On the surface of it, the timing of falling asleep seems fairly easy to understand. Once you have been awake for a certain period of time, you become tired and eventually go to sleep.
A recent study published in Frontiers in Human Neuroscience suggests
Sleep is not a state of nothingness. Rather, falling asleep and staying asleep is an active process.
Like a healthy diet and sufficient exercise, restorative sleep is a fundamental pillar of health.
Why do we feel sleepy at night? What exactly tells us when to fall asleep and when to wake up? It's not just the light or warmth of the sun, for we can feel sleepy even if we are kept in a windowless office.
We’ve all heard that it is important to get “deep REM sleep” for peak performance. This is nonsense.