You Can’t Learn in Your Sleep?

By: Trang Nguyen

Think about all the time you spend sleeping. Now, consider those hours spent learning instead. Of course, this is not possible. The human body requires a certain amount of sleep in order to properly function. Staying up all night to cram for a test will result in a poorer performance because of a simple and undeniable fact: sleep is a necessity. But what if the ultimatum between sleep and learning did not exist?

Hypnopedia is the “instruction of a sleeping person especially by means of recorded lessons—called also sleep-learning, sleep-teaching.” The term became popular in the mid-20th century, when several studies supposedly found evidence supporting sleep-learning. One such study was done by B.H. Fox and J.S. Robbin in 1952, looking at learning Chinese through hypnopedia. The participants of the Fox and Robbin study were divided into three groups. One group was played a recording of Chinese words and their correct English translations. A second group listened to a recording of the same Chinese words, but with incorrect English translations. The control group heard only a recording of music. A Chinese language comprehension test was administered to the study participants the next morning, and positive results were found supporting the theory of sleep-learning.

Another study that reinforced the belief in hypnopedia was done in 1942 by L. Leshan. In this study, the experimental group consisted of 20 boys between the ages of eight and 12 that had a nail biting habit. While they were sleeping, these 20 boys were played a recording of the phrase “my fingernails taste terribly bitter” a total of 300 times over the course of 54 nights. The control group of this study did not have any recording. Leshan found that 40% of the boys in the experimental group broke the habit of biting their nails after the 54 nights, supporting his hypothesis that people could be influenced in their sleep.

 The idea of hypnopedia was adapted quickly in many works of literature and pop culture. In Aldous Huxley’s Brave New World, sleep-learning was used to condition children into placidly accepting their role in a dystopian society. In one episode of the popular TV show “Friends,” one of the characters listens to a smoking-cessation audiotape while he sleeps, telling him that he is a “strong confident woman” that does not need to smoke. As a result of the recording, the character is able to stop smoking, but also begins to act like a woman.


Photo credit: umjanedoan / Foter / CC BY

Although these works of fiction make hypnopedia seem very possible, Charles Simon and William Emmons debunked the theory of sleep-learning in. The study asked 21 men a 96 question test, then played recordings with the correct question-answer combinations while the men slept. This study was conducted with the use of an electroencephalograph (EEG), allowing the researchers to measure the alpha waves of the brain to determine if the participant was truly asleep. Simon and Emmons found that any “learning” occurred while participants were awake or in a very relaxed state with their eyes closed. According to the EEG readings, when the participants were in a sleeping state, they did not learn any new information.

While sleep-learning may be a tempting idea, Simon and Emmons produced evidence that any learning happened while the mind was in a waking state. Unfortunately, that means you will not be able to memorize all your Spanish vocabulary while you sleep. On the bright side, though, you can be sure that you are safe from having your thoughts tampered with during the night.