Psychology Chapter 4: Consciousness – Flashcards

Early psychologists saw consciousness, or awareness, as psychological in nature. Freud distinguished between con- scious and unconscious experiences. James emphasized the continuous flow of thought and feeling in consciousness. Today's psychologists view consciousness as a neurobiological phenomenon rather than an exclusively psychological one. (pp. 116-117)

Practices in many cultures allow individuals to deliberately induce altered states, often as part of tribal ceremonies or religious rituals. (pp. 117-118)

The suprachiasmatic nucleus (SCN) is the body's biologi- cal clock, which regulates circadian rhythms and signals the pineal gland to secrete or suppress secretion of melatonin, a hormone that acts to induce sleep. The amount of melatonin released by the pineal gland depends on the amount of light perceived by specialized photoreceptor cells on the retina. (pp. 118-119)

Jet lag and shift work disrupt circadian rhythms, which can lead to sleep difficulties as well as reduced alertness during periods of wakefulness. (pp. 119-120)

The restorative theory of sleep claims that being awake causes stress on the body and the brain; repairs are made during sleep. The circadian (evolutionary) theory maintains that cir- cadian rhythms, which evolved to protect humans from pred- ators during the night, dictate periods of sleep and alertness. (p. 120)

During a typical night of sleep, a person goes through about five sleep cycles, each lasting about 90 minutes. During NREM sleep, heart rate and respiration are slow and regular, and blood pressure and brain activity are at a 24-hour low point; there is little body movement and no rapid eye movements. During REM sleep, the large muscles of the body are para- lyzed, respiration and heart rate are fast and irregular, brain activity increases, and rapid eye movements and vivid dreams occur. REM sleep appears to be essential to the consolidation of memories. The first sleep cycle contains Stages 1, 2, 3, and 4 of NREM sleep as well as a period of REM sleep; the second con- tains Stages 2, 3, and 4 of NREM sleep and a period of REM sleep. In the third cycle, only Stages 2 and 3 are present, along with a period of REM sleep. In the remaining sleep cycles, the sleeper alternates mainly between Stage 2 and REM sleep, with each sleep cycle having progressively longer periods of REM. (pp. 120-122)

Infants and young children have the longest sleep time and largest percentages of REM and slow-wave sleep. Children from age 6 to puberty sleep best. Older adults typically have shorter total sleep time, more awakenings, and substantially less slow-wave sleep. (pp. 122)

Sleep deprivation can lead to lapses in concentration and emotional irritability. Research examining the effects of sleep deprivation on verbal learning have shown that sleep depriva- tion may lead to suppression of neurological activity in the temporal lobes. (p. 123)

Parasomnias occur during partial arousal from Stage 4 sleep. In a sleep terror, the sleeper awakens in a panicked state with a rac- ing heart. Episodes last 5 to 15 minutes, and then the person falls back to sleep. Nightmares occur during REM sleep and are usu- ally remembered in vivid detail. Somniloquy (sleeptalking) can occur during any sleep stage and is more common in children than adults. The symptoms of narcolepsy include excessive day- time sleepiness and sudden attacks of REM sleep. Sleep apnea is a sleep disorder in which a sleeper's breathing stops and the per- son must awaken briefly to breathe. Its symptoms are excessive daytime sleepiness and loud snoring. Insomnia is a sleep disor- der characterized by difficulty falling or staying asleep, waking too early, or sleep that is light, restless, or of poor quality. (pp. 123-125)

REM dreams have a story-like or dreamlike quality and are more visual, vivid, and emotional than NREM dreams. Common dream themes include falling or being attacked or chased. During REM dreams, areas of the brain responsible for emotions and the primary visual cortex are active, but the neurotransmitters serotonin and norepinephrine are less plen- tiful. Lucid dreaming is a set of techniques that enables dream- ers to exert cognitive control over the content of their dreams. (p. 126)

Freud claimed that dreams carry hidden meanings and function to satisfy unconscious sexual and aggressive desires. He claimed that the manifest content of dreams differs from their latent content. Today, some psychologists support the cognitive theory of dreaming, which claims that dreaming is thinking while asleep; others support the activation-synthesis hypothesis, which claims that dreams are the brain's attempt to make sense of the random firing of brain cells during REM sleep and others support the evolutionary theory of dreaming, which says that vivid REM dreams enable people to rehearse the skills they need to fend off predators. (pp. 126-128)

Meditation promotes relaxation, reduces arousal, or expands consciousness. It may also help prevent and treat cardiovas- cular disease. (pp. 128-129)

Hypnosis is a procedure through which a hypnotist uses the power of suggestion to induce changes in the thoughts, feelings, sensations, perceptions, or behavior of a subject. It has been used most successfully for the control of pain. The three main theories proposed to explain hypnosis are the sociocognitive theory, the neodissociation theory, and the theory of dissociated control. (pp. 129-130)

Psychoactive drugs increase the availability of dopamine in the nucleus accumbens. Beyond that, each drug has a unique influence on a specific neurotransmitter or group of neurotransmitters. (p. 131)

With physical drug dependence, the user develops a drug tol- erance, and so larger and larger doses of the drug are needed to get the same effect or high. Withdrawal symptoms appear when the drug is discontinued and disappear when the drug is taken again. Psychological drug dependence involves an intense craving for the drug's pleasurable effects. (pp. 131-133)

Stimulants (amphetamines, cocaine, caffeine, and nicotine) speed up activity in the central nervous system, suppress appe- tite, and make a person feel more awake, alert, and energetic. (pp. 133-134)

Depressants decrease activity in the central nervous system, slow down bodily functions, and reduce sensitivity to outside stimulation. Depressants include sedative-hypnotics (alcohol, barbiturates, and minor tranquilizers) and narcotics (opiates such as opium, codeine, morphine, and heroin), which have both pain-relieving and calming effects. (pp. 134-135)

Hallucinogens—including marijuana, LSD, and MDMA— can alter and distort perceptions of time and space, alter mood, produce feelings of unreality, and cause hallucinations. (pp. 135-137)