Sleep and remember
Nothing can replace a good night's sleep, especially to restore memory or stimulate the ability to learn a language, says an American study.
The benefits of sleep have long been well known. But researchers at the University of Chicago published a study in the journal Nature that shows that when we sleep, brain activity encourages higher types of learning.
"Sleep has at least two kinds of effects on learning," said Daniel Margoliash of the University of Chicago. "Sleep consolidates memories, protects them from interference or decay. Sleep also restores memories," he added.
Margolish and his colleagues tested the ability of three groups of college students to understand words created with the help of a difficult-to-understand synestheizer. They measured their ability to recognize the words and then trained them to do so. After testing the first group one hour after they were trained, 54 percent recognized the words, more than double what they recognized before the training.
The second group was trained in the morning and tested 12 hours later. Only 10 percent were better than before training. But students trained in the evening and tested the next morning, after a good night's sleep, improved their performance by 19 percent.
When students trained in the morning were tested again after sleeping, they also improved their achievements.
If performance has been reduced by an intervention, sleep can strengthen relevant associations and weaken irrelevant associations, improving access to relevant memories," the researchers said.
