Universality of Sleep
True or False: All humans throughout history have slept?
True
As far as we know, all humans throughout history have slept
When people are asked to self-report their sleep, do they tend to overestimate or underestimate how much they sleep?
Overestimate
Slow-wave sleep is characterized by ___ waves that are slow in frequency but large in amplitude.
Delta
Delta waves (0.5-4 Hz) are a hallmark of slow-wave sleep.
The part of the brain that is often called "the Master Clock."
Suprachiasmatic nucleus (SCN)
It's in the anterior hypothalamus and uses about 20,000 neurons.
He is known as the "Father of Modern Sleep Research"
Nathaniel Kleitman
What specific adaptation do dolphins demonstrate when they sleep?
Unihemispheric sleep
How do actigraphy and sleep wearables typically detect sleep?
Accelerometry (motion or movement), photoplethysmography or PPG (pulse), and light
How many stage-to-stage changes are there each night?
around 32
5-6 full cycles each night
What molecule builds up in the brain during wake and is crucial component of sleep/wake regulation?
Adenosine
It builds up during extended wakefulness and promotes sleepiness and sleep pressure.
He was a student of Kleitman, founded the first narcolepsy clinic, founded the journal SLEEP, and developed the first undergraduate course on sleep.
William Dement
For much of human history, people believed that sleep was ____ process somewhere between wake and death.
Passive
A score above ____ on the Pittsburgh Sleep Quality Index indicates clinical poor sleep quality.
5
What discovery by Aserinsky and Kleitman dispelled the view that sleep is a unitary, passive state?
REM sleep
They discovered rapid eye movements during sleep and Dement and Kleitman connected them to dreaming and physiological changes.
Light is a ___ that entrains our biological clocks
Zeitgeber
Light and other zeitgebers are needed to entrain our biological clocks to the 24-hour nychthemeron.
He was a gentleman scientist who discovered the K-complex.
Alfred L. Loomis
This time period had a major effect on sleep, contributing to a change from segmented sleep to consolidated sleep
The Industrial Age
Sally sleeps from 2am-6am on Mondays, 10pm-7am on Tuesdays and Thursdays, 4am-8am on Wednesdays, 2am-7am on Fridays, and 12am-8am on the weekend. What term refers to the discrepancy in bedtimes and waketimes on different days?
Intraindividual variability in sleep
When people go back and forth between healthier levels of sleep and short sleep, it is termed yo-yo sleep.
Rapid eye movements co-occur with ___ waves.
Sawtooth
They are a common EEG feature during REM sleep and may play a role in cognitive processes during REM sleep.
the retinohypothalamic pathway
Retina has ganglion cells with photopigments called melanopsin that detect light. This information travels to the optic chiasm and then to the SCN, which regulates circadian rhythms.
He developed the two process model of sleep regulation.
Alexander Borbely
What five cross-species factors are associated with NREM/REM sleep?
1. Higher predation risk - leads to reduced NREM and REM sleep
2. Metabolism rate - needing to fulfill food requirements can lead to needing more sleep
3. Greater brain mass/cognition - associated with greater REM sleep
4. Longer gestational period - Associated with less REM because more time for brain to develop before birth
5. Clearing waste products from brain - total sleep duration is greater in species that need to clear more waste products
Billy loves monitoring his sleep using his Apple Watch. He is always trying to improve his sleep score and attempts to get more slow-wave sleep and REM sleep. When he gets a score lower than he would like, it is frustrating and stressful to him. What is Billy experiencing?
Orthosomnia
It is a maladaptive phenomenon where excessive preoccupation with tracking sleep leads to worse sleep.
What is the purpose of a K-complex?
To detect a stimulus and it's importance
If it is an important stimulus, then it leads to arousal.
To achieve a phase delay of the circadian system, a light stimulus must be presented ____ the temperature nadir. To achieve a phase advance of the circadian system, a light stimulus must be presented ____ the temperature nadir.
Before; After
the light must be presented before the nadir to phase delay (move later in time), and presented after the nadir to phase advance (move earlier in time)
_____ is the Greek god of sleep. His brother is ____, the god of death
Hypnos and Thanatos