# Is there any scientific data showing one can learn while sleeping?

Time is short in the days of learning for me but I like listening to lectures and case studies about code in my field. I've thought about getting a Bluetooth Sleep Headphone to possibly listen to these lectures and studies while sleeping.

However, upon my research I've only be able to find on this site one a Q&A without an answer: "Can one learn whilst sleeping? Can one solidify a memory & study for exams by listening to recordings while asleep?".

In my research and Google kungfu I've seen questionable sites that indicate as yes and some no but I was wondering have there been any creditable university case studies that show wether this is factually possible?

I don't think that it is possible to learn new facts while sleeping, but it is certainly possible to reactivate certain memories during sleep and thereby affect the probability of those memories being retained.

In one study, participants learned a visuospatial task while smelling an odour. They were better at remembering how to perform the task if they were subsequently exposed to the same odour during sleep.

Reactivating Memories during Sleep by Odors: Odor Specificity and Associated Changes in Sleep Oscillations, Julia S. Rihm, Susanne Diekelmann, Jan Born and Björn Rasch https://www.mitpressjournals.org/doi/abs/10.1162/jocn_a_

In another study, participants had to learn spatial locations for some objects and a sound associated with each object. The sounds associated with some of these objects were played back to them during sleep. Upon awakening, they were better at recalling the locations of objects whose sounds they had heard during sleep.

Strengthening Individual Memories by Reactivating Them During Sleep, John D. Rudoy, Joel L. Voss, Carmen E. Westerberg, Ken A. Paller https://science.sciencemag.org/content/326/5956/1079

In another study, participants remembered melodies better if they later heard those melodies during sleep.

Cued memory reactivation during sleep influences skill learning James W Antony, Eric W Gobel, Justin K O'Hare, Paul J Reber& Ken A Paller https://www.nature.com/articles/nn.3152

I am almost a layman but I got to learn something on the subject.

As far as I could understand, what in common can be found in wake/sleep and learning are the brain waves. Neurons exchange signals in form of electrical pulses and the collective frequency of these firing rates are indeed these brain waves. In this article it is pointed out that learning can be differentiated in explicit and implicit.

Explicit learning occurs, for example, as one is engaged in learning English grammar rules (that posted article explains more in deep the difference between explicit and implicit learning) This kind of learning is characterised by the dominance of high frequency brain waves (called alpha and beta, the latter being faster. This range is characterised by frequencies of 10-30 hertz. Hertz is a measure of frequency, defined as $$1/second$$, that is: consider for example the centrifugue of the washing machine: if it does 10 rounds in a second, then its frequency is 10 hertz).

On the other hand, when one sleeps, his/her brain wave frequency drops from alpha to theta in the pre-sleep stage and eventually to delta in the deep sleep phase. This latter is the slowest frequency of the spectrum (ranging in 1 to 4 hertz according to refer here for more).

Hence I would say that active learning as could performed during wake can not be accomplished during sleep inasmuch there is not the proper brain waves setting to, almost for what concerns explicit learning.

I hope it helps and hope I got the point correctly. Wish you best luck with your study!

• It's not really correct to say that the "brain wave frequency drops": waves of different frequencies come from different sources, delta waves aren't just "alpha waves slowed down", they originate from different patterns of activity. Additionally, power falls off with frequency as 1/f or 1/f^2 (or some other exponent), so there is pretty much always more delta than alpha for example: it's just that in sleep delta goes up and alpha goes down relative to wake. Lastly, none of these things actually say anything about the question except to say "the brain is in a different state during sleep" – Bryan Krause Jul 2 '19 at 18:53
• Thank you for your remarks, Bryan! I will dig into the subject some deeper. However, indeed the fact that the brain is in different states in terms of waves frequencies during sleep points out that some cognitive processes, such as explicit learning, may not take place whatsoever in sleep stage, is it that phrased correctly like this? – Matteo Zambra Jul 4 '19 at 11:25
• Yes I would just be careful to not make it sound like the inability to learn explicitly is caused by the change in spectrum. – Bryan Krause Jul 4 '19 at 15:36