Sleep, learning, and memory are very intricate psychological phenomena that to this day are not fully comprehended. However, there are quite a few studies that prove that the quantity, and more important, the quality of sleep have a huge impact on learning and memory.
Healthy sleep is essential for optimal learning and memory function. Sleep is known to aid learning and memory in at least two ways. First, it’s a well-known fact that somebody suffering from sleep deprivation is unable to focus and as a result cannot learn efficiently. Second, it is in our sleep that the cementing of memory takes place, which is essential for learning new information.
The three stages of learning
Although the exact mechanisms are still to be mapped out, learning and memory are often described in terms of three distinct functions.
- Acquisition refers to the introduction of new information into the brain.
- Consolidation represents the processes by which a memory becomes stable.
- Recall refers to the ability to access the information (whether consciously or unconsciously) once it has been stored.
Each of these steps is essential for good memory function. Acquisition and recall happen only while we are awake, but memory consolidation takes place during sleep through the strengthening of the neural connections that make up our memories.
Sleeping after a lesson cements learning
Too little sleep affects the brain’s ability to consolidate both factual information — simple facts as what you ordered for lunch or that Tolkien is the author of The Lord of the Rings trilogy — and procedural memories about how to perform different physical tasks—such as driving a car or playing the violin.
Research suggests that the most critical period of sleep for memory consolidation is the one immediately following a lesson. If this opportunity is lost, such as when the learner doesn’t get a full night’s sleep, it generally can’t be made up. Even if sleep is “recovered” on following nights, the brain will be less able to remember and employ the information gathered on the day before the all-nighter.
The science and phases of sleep
Sleep can be divided into two major phases: rapid-eye-movement (REM) and non–rapid-eye-movement (NREM) sleep.
Sleep begins with the NREM state. In turn, NREM sleep itself goes through four different stages: onset (Stage 1), light sleep (Stage 2), and deep sleep (Stages 3 and 4). After about 60 to 90 minutes, REM sleep kicks in. This only lasts for 20 to 30 minutes, and then NREM sleep returns to give way to a new sleep cycle.
During the course of a regular night, a healthy adult will go through four to six consecutive sleep cycles. NREM and REM sleep follow each other regularly.
Both are important for health, but they hold great differences. During NREM sleep, body movements still occur, but eye movements are quiet or absent. Blood flow to the brain decreases, and electroencephalograms (EEGs) show slowing of the brain’s activity. REM sleep, on the other hand, is the opposite. The body is immobile, but even though the eyelids remain closed, the eyes rapidly move in all directions. The blood pressure, heart rate, and respiratory rate also go up and down. Blood flow to the brain increases sharply, and EEGs show spiking activity.
Dreaming is most common during REM sleep, but it may also occur during the early stages of NREM sleep.
To dream is to learn
A 2010 Harvard study suggested that dreaming may reactivate and reorganize recently learned material, improving memory and boosting performance. The subjects were 99 healthy college students who agreed to avoid alcohol, caffeine, and drugs for at least 24 hours prior to the experiment. All the volunteers demonstrated normal sleep patterns before enrolling in the study.
Each of the subjects spent an hour learning how to navigate through a complex three-dimensional maze-like puzzle. After the training period, half of the students were allowed to nap for 90 minutes, while the others read or relaxed. Following a lunch break, all the volunteers tackled the virtual maze again.
The only students whose performance was substantially better were the few who dreamed about the maze during their naps. Although the dreams didn’t actually depict solutions to the puzzle, the researchers believe they show how the dreaming brain can reorganize and consolidate memories, resulting in better performance on learned tasks. And all the amazing dreams occurred early in NREM sleep.
Naps on the job – not as outrageous as it sounds
Ok, by now you may be wondering what does all this scientific stuff have to do with corporate learning. Well… everything.
Learning is universal and though businesses can’t really control how much sleep their employees get and how high the quality of that sleep is, raising awareness about the issue can’t hurt. Moreover, allowing workers to take short naps while on the job – bare with me, it’s not as outrageous as it sounds – especially after they have been involved in a learning experience can do a lot of good.
In 2008, German scientists reported that even a six-minute snooze may help improve memory. The subjects were 44 university students who were given two minutes to memorize a list of 30 words. Recall was tested an hour later, but during that hour, some of the subjects remained awake, another group napped for six minutes, and a third group took longer naps that averaged 36 minutes. The subjects who did not nap recalled an average of less than seven words; the students who napped for six minutes averaged more than eight words; and those who took longer naps averaged just over nine words.
So if your goal is to have efficient employees who learn effectively, allowing them time to nap might be a very inexpensive and motivating way to achieve that.
Raluca Cristescu is a Faculty of Letters graduate with over ten years of experience in corporate training, focused mainly on soft skills for customer service and direct sales.