Sleep-learning (also known as hypnopædia [hip-noh-pee-dee-uh]) attempts to convey information to a sleeping person, typically by playing a sound recording to them while they sleep. This now-discredited technique was supposed to be moderately effective at making people remember direct passages or facts, word for word. Since the electroencephalography studies by Charles W. Simon and William H. Emmons in 1956, learning by sleep has not been taken seriously. The researchers concluded that learning during sleep was ‘impractical and probably impossible.’ They reported that stimulus material presented during sleep was not recalled later when the subject awoke unless alpha wave activity occurred at the same time the stimulus material was given. Since alpha activity during sleep indicates the subject is about to awake, the researchers felt that any learning occurred in a waking state.
In Aldous Huxley’s 1932 novel ‘Brave New World,’ hypnopaedia is used for the conditioning of children by future culture. In the novel, sleep-learning was discovered by accident when a Polish boy named Reuben Rabinovitch was able to recite an entire radio broadcast in English after a radio receiver was left on in his sleep. The boy was unable to comprehend what he had heard via hypnopædia, but it was soon realized that it could be used to effectively make suggestions about morality.
The Daily Omnivore 