or misfortune than triumphant achievement. The story line of our dreams—what Sigmund Freud called their manifest content—sometimes incorporates traces of previous days’ experiences and preoccupations. Only 1 in 10 dreams among young men and 1 in 30 among young women have sexual overtones. The sensory stimuli of our environment may also intrude on our dreams.
Freud believed that a dream’s manifest content is a censored version of its latent content, which gratifies our unconscious wishes. The information-processing perspective suggests that dreams help us process information and fix it in memory. Some physiological theories propose that REMinduced regular brain stimulation helps develop and preserve neural pathways in the brain. The activation-synthesis explanation is that REM sleep triggers impulses in brain areas that process visual images, but not the visual cortex area, evoking visual images that our brain weaves into a story line. The brain-maturation/cognitive development perspective maintains that dreams represent
the dreamer’s level of development, knowledge, and understanding. Despite their differences, most theorists agree that REM sleep and its associated dreams serve an important function, as shown by the REM rebound that occurs following REM deprivation.
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Hypnosis is a social interaction in which one person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.
People who are highly hypnotizable frequently become deeply absorbed in imaginative activities. They have the ability to focus attention totally on a task. Hypnosis does not enhance recall of forgotten events and may even foster false memories. Research indicates that hypnotized people cannot be made to act against their will any more than nonhypnotized people can and that hypnosis can be at least temporarily therapeutic. Posthypnotic suggestions have helped people to reduce headaches, asthma, stress-related skin disorders, and behaviors related to obesity. However, drug, alcohol, and smoking addictions have not responded well to hypnosis. Hypnotizable people can enjoy significant pain relief. One theory finds the answer to pain relief in dissociation, a split between different levels of consciousness.
The belief that hypnosis produces a dissociation gains support from the fact that hypnotized subjects sometimes carry out suggested behaviors on cue, even when they believe no one is watching them. Furthermore, hypnosis is accompanied by distinctive brain activity. The divided consciousness theory of hypnosis argues that hypnosis involves dissociation that is more extreme than the everyday dissociations that occur in our information processing. Hilgard suggests that dissociation accounts for a hypnotized subject’s awareness of experiences that go unreported during hypnosis.
Other psychologists argue that hypnosis is a by-product of normal social and cognitive processes and thus not a unique state of consciousness. These advocates of social influence theory note that behaviors produced through hypnotic procedures can also be produced without them. “Hypnotized” people may be acting the role of “good hypnotic subjects” and allowing the hypnotist to direct their fantasies. Evidence for this view comes from experiments in which the researcher tells hypnotized subjects that hypnosis reveals their gullibility, and they stop respondingas directed. Most recently, researchers are moving toward a unified account of hypnosis, a merging of the two views.
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Drugs and Consciousness
Psychoactive drugs are chemicals that change perceptions and moods. Continued use of a psychoactive drug produces tolerance, and cessation of use may produce the undesirable side effects of withdrawal. The pain of withdrawal and intense craving for a dose indicates a physical dependence. People can also develop psychological dependence, particularly for drugs used to relieve stress. An addiction is a compulsive craving for a substance despite adverse consequences. It is often marked by physical symptoms such as aches, nausea, and distress following sudden withdrawal.
Many drug researchers believe the following three common misconceptions about addiction are false: (1) Medical drugs, for example, those used to control pain, are powerfully addictive; (2) addictions cannot be overcome voluntarily but only through treatment; and (3) we can extend the concept of addiction to cover a whole spectrum of repetitive, pleasure-seeking behaviors, such as overeating, exercise, gambling, sex, and surfing the Internet.
Psychoactive drugs operate at the brain’s synapses by stimulating, inhibiting, or mimicking the activity of neurotransmitters, the brain’s chemical messengers. Our culturally influenced expectations also play a role in the effects of drugs.
