Jake Tamminen from the University of York and his colleagues from Notre Dame and Harvard have found that sleep improves one’s ability to learn.
The researchers gave two groups of volunteers some nonsense words like ‘cathedruke’ to memorize. One group was given the words in the evening and then sent to bed for a polysomnographically monitored night’s sleep. The following morning, they were tested to see whether they remembered the words. The second group was given the same words in the morning, and then retested an equivalent number of hours later that day with no sleep interval. Not only did the sleep group recall more words than the wake group, but the sleep group recalled more words after sleep than they had immediately after learning the words.
The polysomnograph data revealed that ‘sleep spindles’ (intense bursts of brain activity) were firing in the brains of the sleeping volunteers. These sleep spindles are indicative of information transfer from one area of the brain to another.
According to Tamminen:
Our study identifies the brain activity during sleep that organizes new memories and makes those vital connections with existing knowledge.