Learning in your sleep
Overscheduled people often look at sleep as wasted time. If we can multi-task while we’re awake, why not while asleep? That question leads many to consider whether they can learn something while sleeping. There are businesses that sell recordings designed to play to the sleeping student in hopes of imparting knowledge, or at least a change in attitude or habits.
While the viability of these techniques is not out of the question, there has been surprisingly little scientific investigation of sleep learning.
Hypnopaedia is a fancy name for sleep learning. In the mid-20th Century serious researchers found positive results, and sleep-learning entered the popular consciousness. It was used in the dystopian novels Brave New World and Clockwork Orange.
A more positive use of sleep learning was encouraged by people who sold records designed to play while the listener was asleep. Commercially, things haven’t changed much although the recordings you find today are more likely to be digital.
Such hard evidence as we have suggests that these methods can be effective in getting people to remember rote facts. It does not appear to be effective in promoting more subtle and substantial learning. However, little recent formal scientific investigation has been done on the question.
Problem solving – Sleep on it
There is some evidence people can solve complex problems more readily if their deliberation is interrupted by sleep. Attacking a tough problem (mathematical, logical, or pragmatic day-to-day) during the day but unable to solve it, people often have better success the next day, after a night of sleep. It is not known which stage, if any, of sleep is the most productive for problem solving.
Further, there is evidence that complex designs, including those with emotional components, often go better after one or more nights of sleep. The familiar admonishment to “sleep on it” appears to be valid.
It's not just mental learning. Physical training such as practicing music, dance and sports causes people to continue to improve for at least a day following a training session. That's been known for a long time. Recent research confirms that sleep plays an important part in that continued learning.
Researchers at Northwesten University found that a 90-minute nap can help solidify learning. They tried teaching new things - both mental and physical - to people and then measured how well the new skills and knowledge stuck. Those who were told to sleep in the lab after the new experiences showed better mastery later on.
"O Sleep, rest of all things, mildest of the gods, balm of the soul..."
(Iris to Hypnos. Ovid, Metamorphoses)