Chapter 14 - Sleep Flashcards
The three standard psychophysiological bases for defining stages of sleep.
Electroencephalogram (EEG), electrooculogram (EOG), and electromyogram (EMG).
First-night phenomenon
The disturbance of sleep observed during the first night in a sleep laboratory. Often fitful. Because of this, usual practice is to have participants sleep several night in laboratory before commencing sleep study.
Alpha waves
8- to 12-Hz EEG waves.
K complex
A single large negative wave (upward deflection) followed immediately by a single large positive wave (downward deflection).
Sleep spindle
A 1- to 2-second waxing and waning burst of 12- 14-Hz waves.
Delta waves
The largest and slowest EEG waves, with a frequency of 1 to 2 Hz.
Stage 3 of sleep EEG
Defined by the occasional presence of delta waves.
Stage 4 EEG sleep
Defined by a predominance of delta waves.
Each sleep cycle tends to be about _______ long.
90 minutes
Once sleepers reach stage 4 EEG sleep, they stay there for a time, and then retreat back through the stages of sleep to stage ____.
1
The first period of stage 1 EEG during a night’s sleep (called ______) is not marked by any striking electromyographic or electrooculographic changes, whereas subsequent periods of stage 1 sleep EEG (called ______) are accompanied by ______ and by a ________ of the body core.
Initial stage 1 EEG,
Emergent stage 1 EEG,
REMs,
loss of tone in the muscles.
After the eyes are shut and a person prepares to go to sleep, ______ begin to punctuate the low-voltage, high frequency waves of alert wakefulness.
Alpha waves
The stage _____ sleep EEG is a low-voltage, high frequency signal that is similar to, but slower than, that of alert wakefulness.
1
The two kinds of theories proposed for sleep:
- Recuperation
- Adaptation
Recuperation theories of sleep
Being awake disrupts the homeostasis of the body in some way and sleep is required to restore it.
Homeostasis
Internal physiological stability
Adaptation theories of sleep
Sleep is not a reaction to the disruptive effects of being awake, but the result of an internal 24-hour timing mechanism– that is, we humans are programmed to sleep at night regardless of what happens to us during the day. According to these theories, we have evolved to sleep at night because sleep protects us from accident and predation during the night.
Adaptation theories of sleep focus more on _____ we sleep rather than on the _____ of sleep.
when,
function.
Even moderate amount of sleep deprivation have been found to have three consistent effects:
- increased sleepiness.
- display negative affect on various written mood tests (grumpier).
- perform poorly on tests of vigilance, such as watching a computer screen and responding when a moving light flickers.
Executive function
Innovative thinking, lateral thinking, insightful thinking, assimilating new information to update plans and strategies. Cognitive abilities that appear to depend on the prefrontal cortex.
Microsleeps
Brief periods of sleep, typically about 2 or 3 seconds long, during which eyelids droop and the volunteers become less responsive to external stimuli, even though they remain sitting or standing.
Many early studies of the effect of sleep deprivation on cognitive function used tests of _______ or ______, and performance on these has proved to be largely immune to the disruptive effects of sleep loss.
Logical deduction,
Critical thinking.
The carousel apparatus kills rats after approximately 12 days of keeping the rats from sleeping. Another explanation for their death could be _______.
Stress
REM-sleep deprivation has shown to have two consistent effects:
- participants display a REM rebound (they have more than their usual amount of REM sleep for the first two or three nights).
- with each successive night of REM deprivation, there is a greater tendency for participants to initiate REM sequences.
Default theory (pg. 351)
According to this theory, it is difficult to stay continuously in NREM sleep, so the brain periodically switches to one of two other states. If there are any immediate bodily needs, then the brain switches to awake. If not, then it goes to REM sleep.
Individuals who are deprived of sleep become more ______ sleepers. Their sleep has a higher portion of ________, which seems to be the main restorative function.
Efficient,
Slow-wave sleep (stages 3 and 4).
Which is more difficult, a phase advance or a phase delay?
Phase advance.
It is much more difficult to go to sleep 4 hours earlier and wake up 4 hours earlier (phase advance) than it is to go to sleep 4 hours later and wake up 4 hours later (phase delay).
______ means lasting about one day.
Circadian
Free-running rhythms are those that occur in environments devoid of ________.
Zeitgebers
Zeitgeber (ZITE-gay-ber)
Environmental cues, such as the light-dark cycle, that entrain circadian rhythms.
