Chapter14 Flashcards
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)
Stage 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 disrupts 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 that to fulfill some particular physiological need.
Executive function
A collection of cognitive abilities (planning, insightful thinking, and reflective 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 depravation in laboratory rats.
Circadian rhythms
Diurnal (daily) cycles of body functions
Zeitgebers
Environmental cues, such as light-dark cycles, that entrain the 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 zeitgeber 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. ( display patterns of continuous slow-wave sleep in cortical EEGs).
Desynchronized EEG
Low-amplitude, high frequency EEg.
Encephale isole preparation
An experimental preparation in which the brain is separated form the rest of the nervous system by a transection of the caudal brain stem. (displayed a normal wake-sleep cycle of cortical EEG).
Reticular activating system
The hypothetical arousal system in the reticular formation.
Hypnotic drugs
Sleep-promoting drugs.
Antihypnotic drungs
Sleep-reducing drugs.
Melatonin
A hormone that is synthesized from serotonin in the pineal gland and influences the circadian rhythm of sleep. (Higher levels associated with darkness and sleep.)
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 momentary interruptions in breathing.
Periodic limb movement disorder
Recurrent involuntary movements of the limbs during sleep; a major cause of insomnia.
Restless leg 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 the person is falling asleep or waking uo.
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.
Monophonic sleep cycles
Sleep cycles that regularly involve only one period of sleep per day, typically at night.
Sleep inertia
The unpleasant feeling go grogginess that is sometimes experienced for a few minutes after awakening.
