Circandian Rhythm
• A cycle or rhythm this is roughly 24 hours
long; the cyclical daily fluctuations in
biological and psychological process
Superchiasmatic nucle us (SCN)
• A cluster of neurons in the hypothalamus in
the brain that governs the timing of
circadian rhythms
Melatonin
• A hormone manufactured by the pineal
gland that produces sleepiness
Electroencephalograph
• An instrument that uses electrodes placed
on the scale to measure and record the
brain’s electrical activity
EEG (electroencephalogram)
• The graphic record of brain activity
produced by an electroencephalograph
REM sleep
• Type of sleep during which rapid eye
movements and dreaming usually occur and
voluntary muscle activity is suppressed:
also called active sleep or paradoxical sleep
NREM Sleep
• Quiet typically dreamless sleep in which
rapid eye movements are absent; divided
into four stages; also called quiet sleep
Beta brain waves
• Brain-wave pattern associated with alert
wakefulness
Alpha brain waves
• Brain-wave pattern associated with relaxed
wakefulness and drowsiness
Hypnagogic hallucinations
• Vivid sensory phenomena that occur during
the onset of sleep
Sleep spindles
• Short bursts of brain activity that
characterize stage 2 NREM sleep
K complex
• Single but large high-voltage spike of brain
activity that characterizes stage 2 NREM
sleep
REM rebound
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 uninterrupted
Restorative theory of sleep
The view that sleep and dreaming are
essential to normal physical and mental
functioning
Adaptive theory of sleep
The view that the unique sleep patterns of
different animals evolved over time to help
promote survival and environmental
adaptation; also referred to as the
evolutionary theory of sleep
Sleep disorders
Serious disturbances in the normal sleep
pattern that interfere with daytime
functioning and cause subjective distress
Insomnia
A condition in which a person regularly
experiences an inability to fall asleep, to
stay asleep, or to feel adequately rested by
sleep
Restless legs syndrome (RLS)
A condition in which unpleasant sensations in
the lower legs are accompanied by an
irresistible urge to move the legs,
temporarily relieving the unpleasant
sensation but disrupting sleep
Sleep apnea
A sleep disorder in which the person
repeatedly stops breathing during sleep
Sleepwalking
A sleep disturbance characterized by an
episode of walking or performing other
actions during stage 3 or stage 4 NREM
sleep; also called somnambulism
Night terrors
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
sleep terrors
Parasomnias
A category of sleep disorders characterized by
arousal or activation during sleep or sleep
transitions; includes sleepwalking, night
terrors, sleep bruxism, and REM sleep
behavior disorder
REM sleep behavior disorder
A sleep disorder in which the sleeper acts out
his or her dreams
Dream
A storylike episode of unfolding mental
imagery during sleep
Nightmare
A frightening or unpleasant anxiety dream that
occurs during REM sleep
Manifest content
In Freud’s psychoanalytic theory, the elements
of a dream that are consciously experienced
and remembered by the dreamer
Latent content
In Freud’s psychoanalytic theory, the
unconscious wishes, thoughts, and urges
that are concealed in the manifest content of
a dream
Activation-synthesis model of
dreaming
The theory that brain activity during sleep
images (activation), which are combined by
the brain into a dream story (synthesis)
Hypnosis
A cooperative social interaction in which the
hypnotized person responds to the
hypnotist’s suggestions which changes in
perception, memory, and behavior
Posthypnotic suggestion
A suggestion made during hypnosis that the
person should carry out a specific
instruction following the hypnotic session
Posthypnotic amnesia
The inability to recall specific information
because of a hypnotic suggestion
Hypermnesia
The supposed enhancement of a person’s
memory for past events through a hypnotic
suggestion
Dissociations
The splitting of consciousness into two or
more simultaneous streams of mental
activity
Neodissoication theory of
hypnosis
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
Hidden observer
Hilgard’s term for the hidden, or dissociated
stream of mental activity during hypnosis
Meditation
Any one of a number of sustained
concentration techniques that focus
attention and heighten awareness
Psychoactive drug
A drug that alters consciousness, perception,
mood, and behavior
Physical dependence
A condition in which a person has physically
adapted to a drug so that he or she must take
the drug regularly in order avoid withdrawal
symptoms
Drug tolerance
A condition in which increasing amounts of a
physically addictive drug are needed to
produce the original, desired effect
Withdrawal symptoms
Unpleasant physical reactions, combined with
intense drug cravings, that occur when a
person abstains from a drug on which he or
she is physically dependant
Drug rebound effect
Withdrawal symptoms that are the opposite of
a physically addictive drug’s action
Drug abuse
Recurrent drug use that results in disruptions
in academic, social, or occupational
functioning or in legal or psychological
problems
Depressants
A category of psychoactive drugs that depress
or inhibit brain activity
Barbiturates
A category of depressant drugs that reduce
anxiety and produce sleepiness
Tranquilizers
Depressant drugs that relieve anxiety
Inhalants
Chemical substances that are inhaled to
produce an alteration in consciousness
Opiates
A category of psychoactive drugs that are
chemically similar to morphine and have
strong pain-relieving properties
Stimulants
A category of psychoactive drugs that
increase brain activity, arouse behavior, and
increase mental alertness
Caffeine
A stimulant drug found in coffee, tea, cola
drinks, chocolate, and many over-thecounter medications
Nicotine
A stimulant drug found in tobacco products
Amphetamines
A class of stimulant drugs that arouse the
central nervous system and suppress
appetite
Cocaine
A stimulant drug derived from the coca tree
Stimulant-induced psychosis
Schizophrenia-like symptoms that can occur
as the result of prolonged amphetamine or
cocaine use; also called amphetamine
psychosis or cocaine psychosis
Psychedelic drugs
A category of psychoactive drugs that create
sensory and perceptual distortions, alter
mood, and affect judgment
Mescaline
A psychedelic drug derived from the peyote
cactus
LSD
A synthetic drug
Marijuana
A psychoactive drug derived from the hemp
plant
MDMA or ecstasy
Synthetic club drug that combines stimulant
and mild psychedelic effects
Dissociative anesthetics
Class of drugs that reduce sensitivity to pain
and produce feelings of detachment and
dissociation; includes the club drugs
phencyclidine (PCP) and ketamine
Sigmund Freud (1856-1939)
Founder of psychoanalysis; proposed that
dream images are disguised and symbolic
expressions of unconscious wishes and
urges
Ernest R. Hilgard (1904-2001)
American psychologist who extensively
studied hynosis and advanced the
neodissociation theory of hypnosis
J. Allan Hobson (b. 1933)
Contemporary American psychiatrist and
neurobiologist who has extensively
researched sleep and dreaming; proposed
the activation-synthesis model of dreaming
William James (1842-1910)
American psychologist and philosopher who
proposed that the subjective experience of
consciousness is an ongoing stream of
mental activity