Consciousness and Its Variations
KEY POINTS
Introduction: Consciousness: Experiencing the “Private I”
Consciousness refers to your immediate awareness of mental activity, internal sensations, and external stimuli. Most psychologists today consider consciousness an important area of research, as did early psychologists.
Biological and Environmental “Clocks” That Regulate Consciousness
Circadian rhythms are regulated by the suprachiasmatic nucleus (SCN), the “master clock” located in the hypothalamus of the brain. In response to light detected by special photoreceptors, the SCN reduces the production of melatonin by the pineal gland. Increased melatonin makes you sleepy.
In the absence of environmental time cues like sunlight, human circadian rhythms drift toward a 24.2-hour day. Circadian rhythms become disrupted when environmental time cues are out of sync with the body clock. Symptoms of jet lag can be produced by travel across time zones or by rotating shift work.
Sleep
The invention of the electroencephalograph, which produces an EEG or electroencephalogram, and the discovery of rapid eye movements (REM) changed scientific views about sleep. The two basic types of sleep are REM sleep and NREM sleep.
When we are awake and alert, the brain generates beta brain waves. As brain activity gears down and drowsiness sets in, alpha brain waves are generated. Hypnagogic hallucinations can occur during this drowsy, presleep phase.
Each sleep stage is characterized by a specific pattern of brain activity. In the first 90 minutes of sleep, four different stages of NREM sleep are followed by a brief episode of REM sleep. Stage 2 of sleep is defined by the appearance of sleep spindles and K complexes. Throughout the night, episodes of REM sleep become progressively longer and NREM episodes become shorter.
As people age, periods of REM sleep and deep sleep become shorter, and more sleep time is spent in stage 2 NREM.
Sleep is important in maintaining immune function, learning and memory, mood regulation, and other physiological processes. Sleep patterns vary among species and may be the result of evolutionary adaptation. Sleep deprivation studies and the phenomenon of REM rebound demonstrate the biological need to sleep.
Dreams and Mental Activity During Sleep
Sleep thinking occurs during NREM sleep. A dream is a story-like, unfolding episode of mental images that typically occurs during REM sleep but can also occur during NREM.
During REM sleep, the brain is cut off from external stimuli. The frontal lobes and primary visual cortex are inactivated, but the hippocampus, amygdala, and other visual centers are highly active.
Most dreams reflect everyday concerns and include familiar people and settings. Changes in brain chemistry and functioning that occur during sleep probably contribute to the inability to remember dreams. There are individual differences in dream recall. Nightmares are unpleasant anxiety dreams.
Sigmund Freud believed that dream images are symbols of unconscious wishes. According to Freud, dreams are composed of manifest content and latent content. The activation-synthesis model of dreaming proposes that dreams reflect our subjective awareness of brain activation during sleep. According to the neurocognitive model of dreaming, dreaming cognition is similar to waking cognition.
Sleep Disorders
Sleep disorders are serious disturbances in the normal sleep pattern that interfere with daytime functioning and cause subjective distress.
Dyssomnias, such as insomnia and obstructive sleep apnea (OSA), involve interruptions in the amount, quality, or timing of sleep. The symptoms of narcolepsy, including cataplexy, are experienced during the day. Narcolepsy may be associated with low levels of hypocretins. Parasomnias involve undesirable physical arousal, behavior, or events during sleep or sleep transitions; examples include sleepwalking, sleep terrors, sleep-related eating disorders, and sleepsex.
Hypnosis
Hypnosis is an unusual state of awareness, defined as a cooperative social interaction in which the hypnotic participant responds to suggestions made by the hypnotist. Changes in perception, memory, and behavior may be produced. People vary in hypnotic susceptibility.
Under hypnosis, profound sensory and perceptual changes may be experienced, including pain reduction and hallucinations. Posthypnotic suggestions influence behavior outside the hypnotic state. Hypnosis is used in habit control, but its effectiveness varies. Hypnosis can produce posthypnotic amnesia. Although hypnosis does not increase the accuracy of memories, it does increase confidence in memories and can produce false memories. Hypnosis cannot be used to make people perform behaviors that are contrary to their morals or values.
The neodissociation theory of Ernest Hilgard explains hypnosis as involving dissociation and a hidden observer. Some psychologists believe that hypnosis is not a special state of consciousness but can be explained by social and cognitive processes.
Meditation
Meditation techniques induce a state of focused attention and heightened awareness. Two forms of meditation are focused awareness and open monitoring.
Early research on meditation emphasized stress relief and relaxation. Research today studies meditation’s effects on the brain and basic psychological processes, including attention, memory, cognition, and emotion. Meditation techniques are also used in psychotherapy.
Psychoactive Drugs
Psychoactive drugs can alter arousal, mood, thinking, sensation, and perception. Many psychoactive drugs are addictive, producing physical dependence and drug tolerance. The physically dependent person who stops taking a drug experiences withdrawal symptoms, which often include the drug rebound effect.
