Deep Sleep Easily Strengthens Memories

A study that was published November 2, 2010 in the Journal of Neuroscience suggests if we want to learn a new word to sleep easy on it. Deep sleep easily strengthens memories of new words by a process that integrates the word into our vocabulary, changes the memory representation by making the word recognizable and easier to recall in the future. The study also implies that reading or studying for a test later in the day is more effective because our brains use the “downtime” of sleep to integrate what has been learned.

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Since research has found a link between sleep and memory a short nap can actually improve our creativity and our learning capabilities. A power nap of 15 to 20 minute can refresh and reenergize the body but sleep is just as important to our mind. The duration of a sleeping period and the quality of the sleep, or sleep intensity helps the brain to process memories. A study of English speaking college students were shown a list of Chinese words, then half of the students took a nap in which some were allowed to go into deep sleep but not REM or dream sleep. When they woke up they took a test of Chinese words and the students who napped for 90 minutes did much better on the test than the other students who slept less or the non-nappers.

Other research compiled by the University of California reported in the November issue of Behavioral Brain Research, suggests that napping after a lesson is better for you than loading up on caffeine. Caffeine may enhance alertness and concentration, but it can actually impair motor learning and verbal memory and daytime naps benefit both alertness and memory. A test was done on 61 participants that trained during the morning on memory, motor and perceptual learning skills. After lunch one group napped (60-90 minutes) while the other two groups both listened to a book on tape and received a pill with caffeine or a placebo. Later in the afternoon, all three groups were tested to see how well they had learned their tasks. The group that napped performed better on motor task and recalling words, than the caffeine group. The nap group also did much better than the other groups on perceptual learning skills. The placebo group did better than the caffeine group on all three tasks. Just thinking about the pill they took might contain caffeine (the placebo effect) helped as much as taking a nap on the motor task.

The evidence proposed that caffeine interferes with skills that require processing like recalling words verses remembering how to ride a bike. So what does this mean? Such an impairment of execution is the opposite of what society’s assumption that caffeine benefits cognitive performance and that no medicinal alternative is as beneficial as a good night’s rest or a nap in the afternoon.

Taking a nap during the work day has shown to increase alertness and productivity. Despite what research has shown employers have been reluctant to allow employees to take a nap on the job. China, India, Italy, Greece, North Africa and Latin America have been napping in the afternoon for ages and found that a quick 30 – 40 minute nap after lunch was necessary to refresh and reenergize their employees. Many foods contain tryptophan an amino acid that causes drowsiness and now scientific research has proven that a short nap will improve alertness and mood.

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In fact, big corporation like Nike and Google not only have employee perks like gyms and child care they also have quiet rooms and napping pods for employees to nap or meditate. Other smaller companies are kicking the coffee break and now allowing their employees to grab some shuteye. Napping on the job sounds strange but with all the emphasis on health and wellbeing it makes sense. Do you think it makes sense or should everyone just follow a stricter bedtime routine?

Note: A power nap is designed to prevent the napper from sleeping so long that they enter a normal sleep cycle. Entering a normal sleep cycle (30 minutes more or less) but failing to complete it can result in sleep inertia. Sleep inertia is where one feels groggy, disoriented and even sleepier than before napping. If you want to take a power nap to reenergize it is critical that you limit your time to 20 minutes. When you lay down to sleep your first sleep cycle runs about 120 minutes. The above research suggests if you want to recall a word or improve memory functions you must enter into the deep sleep cycle or slow wave sleep and you should complete your deep sleep cycle to avoid sleep inertia which is napping or even sleeping at night in 90 minute intervals.

Whether at work or at home the best time to take a nap is in the middle of the afternoon usually between 1pm and 4pm.. This is when the body is usually fighting sleep and a nap at this time has the most benefit on the body’s natural clock, so it is less likely to disrupt your night’s sleep. The content provided in Deep Sleep Easily Strengthens Memories is for information purposes only, intended to raise the awareness of different solutions for your sleep problems and should not be considered medical advice. For medical diagnosis and treatment, please see your qualified health-care professional.