Free-running rhythms
Circadian rhythms that do not depend on environmental cues to keep them on a regular schedule.
Free-running period
The duration of one cycle of a free-running rhythm.
The major circadian clock seems to be located in the _______ nuclei of the hypothalamus.
Suprachiasmatic
The ______ tracts conduct information about light-dark cycles to the circadian clock in the SCN.
Retinohypothalamic
The first mammalian circadian gene to have its structure characterized was ________.
Clock
Patients with damage to the _________ hypothalamus and adjacent basal ganglia often have trouble sleeping.
Anterior
Damage to the ________ hypothalamus and adjacent areas of the midbrain often cause excessive sleepiness.
Posterior
The low-amplitude high-frequency EEG of wakefulness is said to be ________.
desynchronized
In Bremer’s classic study, the ________ preparation displayed an EEG characteristic of continuous sleep.
Encéphale isolé
The indices of R.E.M. Sleep are controlled by a variety of nuclei located in the caudel _______.
reticular formation.
Most drugs that influence sleep fall into two different classes:
- Hypnotic
- Antihypnotic
A third class of sleep-influencing drugs comprises those that influence its circadian rhythmicity; the main drug of this class is ________.
melatonin
Melatonin is a hormone synthesized from the neurotransmitter ___________ in the __________.
Serotonin,
Pineal gland.
Dreaming appears to occur mainly during
REM sleep
A condition in which a person’s sleep is repeatedly disrupted by the inability to breathe is called
sleep apnea
According to the study by Fichten and colleagues, he difference between long sleepers and short sleepers is
only in the amount of sleep they get–there are no other differences.
The most influential circadian zeitgeber is
light-dark cycle
Electrical stimulation of the ______ awakens sleeping cats.
reticular formation
Which of the following are commonly prescribed as hypnotics?
benzodiazepines
The 8-to-12 Hz EEG waves that are often associated with relaxed wakefulness are
alpha waves
According to the text, which theory of sleep does the best job of explaining why there are such large differences in the amount of time that the members of various mammalian species spend sleeping?
Adaptation theory
When they fall asleep, narcoleptics immediately
go into REM sleep
Free-running periods are usually longer than _____.
24 hours.
Stage 4 sleep EEG is characterized by a predominance of ______ waves.
delta
______ stage 1 EEG is accompanied by neither REM nor loss of core-muscle tone.
Initial
Dreaming occurs predominantly during ______ sleep.
REM
The modern alternative to Freud’s theory of dreaming is Hobson’s ______ theory.
activation-synthesis
There are two fundamentally different kinds of theories of sleep: recuperation theories and ______ theories.
adaptation
The effects of sleep deprivation are often difficult to study because they are often confounded by ______.
stress
Convincing evidence that REM-sleep deprivation does not produce severe memory problems comes from the study of patients taking certain ______ drugs.
antidepressant
After a lengthy period of sleep deprivation (e.g., several days), a person’s first night of sleep is only slightly longer than usual, but it contains a much higher proportion of ______ waves.
slow (or delta)
______ sleep in particular, rather than sleep in general, appears to play the major restorative role.
Slow-wave (or stage 3 and 4)
Electroencephalogram (EEG)
A measure of the gross electrical activity of the brain, commonly recorded through scalp electrodes.
Electrooculogram (EOG)
A measure of eye movement.
Electromyogram (EMG)
A measure of the electrical activity of muscles.
Alpha waves
Regular, 8-to-12 per-second, high-amplitude EEG waves that typically occur during relaxed wakefulness and just before falling asleep.
Delta waves
The largest and slowest EEG waves.
Initial stage 1 EEG
The period of the stage 1 EEG that occurs at the onset of sleep; it is not associated with REM.
Emergent stage 1 EEG
All periods of stage 1 sleep EEG except initial stage 1; each is associated with REMs.
REM sleep
The stage of sleep characterized by rapid eye movements, loss of core muscle tone, and emergent stage 1 EEG.
Slow-wave sleep (SWS)
Stages 3 and 4 of sleep, which are characterized by the largest and slowest EEG waves.
Activation-synthesis theory
The theory that dream content reflects the cerebral cortex’s inherent tendency to make sense of, and give form to, the random signals it receives from the brain stem during REM sleep.
Recuperation theories of sleep
Theories based on the premise that being awake disturbs the body’s homeostasis and the function of sleep is to restore it.