Psychoactive drugs affect brain activity by influencing synaptic transmission. Drug effects can be influenced by the person’s weight, gender, race, metabolic rate, and the presence of other drugs. Personality characteristics, mood, expectations, experience with the drug, and the setting in which the drug is taken also affect the drug response.
Drug abuse (formally called substance use disorder) refers to recurrent substance use that involves impaired control, disruption of social, occupational, and interpersonal functioning, and the development of craving, tolerance, and withdrawal symptoms.
Depressants are physically addictive drugs that inhibit central nervous system activity. Depressants include alcohol, barbiturates, inhalants, and tranquilizers. Psychologically, alcohol lessens inhibitions, but its effects vary, depending on the person’s environment and expectations. Barbiturates and inhalants produce relaxation and reduce inhibitions.
Opioids are addictive drugs, chemically similar to morphine, that relieve pain and produce feelings of euphoria. The opiates include opium, morphine, codeine, heroin, methadone, and prescription painkillers. Opioids relieve pain by mimicking the effect of endorphins in the brain.
Stimulants include caffeine, nicotine, amphetamines, and cocaine. The stimulants increase brain activity, and all stimulants are addictive. Prolonged use of amphetamines or cocaine can lead to stimulant-induced psychosis.
Psychedelic drugs include mescaline, LSD, and marijuana. The psychedelics create perceptual distortions, alter mood, and affect thinking. Although psychedelic drugs are not physically addictive, they can cause a variety of harmful effects.
The “club drugs” are synthetic drugs used at dance clubs, parties, and “raves.” These drugs include MDMA (ecstasy) and the dissociative anesthetics PCP and ketamine.
Match each of the terms on the left with its definition on the right. Click on the term first and then click on the matching definition. As you match them correctly they will move to the bottom of the activity.
meditation melatonin mescaline narcolepsy neodissociation theory of hypnosis neurocognitive model of dreaming nicotine nightmare NREM sleep obstructive sleep apnea opioids parasomnias physical dependence posthypnotic amnesia posthypnotic suggestion psychedelic drugs psychoactive drug REM rebound REM sleep sleep disorders sleep paralysis sleep spindles sleep terrors sleep thinking sleep-related eating disorder (SRED) sleepsex sleepwalking stimulant-induced psychosis stimulants stimulus control therapy suprachiasmatic nucleus (SCN) tranquilizers withdrawal symptoms activation-synthesis model of dreaming alpha brain waves amphetamines attention barbiturates beta brain waves caffeine cataplexy circadian rhythm cocaine consciousness depressants dissociation dissociative anesthetics dream drug abuse drug rebound effect drug tolerance dyssomnias EEG (electroencephalogram) electroencephalograph hidden observer hypnagogic hallucinations hypnosis inhalants insomnia K complex latent content LSD manifest content marijuana MDMA or ecstasy | The graphic record of brain activity produced by an electroencephalograph. Any one of a number of sustained concentration techniques that focus attention and heighten awareness. An instrument that uses electrodes placed on the scalp to measure and record the brain's electrical activity. Quiet, typically dreamless sleep in which rapid eye movements are absent; divided into four stages; also called quiet sleep. Type of sleep during which rapid eye movements (REM) and dreaming usually occur and voluntary muscle activity is suppressed; also called active sleep or paradoxical sleep. A hormone manufactured by the pineal gland that produces sleepiness. Short bursts of brain activity that characterize stage 2 NREM sleep. A temporary condition in which a person is unable to move upon awakening in the morning or during the night. Depressant drugs that relieve anxiety. A psychedelic drug derived from the peyote cactus. A stimulant drug derived from the coca tree. Theory proposed by Ernest Hilgard that explains hypnotic effects as being due to the splitting of consciousness into two simultaneous streams of mental activity, only one of which the hypnotic participant is consciously aware of during hypnosis. In Freud's psychoanalytic theory, the unconscious wishes, thoughts, and urges that are concealed in the manifest content of a dream. Unpleasant physical reactions, combined with intense drug cravings, that occur when a person abstains from a drug on which he or she is physically dependent. Withdrawal symptoms that are the opposite of a physically addictive drug's action. A condition in which increasing amounts of a physically addictive drug are needed to produce the original, desired effect. A suggestion made during hypnosis asking a person to carry out a specific instruction following the hypnotic session. In Freud's psychoanalytic theory, the elements of a dream that are consciously experienced and remembered by the dreamer. The capacity to selectively focus awareness on particular stimuli in your external environment or on your internal thoughts or sensations. Hilgard's term for the hidden, or dissociated, stream of mental activity that continues during hypnosis. A phenomenon in which a person who is deprived of REM sleep greatly increases the amount of time spent in REM sleep at the first opportunity to sleep without interruption. An unfolding sequence of thoughts, perceptions, and emotions that typically occurs during REM sleep and is experienced as a series of real-life events. A cycle or rhythm that is roughly 24 hours long; the cyclical daily