I think I know the answer to this, but I figured it wouldnât hurt asking here.
My friend found some videos on youtube called Learning Japanese While Sleeping and wanted to know if itâd have any effect
I know these have sort of existed in many forms since the 90âs at least
and Iâm quite skeptical
but Iâm curious to know your thoughts on this method
No, it doesnât work. If anything itâll affect your sleep and have the opposite effect.
From Wikipedia, sleep learning have been proven not possible by scientists. Would have been great 
Drats, thatâs 100% of my studying time out of the window 
Oh my god how do those videos have millions of views. People will deadass watch anything huh
Theyâre usually ok-ish to watch them while youâre awake.
While listening to things while trying to sleep doesnât work, youâre brain IS in fact learning while you sleep normally.
So, doing a bit of reviewing or reading Japanese before falling asleep means youâre brain is then working and processing what youâve learnt during the day.
A good nights sleep is therefore very important to learning in general. Sleep deprivation has a huge effect on your ability to absorb new information and learn.
So to help your learning endeavors, try to find more restful ways to sleep (if you struggle to stay asleep during the night), and that should help you in general. 
At best, it might reinforce some stuff youâve been learning. You spend the day learning a vocab list of body parts, then go to sleep listening to that list. perhaps your brain will subconsciously start thinking about those words as you fall asleep and work them into a dream? Doubt it, but thatâs about the only way I can think of to try and claim sleep learning works.
