A couple of years ago, in the midst of midterms and high anxiety, I ranted to a friend about how stressed I was for my exams. My friend quickly suggested I listen to recordings of the vocabulary words and information I needed to know while I was sleeping. Naturally, I assumed she was joking, because I never heard of such a thing, and didn’t think much of her suggestion. For some reason though, whenever I am stressed about a test, I always think back to her suggestion. Can listening to information while asleep really help me learn it? It seemed too good to be true, so I decided to finally research more about it.
According to a recent study, 16 participants were taught how to play two songs on a keyboard. After the participants learned the two songs, they were then put into a dark room, where they took an hour and a half long nap. During the participant’s deepest part of sleep, they were played only one of the songs they learned on repeat. After their naps, the participants were then asked to play both songs. Notably, the participants performed better on the song that was played for them while sleeping, than the song that wasn’t played for them. As a psychologist at Northwestern noted, it is important to note though, that this study found that your memory can be strengthened while sleeping, and did not test if you are able to learn new information while asleep (Stromberg 2012).
Although the previous study did not test if new information can be memorized during sleep, a study conducted by Swiss researchers did test this. This study consisted of two groups of Germans who were all given Dutch vocabulary words to memorize. One group was then told to go to sleep, and the other to stay awake. Over the next 4 hours, the participants in both of the groups listened to audio of the vocabulary words they were given, plus new vocabulary they were not previously exposed to. After the 4 hours were up, the participants in both groups were tested on how much vocabulary they could remember. It was found that the group who slept were able to recall more of the words they were given to memorize than the group who did not sleep. Although the group who slept recalled more words they were already given, it is important to note that the words they were not given to memorize, and only heard in their sleep, were not remembered when they woke up. Here it is clear that listening to information previously learned gets enforced during sleep, but new information is not able to be recalled.
Now that we can conclude that information previously learned can be enforced during sleep, but new information can’t be learned, we can ask why that is. Although scientists are not completely aware of why this happens, their hypothesis is that during deep sleep, our mind reviews events that happened during the day, so therefore those memories can be greater enhanced when listening to them again during deep sleep. Nonetheless, with finals coming up, this technique may be a helpful study tip, but only if you’ve been going to class all along.
I’ve been thinking about the best way to get my studying done since finals are so soon, and this post was really interesting! I found Make this article which talks about if you should study for an extra hour, or just go to sleep. Basically, we need sleep in order to do well on tests the next day, but we also need to be studying over a longer period of time rather than the night before. Cramming isn’t as good because it doesn’t stick in your brain for as long as a time.
This was a very interesting post, and makes me wish we were able to talk about sleep in class all the more. I was reminded very much of the book Brave New World by Aldous Huxley while reading this post, in which civilians are brainwashed from birth in their sleep to act in patterns that correlate to their designated social class. If the German study you found is correct, this would seem impossible, unless the people are made to memorize their status constraints during the day as well. Personally, I’m not sure I find one study a convincing enough example that listening to recordings during sleep helps memorization. There are so many things unanswered about sleep that I’m not sure this should be the place to start for understanding it.
Here’s an example of the “sleep-teaching” seen in A Brave New World.
Now here’s a reason to nap a lot! The justification I finally needed to hit the sheets even more than I do already, which will be difficult. Now on a more serious note, the process that you talked about in the second study is called consolidation. According to the link below from Harvard Medical School, memories from the day are affirmed at night during consolidation because our brains our still working while we sleep, which I found quite interesting. There are two other processes in learning that both occur during the day, as far as scientists know, but consolidation is the middle step. Take a look for yourself and see what you think!
http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/learning-memory