Schlaf
12 cards from across every topic, each citing a source. Tap one to open it in the feed.
- About 70 percent of people know that jolt before sleep.
Roughly 70 percent of people experience a hypnic jerk at least once in their life, about 10 percent daily. The cause is …
- Caffeine doesn't give energy. It hides tiredness.
The longer you are awake, the more adenosine accumulates in your brain and binds to receptors that make you sleepy. …
- During sleep, your brain rinses itself out.
The brain tissue itself has no lymphatic vessels. Instead the brain pumps cerebrospinal fluid through the tissue and …
- How your brain decides at night what you'll keep.
During deep sleep the hippocampus replays the day's activity patterns at high speed and gradually transfers them to the …
- In dream sleep your body is almost completely paralysed.
During REM sleep motor neurons are actively inhibited: their membrane potential drops by 2 to 10 millivolts, so they …
- Why a 10-minute nap works better than 30 minutes.
In 2006 Brooks and Lack compared naps of 5, 10, 20 and 30 minutes. The 10-minute nap produced the strongest and …
- Why you perk up in the morning after an all-nighter.
The two-process model explains sleepiness as the sum of two forces. Process S is sleep pressure: it builds with every …
- You are at your latest around age 20.
Till Roenneberg analysed some 25,000 questionnaires from Germany and Switzerland. Chronotype grows later throughout …
- You cross time zones every week – without a plane.
Social jet lag, a term coined by chronobiologist Till Roenneberg, is the gap between your mid-sleep on workdays and on …
- You don't sleep one night, you sleep five short ones.
Your sleep runs in cycles of about 90 minutes, typically 4 to 6 per night. Each cycle moves from light sleep through …
- Your 4 p.m. coffee is still half there at midnight.
Caffeine blocks adenosine receptors – adenosine is the signal that builds up sleep pressure across the day. Its …
- Your eye has a sensor that only sets the clock.
Alongside rods and cones, your retina has special ganglion cells containing the pigment melanopsin. They report …