When I was studying for my 4h Ethical hacker exam a while ago I was wondering if I could use the time I was asleep to revise the material or even learn something new.
So can you learn while you sleep? You can not learn new things in your sleep but studies have shown that you can improve your memory of something you have already learned. This enhancement can be triggered by repeating the material or with clues like sounds or smell.
So how exactly does this memory improvement work and what are the clues and types of material you can actually learn while sleeping?
How does sleep memory enhancement work?
I still remember the ads for “Learn Italian overnight” when I was looking for a language course and I always thought that was a scam. And while it is true that you cannot learn new words during the night a study where German participants were exposed to dutch vocabulary while they were sleeping has shown that they could recall the material much better than the group without the nightly lesson. You can find all the scientific details here. Another study where participants were asked to remember musical tunes showed a similar effect. The ones that listened to the same tune during a 90-minute nap after learning it could replay it much better. Scientists had analyzed the brain waves during these experiments and could establish a connection between playing the learned material and memory formation. They showed that the brain activated previously studied information when it was repeated while the participants were sleeping.
What are the practical applications of these findings?
Further research has proven that also odors can be used as cues to spark your sleeping brain. This test was conducted by combining the location of an object with a certain odor. This scent was then “replayed” during the night and people who had been subjected to a specific smell were much better at remembering where certain things were. This method is of course very impractical to practice at home and I could not find any device or gadget that would allow you to do this kind of sleep training.
Musical cues or repeating entire audio lessons are much easier to realize at home and I will certainly give it a try. There are two major problems of self-sleep-teaching.
- Researchers have shown that certain sleep phases like the non-REM (Rapid Eye Movement) are crucial for memory consolidation. I could not find any app or sleep-tracker that was able to play a sound file when detecting non-REM sleep. An article about the science of sleep-trackers even doubted that they can detect the different sleep phases at all. This makes it different for you to find the right time to play the lessons you want to repeat during your sleep which brings us to the second problem.
- To solve the problem of not knowing when it is most effective to playback the study material is to repeat it during the whole night. This would, of course, disturb your partner and earplugs are not really a comfortable alternative. I also believe that listening to something during the whole night will do more harm than it benefits your memory improvement. Since your brain is constantly bombarded with “noise” your sleep quality will certainly be affected which makes it much harder the next day to continue your study and learn new things.
I believe that future devices will be able to detect the best moment during the night to repeat study material so that you can commit it more effectively to memory. This might be a perfect business idea for you if you are in the device development business. You are welcome. So the only solution I see for now is to randomly play the audio while you are asleep (which might disturb your partner) or use it to “tuck you in”.
Sleep learning self-experiment
I am currently learning Italian so I though I give it a try. My wife agreed to endure this so I started to play audio randomly during the night. I discovered that I sometimes (but not always) I woke up when the sound started to play. That was very unpleasant so this was not for me and disturbed my sleep more than it helped.
Then I tried to fall asleep with the vocabulary of the day and played it for around 30 minutes after going to bed. Though I have the impression that I indeed could remember some of those better this method has 2 disadvantages that let me end this experiment after a while. First I could not fall asleep because I was somehow actively participating in the revision. Second I needed to prepare those audio files every night which probably took the same amount of time as repeating it the next day to keep it in my memory.
So, in conclusion, I would say this way of learning is not practical (yet) to get the most out of it. I am sure one of the big players in the wearables industry will come up with a solution and I will be the first to buy one. Apart from that, it is much more important to have high-quality sleep. I practice the simple rules of sleep improvement (Read my article about it) which dramatically improved my sleep quality. I need to sleep less which basically gives me the time to study more if I have to.
Learning through osmosis
I am not really sure how anyone could believe that but there are quite some articles about this. This suggests that you can learn something by just sleeping with your study material or be close to people like your teacher who possess the information you require. Just so you know – that is total nonsense but I guess you knew already.
Do sleep learning Apps work?
From all I have learned so far I confidently can say: No, the don’t work. Basically, these are only audio players that call themselves sleep app. If there were a way they can track when to play the audio that might be a different story and I would certainly want to try one. Until then – save
Can you learn Japanese in your sleep? I found this question and the answer was: “Yes, you know the new words in the morning like magic – if you buy this course”. From what I have found in my research this is nonsense so don’t buy anything like that. There is no shortcut to learning a language except practice!
What is sleep-learning called? Sleep learning is called Hypnopedia and was surprisingly first recorded in Aldous Huxley’s novel Brave New World (1932). It is a combination of the Greek word for sleep Hypnos (like also found in Hypnosis) and the Greek word for “child-rearing, education” paideia.
Can you smell in your sleep? The simple answer is yes. The test I mentioned above used this cue to enforce the formation of memory.
Is it ok to sleep with earplugs? Besides the fact that sleeping with earplugs (especially with cables) is very uncomfortable it comes with 2 more major disadvantages. First, your hearing is impaired so if a fire alarm goes off you might not hear it. Second due to the constant input your brain gets it will not have the rest it needs to be fully recovered in the morning.