Have you noticed what happens when you are almost ready to fall asleep but you are suddenly jerked, soaked in cold sweat and trying to know what happened?
Apparently, thanks to the brain for taking good care of you.
Because the sudden jolt you feel is a ‘hypnic jerk’ and it’s known to serve two possible functions.
First being safety:
The jerk evaluates the environment before going to sleep, ensuring its safe before shutting your eyes.
Professor of Sleep Science explains why it must have helped our ancestors:
…to check the stability of our body position before we went to sleep, especially if we started to fall asleep in a tree.
The jerk would allow us to test our “footing” before unconsciousness set in.
‘Hypnic jerks’ remain somewhat of a puzzle, with further research required, but it is thought by Professor Ellis factors that could make them worse are: caffeine before bed, vigorous exercise before bed, or high levels of stress and anxiety.