What Is Sleep Learning?It's important to be clear about what we mean by sleep learning. After all, we all learn in our sleep. Some people have theorised that absorbing and analysing the day's events is one of the main psychological reasons for sleep.
"Sleep learning" is something much more specific. The term refers to learning new information whilst asleep rather than consolidating the day's input. Using the night time hours like this is intended to result in accelerated learning as you learn while you sleep. There are also theories that the sleeping brain is more receptive to new material.
The most common approaches to sleep learning involve audio recordings. These gently repeat certain information or affirmations during the course of the night. Some of these tapes/CDs on the market contain simple statements, others include hypnotic inductions. Some recordings also include music or binaural beats, others have the information encoded subliminally.
The most common applications are learning languages and breaking bad habits. In the latter case sleep learning is often associated with self-hypnosis.
Does Sleep Learning Work?The idea of sleep learning is far from new. One of the earliest references in literature comes in Hugo Gernsback's 1911 novel Ralph 124C 41+: A Romance of the Year 2660. This describes a "Hypnobioscope" that implants electrical signals directly into the brain of the sleeper.
Despite this there has been relatively little scientific research done on the subject. What has been done tends to be inconclusive. Earlier research seemed to show a correlation between nighttime learning products and accelerated learning. The current scientific fashion appears to be to reject sleep learning.
Anecdotal evidence also varies considerably. Some people claim it does no good, others use it frequently and report great results.
Some of these differences might be due to the exact nature of the sleep learning approach used - there are many different materials and techniques available, along with different products to buy. The things that work for one person might not work for another. Other factors might also come into play such as the stages of sleep at which the recording is played. In addition, terms such as 'accelerated learning' and super learning' are difficult to define and judge objectively so any data is likely to be clouded.
As with all these things, what matters is whether or not it works for you. The only way you'll know that is to try it for yourself.