Ch 11 Definitions: Sleep and Waking Flashcards
circadian rhythm
a repeating cycle of about 24 hours
ultradian cycle
a cycle that occurs several times in a single day
zeitgeber
an external cue for setting biological rhythms
free-running circadian rhythm
a rhythm that is not synchronized to environmental time cues
entrainment
the resetting of internal biological clocks to the 24-hour cycle of the earth’s rotation
shift maladaptation syndrome
a condition resulting in health, personality, mood, and interpersonal problems resulting from sleep disruption due to shift work
jet lag
fatigue, irritability, and sleepiness resulting from travel across time zones
suprachiasmatic nucleus (SCN)
an area of the hypothalamus located above the optic chiasm;
responsible for maintaining circadian rhythms
intrinsically photosensitive retinal ganglion cells (ipRGC)
retinal cells that do not process information about visual images, but rather provide light information to the suprachiasmatic nucleus
retinohypothalamic pathway
a pathway leading from the retina of the eye to the hypothalamus;
provides light information necessary for maintenance of circadian rhythms
melanopsin
a photopigment used by ipRCGs
melatonin
an indoleamine secreted by the pineal gland that participates in the regulation of circadian rhythms
cortisol
a hormone released by the adrenal glands that promotes arousal
major depressive disorder with seasonal pattern
a type of depression that results from insufficient amounts of daylight during the winter months;
formally known as seasonal affective disorder (SAD)
beta wave
a brain waveform having 14 to 30 cycles per second,
associated with high levels of alertness during wakefulness
alpha wave
a brain waveform having 8 to 13 cycles per second,
associated with less alertness and more relaxation than beta activity during wakefulness
gamma band activity
a brain waveform having more than 30 cycles per second,
associated with the processing of sensory input
theta wave
a brain waveform having 4 to 7 cycles per second
found primarily in lighter stages of NREM sleep
rapid eye movement (REM) sleep
a period of sleep characterized by desynchronous brain activity, muscle paralysis, eye movement, and storylike dream behavior
non-REM (NREM) sleep
a period of sleep characterized by slow, synchronous brain activity, reductions in heart rate, and muscle relaxation
myoclonia
a muscle jerk occurring in early stages of sleep
sleep spindle
a short burst of 12 to 14 cycle-per-second waves observed during NREM sleep
K-complex
a brief burst of brain activity consisting of single delta waves occurring during stage 2 NREM sleep
delta wave
a brain waveform having 1 to 4 cycles per second that occurs during stage 3 and 4 of NREM sleep
cholinergic mesopontine nuclei
a group of cells located at the border of the pons and midbrain that use ACh as their major neurotransmitter and participate in the maintenance of waking
‘meso’ refers to mesencephalon, or midbrain
‘pontine’ refers to the pons
default mode network (DMN)
a circuit that is active during periods of unfocused thought
sleep debt
the homeostatic control of sleep, in which sleep promotion is related to the preceding duration and intensity of wakefulness
PGO wave
an electrical waveform observed during REM sleep,
originating in the pons
and traveling to the thalamus and occipital lobe
each PGO wave is associated with an eye movement
growth hormone (GH)
a hormone released during stages 3 and 4 of slow-wave sleep that promotes growth, increases in bone and muscle mass, and immune system function
neural network model
an approach to understanding the function of dreaming as a means for forgetting irrelevant information
REM rebound
the increased amount of REM sleep following a period of REM deprivation
activation-synthesis theory
a theory suggesting that dream content reflects ongoing neural activity
evolutionary model of dreaming
a theory suggesting that dreaming provides the advantage of consolidating memories during sleep rather than during waking
threat simulation hypothesis
a theory suggesting that dreams provide practice for dealing with threats
nightmare
a REM dream with disturbing content
lucid dreaming
thoughtful dreaming;
the dreamer is aware that he or she is dreaming and can manipulate the experience
sleep terror
an NREM episode in which the individual is partially aroused, disoriented, frightened, and inconsolable
insomnia
difficulty initiating or maintaining enough sleep to feel rested
onset insomnia
insomnia in which the individual has difficulty getting to sleep at bedtime
maintenance insomnia
insomnia in which the individual cannot stay asleep during the night
narcolepsy
a sleep disorder characterized by the intrusion of REM sleep, and occasionally REM paralysis, into the waking state
cataplexy
a feature of narcolepsy in which REM muscle paralysis intrudes into the waking state
sleep paralysis
a feature of narcolepsy in which REM muscle paralysis occurs preceding of following actual sleep
hypnogogic hallucinations
a REM-type dream that intrudes into waking state prior to the onset of sleep
hypnopompic hallucinations
a REM-type dream that intrudes into waking upon awakening
hypopnea
a reduction in airflow during sleep
apnea
the total absence of airflow for a period of time
sudden infant death syndrome (SIDS)
a syndrome in which an otherwise healthy infant stops breathing and dies during sleep
sleepwalking
walking while asleep,
Usually during NREM
REM sleep behavior disorder
a sleep disorder in which the normal REM paralysis is absent
restless leg syndrome (RLS)
a sleep disorder in which a limb, usually a leg, moves at regular intervals during sleep