Adaptation theories of sleep
Theories of sleep based on the premise that sleep evolved to protect organisms from predation and accidents and to conserve their energy, rather than to fulfill some particular physiological need.
Executive function
A collection of cognitive abilities (e.g., planning, insightful thinking, and reference memory) that appear to depend on the prefrontal cortex.
Microsleeps
Brief periods of sleep that occur in sleep-deprived subjects while they remain sitting or standing.
Carousel apparatus
An apparatus used to study the effects of sleep deprivation in laboratory rats.
Circadian rhythms
Diurnal (daily) cycles of body functions.
Zeitgebers
Environmental cues, such as the light-dark cycle, that entrain circadian rhythms.
Free-running rhythms
Circadian rhythms that do not depend on environmental cues to keep them on a regular schedule.
Free-running period
The duration of one cycle of a free-running rhythm.
Internal desynchronization
The cycling on different schedules of the free-running circadian rhythms of two different processes.
Jet lag
The adverse effects on body function of the acceleration of zeitgebers during east-bound flights or their deceleration during west-bound flights.
Circadian clock
An internal timing mechanism that is capable of maintaining daily cycles of physiological functions, even when there are no temporal cues from the environment.
Suprachiasmatic nuclei (SCN)
Nuclei of the medial hypothalamus that control the circadian cycles of various body functions.
Melanopsin
Photopigment found in retinal cells that respond to changes in background illumination and play a role in synchronizing circadian rhythms.
Tau
The first circadian gene to be identified in mammals.
Cerveau isole preparation
An experimental preparation in which the forebrain is disconnected from the rest of the brain by a midcollicular transection.
Desynchronized EEG
Low-amplitude, high-frequency EEG.
Encephale isole preperation
An experimental preparation in which the brain is separated from the rest of the nervous system by a transection of the caudal brain stem.
Reticular activating system
The hypothetical arousal system in the reticular formation.
Hypnotic drugs
Sleep-promoting drugs.
Antihypnotic drugs
Sleep-reducing drugs.
Melatonin
A hormone that is synthesized from serotonin in the pineal gland and influences the circadian rhythm of sleep.
Benzodiazepines
A class of GABA agonists with anxiolytic, sedative, and anticonvulsant properties; drugs such as chlodiazepoxide (Librium) and diazepam (Valium).
5-Hydroxytryptophan (5-HTP)
The precursor of serotonin.
Pineal gland
The endocrine gland that is the human body’s sole source of melatonin.
Chronobiotic
A substance that influences the timing of internal biological rhythms.
Insomnia
Disorders of initiating and maintaining sleep.
Hypersomnia
Disorders characterized by excessive sleep or sleepiness.
Iatrogenic
Physician-created.
Sleep apnea
A condition in which sleep is repeatedly disturbed by momentary interruptions in breathing.
Periodic limb movement disorder
Recurrent involuntary movements of the limbs during sleep; a major cause of insomnia.
Restless legs syndrome
Tension or uneasiness in the legs that is particularly prevalent at bedtime and is a major cause of insomnia.
Narcolepsy
A disorder in the hypersomnia category that is characterized by repeated, brief daytime sleep attacks and cataplexy.
Cataplexy
A disorder that is characterized by recurring losses of muscle tone during wakefulness and is often seen in cases of narcolepsy.
Sleep paralysis
A sleep disorder characterized by the inability to move (paralysis) just as a person is falling asleep or waking up.
Hypnagogic hallucinations
Dreamlike experiences that occur during wakefulness.
Orexin
A neuropeptide that has been implicated in narcolepsy in dogs and in knockout mice.
Nucleus magnocellularis
The nucleus of the caudal reticular formation that promotes relaxation of the core muscles during REM sleep and during cataplectic attacks.
Polyphasic sleep cycles
Sleep cycles that regularly involve more than one period of sleep per day.
Monophasic sleep cycles
Sleep cycles that regularly involve only one period of sleep per day, typically at night.
Sleep inertia
The unpleasant feeling of grogginess that is sometimes experienced for a few minutes after awakening.
The activation synthesis theory (Hobson) essentially made three key assumptions:
- High levels of activity in the brainstem are necessary for dreaming to take place.
- Activation in these areas of the brain results in REM sleep and dreaming and that all dreaming takes place during REM sleep.
- The forebrain attempts to place meaning on the random signals created from the activation of the brainstem, resulting in coherent dreams.
