Hypnopaedia:  Does sleep learning really work?

Wouldn’t it be nice if we could extend our learning time each day and actually learn useful information in our sleep? This is the idea behind hypnopaedia or “sleep learning”. In it, information is passed from a tape recording device to someone who is sleeping. If it works, imagine the languages you could learn in your sleep or the knowledge you need for work could be taken home and fed to your subconscious allowing for great leaps in your learning ability.

How was hypnopaedia discovered?

This is a practice that was first discovered in the 1920s, when Alois Saliger first invented the Psycho-Phone, a device that played sound while you were sleeping, feeling that sleep was a lot like being in a hypnotic trance where a person is more susceptible to suggestion and learning. This phenomenon was further studied in the 1950s, when, due to the invention of the encephalogram, which records brain wave activity, found that research subjects fed information during sleep were only able to recall the information given to them while their brains were exhibiting alpha wave activity. This is the type of brain activity one has upon awakening. The subjects, these researchers felt were not really sleeping at all but were in the wakeful state when the stimuli were given to them. Even though hypnopaedia was largely discredited at that time, recent research indicated that things like classical conditioning could be learned while asleep while using the olfactory system, with odor recognition providing a paired stimulus to a learned subject. The usefulness of this kind of learning is pretty limited and yet companies and entrepreneurs have been marketing sleep learning CDs and tapes for decades, hoping to reach audiences of overworked people trying to make something useful out of their sleeping hours.

Does hypnopaedia work?

As of today, whether hypnopaedia works or not is highly controversial, with some people saying that the most sleep teaching might be able to do is to change a certain habit, like smoking, or change their attitude about a topic. Surprisingly, there has been little scientific research available to show whether or not even conditional learning can be assimilated during sleep. People who market hypnopaedia-related tapes and CDs feel that there is more potential for sleep learning to become useful for remembering facts and data than we now believe scientifically. By using CDs during REM sleep and making use of deep brain functions such as smell and simple hearing methods, they were able to get some information passed onto the consciousness. It is similar to falling asleep to the television set only to dream about something being played on TV. Usually the information gained by “dreaming” this type of data is not the same as pure learning and is influenced by the typical subconscious ideas put forth when we dream. French researchers found in a more recent study that those who were sleeping could respond to certain words given to them during the sleep process but that it didn’t mean they had a complete understanding of what the words actually meant. The “learning” found during REM sleep did not pass through the prefrontal cortex, which is a necessary part of being able to recall things once awake. It is an interesting phenomenon that has not yet been found to have practical applications in the waking hours. This isn’t to say that we can’t do some problem-solving while in our sleep state. Studies have shown that if you are trying to solve a complex problem, whether it be a math problem or a day-to-day dilemma, you can have a better chance of solving the problem the next day if you interrupt REM sleep during the “learning process”. Thus, you cannot truly solve problems in your sleep but sleeping on a problem may be able to pave the way for people to figure out a complex problem the day after sleeping on it when hypnopaedia is employed. Strong emotions can best be processed during sleep so that those who are dealing with emotional content have a better time dealing with strong emotions when they are allowed to “dream” the feelings.

How does hypnopaedia work?

Hypnopaedia works by passing information from a tape recording device to someone who is sleeping. When this is done often enough, they are able to get some information passed onto the consciousness. One possible use of hypnopaedia is the reinforcement of learning that is initiated the night or day before, such as learning new music or sports activity. When people are taught something such as a dance movement or music lesson showed ongoing improvement when allowed to show their skills the next day, even without teaching them anything during the night. In other words, sleep could be used to reinforce memories and skills learned during the waking hours after a night’s opportunity to assimilate the memories. It is well known that sleep helps us reinforce memories and, when we don’t get enough sleep, we do not have as good a recall as we do when we have had the chance to “lay the memories” down into our cortical brain areas during sleep. This is why subjects who get enough sleep before an examination did better than those who “crammed for the test” during the night before the exam. This carries over especially in things like music. If you learn a musical score awake and then sleep on it, you can better master playing the music the next day; however, there is no evidence to suggest that playing the music to you while asleep has any impact on your ability to recall and play the music the following day. Many books and movies have popularized the idea of sleep teaching, incorporating this practice as part of the plot of the story and many people are still fascinated by the idea of learning in one’s sleep. Unfortunately, research has not caught up with this popular idea and you may not be doing anything at all by playing some complex learning theory to yourself during sleep.