Sleep is not only helpful in learning a new piece of information but also gets the brain to file the information away so it is available when required, according to a new study by researchers at the University of York and Harvard Medical School.
It was found by the involved scientists that sleep helps individuals to remember a newly learned word and incorporate new vocabulary into their “mental lexicon“.
During the study, researchers taught volunteers new words in the evening, followed by an immediate test. The volunteers slept overnight in the laboratory while their brain activity was recorded using an electroencephalogram, or EEG.
A test the following morning revealed that they could remember more words than they did immediately after learning them, and they could recognize them faster demonstrating that sleep had strengthened the new memories.
This did not occur in a control group of volunteers who were trained in the morning and re-tested in the evening, with no sleep in between.
An examination of the sleep volunteers’ brainwaves showed that deep sleep (slow-wave sleep) rather than rapid eye movement (REM) sleep or light sleep helped in strengthening the new memories.
When the researchers examined whether the new words had been integrated with existing knowledge in the mental lexicon, they discovered the involvement of a different type of activity in the sleeping brain.
The study has been published in the Journal of Neuroscience.