Depressants such as alcohol, the barbiturates, and the opiates act by reducing neural activity and slowing body functions. Each offers its own pleasures, but at the cost of impaired memory and self-awareness or other physical consequences. Alcohol is a disinhibitor and thus increases the likelihood that we will act on both helpful and harmful impulses. It also impairs judgment, reduces self-awareness, and disrupts memory processes by suppressing REM sleep. Research indicates that when people believe that alcohol affects social behavior in specific ways, and believe that they have been drinking alcohol, they will behave accordingly. Studies find drinking and risky sex to be
highly correlated. Barbiturates, or tranquilizers, mimic the effects of alcohol. In combination with alcohol, they can be lethal. The opiates also depress neural functioning and can cause the brain to stop producing its own opiates, the endorphins.
Stimulants, such as caffeine, nicotine, and the amphetamines and the even more powerful cocaine, Ecstasy, and methamphetamines, excite neural activity and arouse body functions. As with nearly all psychoactive drugs, they act at the synapses by influencing the brain’s neurotransmitters, andtheir effects depend on dosage and the user’s personality and expectations. Methamphetamine is
highly addictive; over time, it appears to reduce baseline dopamine levels. Nicotine triggers the release of epinephrine and norepinephrine, which in turn diminish appetite and boost alertness and mental efficiency. Cocaine produces a euphoric rush that lasts 15 to 30 minutes and depletes the brain’s supply of the neurotransmitters dopamine, serotonin, and norepinephrine. A crash of agitated depression follows as the drug’s effects wear off. Regular users become addicted and may experience emotional disturbance, suspiciousness, convulsions, cardiac arrest, or respiratory failure. Ecstasy (MDMA) is both a stimulant and a mild hallucinogen. By releasing serotonin and blocking
its reuptake, it produces euphoria and feelings of intimacy. Its repeated use may suppress the immune system, destroy serotonin-producing neurons, and permanently damage mood.
Hallucinogens distort perceptions and evoke sensory images in the absence of sensory input. LSD and other powerful hallucinogens are chemically similar to (and therefore block the actions of) a subtype of the neurotransmitter serotonin. Common components of the LSD experience are hallucinations and emotions ranging from euphoria to panic. A person’s current mood and expectations affect the drug’s effects.
The sensations produced by LSD are strikingly similar to the near-death experience, an altered state of consciousness reported by about one-third of those who survive a brush with death. Neardeath experiences are marked by out-of-body sensations, visions of tunnels and bright lights, and intense feelings of joy, love, and peace. The hallucinations of such experiences also closely parallel
the hallucinations produced by loss of oxygen or extreme sensory deprivation. Marijuana’s main active ingredient, THC, produces a variety of effects, including disinhibition, a euphoric high, feelings of relaxation, relief from pain, and intense sensitivity to colors, sounds,
tastes, and smells. It may also increase anxiety or depression, impair motor coordination and reaction time, and disrupt memory formation. Because THC lingers in the body for a month or more, regular users may achieve a high with smaller amounts of the drug than do occasional users.
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Drug use among U.S. high school seniors declined from 1978 to 1992, then rose, but has recently been tapering off. Various studies indicate that some people are biologically more likely to become dependent on drugs. For example, researchers have identified genes that are more common among people and animals predisposed to alcohol dependence. These genes may produce deficiencies in
the brain’s natural dopamine reward system. One psychological factor that contributes to drug use is the feeling that one’s life is meaningless and directionless. Studies reveal that heavy drug users often have experienced significant stress or failure and are depressed. Drug use can also have social roots, evident in differing rates of drug use across cultural and ethnic groups. In the United States, drug addiction rates are very low among the Amish, Mennonites, Mormons, and Orthodox Jews. Peer pressure may lead people, especially teenagers, to experiment with—and become dependent on—drugs. Possible avenues for treatment and prevention involve education, boosting people’s self-esteem and purpose in life, and inoculation against peer pressure.
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Work Cited: All summary notes come from *Myers Pyschology for AP, Lecture Guides (2011 Worth Publishers)