Sleep
20 evidence-labeled concepts on Sleep, drawn from the Shrink Atlas. Each concept is a short lesson: what it is, why it matters, how to work with it. Explore the list, or start with the one that fits your question today.
Chronotype
Your biology sets when you naturally feel alert and sleepy.
Circadian Rhythm
The circadian rhythm is your internal daily clock, tuned mostly by light.
Hypnagogia
The vivid, drifting edge between being awake and asleep.
Light Exposure
When you get light, especially bright light, tunes your sleep-wake clock.
Melatonin
The brain's night signal that prepares the body for sleep.
Nap Architecture
Nap architecture is the way a nap's length and timing determine what you actually get from it.
REM Atonia
A temporary paralysis in REM that stops you acting out dreams.
REM Rebound
Missed REM sleep gets repaid with more REM on later nights.
Restorative Sleep
Restorative sleep is rest that truly refreshes, not just hours logged.
Sleep Architecture
Sleep has a structure, cycling through stages all night long.
Sleep Debt
Sleep debt is the quiet tally of the rest you didn't get.
Sleep Efficiency
A measure of how much of your time in bed is real sleep.
Sleep Hygiene
Sleep hygiene is about creating the right conditions, not forcing rest.
Sleep Inertia
Sleep inertia is the temporary fog between being asleep and being fully awake.
Sleep Pressure
Sleep pressure is the drive to sleep that rises with every waking hour and clears when you sleep.
Sleep Spindles
Short brain bursts during sleep that help store new learning.
Slow-Wave Sleep
The deep sleep that restores the body and locks in certain memories.
Social Jetlag
A recurring clash between your inner clock and your social schedule.
Two-Process Model of Sleep
Sleep timing comes from sleep pressure and the circadian clock working together.
Wind-Down Routine
A consistent set of soothing steps that ease you toward sleep.
How this library is organized
Every concept in Sleep lives in one of six realms of the Shrink Atlas and carries an honest evidence label. This page is a navigation aid; the concept pages are where the lessons are. Follow one, or come back tomorrow for the daily concept.
See the whole Atlas · See the frameworks that use these concepts · See guided pathways