fluctuations in biological and psychological processes. A class of stimulant drugs that arouse the central nervous system and suppress appetite. A sleep disorder characterized by excessive daytime sleepiness and brief lapses into sleep throughout the day. Recurrent substance use that involves impaired control, disruption of social, occupational, and interpersonal functioning, and the development of craving, tolerance, and withdrawal symptoms. Vivid sensory phenomena that occur during the onset of sleep. Model of dreaming that emphasizes the continuity of waking and dreaming cognition, and states that dreaming is like thinking under conditions of reduced sensory input and the absence of voluntary control. A sudden loss of voluntary muscle strength and control that is usually triggered by an intense emotion. The splitting of consciousness into two or more simultaneous streams of mental activity. A drug that alters consciousness, perception, mood, and behavior. A sleep disturbance characterized by an episode of walking or performing other actions during stage 3 or stage 4 NREM sleep; also called somnambulism. A cooperative social interaction in which the hypnotized person responds to the hypnotist's suggestions with changes in perception, memory, and behavior. A vivid and frightening or unpleasant anxiety dream that occurs during REM sleep. A category of psychoactive drugs that increase brain activity, arouse behavior, and increase mental alertness. A synthetic psychedelic drug. A stimulant drug found in coffee, tea, cola drinks, chocolate, and many over-the-counter medications. A category of psychoactive drugs that create sensory and perceptual distortions, alter mood, and affect thinking. A sleep disorder in which the person repeatedly stops breathing during sleep. A category of psychoactive drugs that are chemically similar to morphine and have strong pain-relieving properties; also called opiates or narcotics. Vague, bland, thoughtlike ruminations about real-life events that typically occur during NREM sleep; also called sleep mentation. Single but large high-voltage spike of brain activity that characterizes stage 2 NREM sleep. The inability to recall specific information because of a hypnotic suggestion. A category of sleep disorders characterized by arousal or activation during sleep or sleep transitions; includes sleepwalking, sleep terrors, sleepsex, sleep-related eating disorder, and REM sleep behavior disorder. Class of drugs that reduce sensitivity to pain and produce feelings of detachment and dissociation; includes the club drugs phencyclidine (PCP) and ketamine. A stimulant drug found in tobacco products. Personal awareness of mental activities, internal sensations, and the external environment. A category of sleep disorders involving disruptions in the amount, quality, or timing of sleep; includes insomnia, obstructive sleep apnea, and narcolepsy. Brain-wave pattern associated with relaxed wakefulness and drowsiness. Insomnia treatment involving specific guidelines to create a strict association between the bedroom and rapid sleep onset. A sleep disorder involving abnormal sexual behaviors and experiences during sleep; also called sexsomnia. A category of depressant drugs that reduce anxiety and produce sleepiness. Brain-wave pattern associated with alert wakefulness. A cluster of neurons in the hypothalamus in the brain that governs the timing of circadian rhythms. Serious and consistent sleep disturbances that interfere with daytime functioning and cause subjective distress. A category of psychoactive drugs that depress or inhibit brain activity. A condition in which a person has physically adapted to a drug so that he or she must take the drug regularly in order to avoid withdrawal symptoms. Chemical substances that are inhaled to produce an alteration in consciousness. Schizophrenia-like symptoms that can occur as the result of prolonged amphetamine or cocaine use; also called amphetamine-induced psychosis or cocaine-induced psychosis. A condition in which a person regularly experiences an inability to fall asleep, to stay asleep, or to feel adequately rested by sleep. Synthetic club drug that combines stimulant and mild psychedelic effects. A sleep disturbance characterized by an episode of increased physiological arousal, intense fear and panic, frightening hallucinations, and no recall of the episode the next morning; typically occurs during stage 3 or stage 4 NREM sleep; also called night terrors. The theory that brain activity during sleep produces dream images (activation), which are combined by the brain into a dream story (synthesis). A psychoactive drug derived from the hemp plant. A sleep disorder in which the sleeper will sleepwalk and eat compulsively. |
Sigmund Freud (1856–
Ernest R. Hilgard (1904–
Robert W. McCarley (b. 1937) Contemporary American psychiatrist and neuroscientist who has extensively studied the brain controls involved in sleep and dreaming; along with co-researcher J. Allan Hobson, proposed the activation-synthesis model of dreaming.
J. Allan Hobson (b. 1933) Contemporary American psychiatrist and neuroscientist who has extensively studied the neuropsychological events associated with sleep and dreaming; along with co-researcher Robert W. McCarley, proposed the activation-synthesis model of dreaming.
William James (1842–
SOLUTION TO FIGURE 4.1
FIGURE 4.1: Can We Read Your Mind? Explanation: Look once more at the six cards on page 136, and then compare them with the five cards pictured on page 138. Notice any differences? If the act of circling an eye distracted you and you fell for the trick—as most people do—you have just experienced change blindness.