Key Terms

alpha wave

type of rbrain wave characteristic during the early part of NREM stage 1 sleep, which has fairly low amplitude and a frequency of 8–12 Hz

beta wave

type of brain wave characteristic during wakefulness, which has a very low amplitude and a frequency of 13–30 Hz

biological rhythm

internal cycle of biological activity

cataplexy

lack of muscle tone or muscle weakness, and in some cases complete paralysis of the voluntary muscles

central sleep apnea

sleep disorder with periods of interrupted breathing due to a disruption in signals sent from the brain that regulate breathing

circadian rhythm

biological rhythm that occurs over approximately 24 hours

codeine

opiate with relatively low potency often prescribed for minor pain

cognitive-behavioral therapy

psychotherapy that focuses on cognitive processes and problem behaviors that is sometimes used to treat sleep disorders such as insomnia

collective unconscious

theoretical repository of information shared by all people across cultures, as described by Carl Jung

consciousness

awareness of internal and external stimuli

continuous positive airway pressure (CPAP)

device used to treat sleep apnea; includes a mask that fits over the sleeper’s nose and mouth, which is connected to a pump that pumps air into the person’s airways, forcing them to remain open

delta wave

type of brain wave characteristic during stage 3 NREM sleep, which has a high amplitude and low frequency of less than 3 Hz

depressant

drug that tends to suppress central nervous system activity

euphoric high

feelings of intense elation and pleasure from drug use

evolutionary psychology

discipline that studies how universal patterns of behavior and cognitive processes have evolved over time as a result of natural selection

hallucinogen

one of a class of drugs that results in profound alterations in sensory and perceptual experiences, often with vivid hallucinations

homeostasis

tendency to maintain a balance, or optimal level, within a biological system

hypnosis

state of extreme self-focus and attention in which minimal attention is given to external stimuli

insomnia

consistent difficulty in falling or staying asleep for at least three nights a week over a month’s time

jet lag

collection of symptoms brought on by travel from one time zone to another that results from the mismatch between our internal circadian cycles and our environment

K-complex

very high amplitude pattern of brain activity associated with stage 2 sleep that may occur in response to environmental stimuli

latent content

hidden meaning of a dream, per Sigmund Freud’s view of the function of dreams

lucid dream

people become aware that they are dreaming and can control the dream’s content

manifest content

storyline of events that occur during a dream, per Sigmund Freud’s view of the function of dreams

meditation

clearing the mind in order to achieve a state of relaxed awareness and focus

melatonin

hormone secreted by the endocrine gland that serves as an important regulator of the sleep-wake cycle

meta-analysis

study that combines the results of several related studies

methadone

synthetic opioid that is less euphorogenic than heroin and similar drugs; used to manage withdrawal symptoms in opiate users

methadone clinic

uses methadone to treat withdrawal symptoms in opiate users

methamphetamine

type of amphetamine that can be made from pseudoephedrine, an over-the-counter drug; widely manufactured and abused

narcolepsy

sleep disorder in which the sufferer cannot resist falling to sleep at inopportune times

night terror

sleep disorder in which the sleeper experiences a sense of panic and may scream or attempt to escape from the immediate environment

non-REM (NREM)

period of sleep outside periods of rapid eye movement (REM) sleep

obstructive sleep apnea

sleep disorder defined by episodes when breathing stops during sleep as a result of blockage of the airway

opiate/opioid

one of a category of drugs that has strong analgesic properties; opiates are produced from the resin of the opium poppy; includes heroin, morphine, methadone, and codeine

parinsomnia

one of a group of sleep disorders characterized by unwanted, disruptive motor activity and/or experiences during sleep

physical dependence

changes in normal bodily functions that cause a drug user to experience withdrawal symptoms upon cessation of use

pineal gland

endocrine structure located inside the brain that releases melatonin

psychological dependence

emotional, rather than a physical, need for a drug which may be used to relieve psychological distress

rapid eye movement (REM) sleep

period of sleep characterized by brain waves very similar to those during wakefulness and by darting movements of the eyes under closed eyelids

REM sleep behavior disorder (RBD)

sleep disorder in which the muscle paralysis associated with the REM sleep phase does not occur; sleepers have high levels of physical activity during REM sleep, especially during disturbing dreams

restless leg syndrome

sleep disorder in which the sufferer has uncomfortable sensations in the legs when trying to fall asleep that are relieved by moving the legs

rotating shift work

work schedule that changes from early to late on a daily or weekly basis

sleep

state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness

sleep apnea

sleep disorder defined by episodes during which breathing stops during sleep

sleep debt

result of insufficient sleep on a chronic basis

sleep rebound

sleep-deprived individuals will experience shorter sleep latencies during subsequent opportunities for sleep

sleep regulation

brain’s control of switching between sleep and wakefulness as well as coordinating this cycle with the outside world

sleep spindle

rapid burst of high frequency brain waves during stage 2 sleep that may be important for learning and memory

sleepwalking

(also, somnambulism) sleep disorder in which the sleeper engages in relatively complex behaviors

stage 1 sleep

first stage of sleep; transitional phase that occurs between wakefulness and sleep; the period during which a person drifts off to sleep

stage 2 sleep

second stage of sleep; the body goes into deep relaxation; characterized by the appearance of sleep spindles

stage 3 sleep

third stage of sleep; deep sleep characterized by low frequency, high amplitude delta waves

stage 4 sleep

fourth stage of sleep; deep sleep characterized by low frequency, high amplitude delta waves

stimulant

drug that tends to increase overall levels of neural activity; includes caffeine, nicotine, amphetamines, and cocaine

sudden infant death syndrome (SIDS)

infant (one year old or younger) with no apparent medical condition suddenly dies during sleep

suprachiasmatic nucleus (SCN)

area of the hypothalamus in which the body’s biological clock is located

theta wave

type of brain wave characteristic of the end of stage 1 NREM sleep, which has a moderately low amplitude and a frequency of 4–7 Hz

tolerance

state of requiring increasing quantities of the drug to gain the desired effect

wakefulness

characterized by high levels of sensory awareness, thought, and behavior

withdrawal

variety of negative symptoms experienced when drug use is discontinued