Individual differences in circadian activity.
Disorder of slow-wave sleep resulting in prolonged inability to sleep.
Environmental event that entrains biological rhythms: a 'time giver.'
Slow-wave sleep disorder in which a person uncontrollably falls asleep at inappropriate times.
reticular activating system (RAS)
Large reticulum (mixture of cell nuclei and nerve fibers) that runs through the center of the brainstem; associated with sleep-wake behavior and behavioral arousal; often called the reticular formation.
medial pontine reticular formation (MPRF)
Nucleus in the pons participating in REM sleep.
Brief burst of EEG activity typically occurring during NREM sleep.
Two proteins combined into one.
Cholinergic nucleus in the dorsal brainstem having a role in REM sleep behaviors; projects to medial pontine reticulum.
Hormone secreted by the pineal gland during the dark phase of the day-night cycle; influences daily and seasonal biorhythms.
Combination of medical disorders, including obesity and insulin abnormalities, that collectively increase the risk of developing cardiovascular disease and diabetes.
NREM (non-REM) sleep
Slow-wave sleep associated with delta rhythms.
Brief period of sleep lasting a second or so.
Inability to move during deep sleep owing to the brain's inhibition of motor neurons.
Inherent timing mechanism that controls or initiates various biological processes.
Organism that is active chiefly during daylight.
Exposure to artifical light that changes activity patterns and so distrupts circadian rhythms.
The process of restabilizing a memory trace after the memory is revisited.
Neural route formed by axons of photosensitive retinal ganglion cells from the retina to the suprachiasmatic nucleus; allows light to entrain the rhythmic activity of the SCN.
basic rest-activity cycle (BRAC)
Recurring cycle of temporal packets, about 90-minute periods in humans, during which an animal's level of arousal waxes and wanes.
delta (d) rhythm
Slow brain-wave activity pattern associated with deep sleep.
Fatigue and disorientation resulting from rapid travel through time zones and exposure to a changed light-dark cycle.
Hippocampal neurons maximally responsive to specific locations in the world.
Time required to complete a cycle of activity.
Determine or modify the period of a biorhythm.
Rhythm of the body's own devising in the absence of all external cues.
Dreamlike event at the beginning of sleep or while a person is in a state of cataplexy.
beta (b) rhythm
Fast brain-wave activity pattern associated with a waking EEG.
Form of narcolepsy linked to strong emotional stimulation in which an animal loses all muscle activity or tone, as if in REM sleep, while awake.
Neural system that times behavior.
Condition resulting from continuous use of 'sleeping pills'; drug tolerance also results in deprivation of either REM or NREM sleep, leading the user to increase the drug dosage.
Prolonged state of deep unconsciousness resembling sleep.
Fast brain-wave pattern displayed by the neocortical EEG record during sleep.
The process of stabilizing a memory trace after learning.
suprachiasmatic nucleus (SCN)
Master biological clock, located in the hypothalmus just above the optic chiasm.
Inability to breathe during sleep; person has to wake up to breathe.
No tone; condition of complete muscle inactivity produced by the inhibition of motor neurons.
Sharp, high-amplitude EEG wave occurring during NREM sleep.