CES 2014: Revising for exams 'while asleep'
9 January 2014 Last updated at 22:43 GMT
Research into our memory patterns shows that memories that are evoked during deep sleep are more likely to stay in our minds for longer, and with greater accuracy.
Sheepdog Sciences, based in California, is seeking to use that theory to help people study.
An app logs what music or sound is being listened to while someone is learning new information. Then, at night, that audio is played back softly when a person is in deep sleep.
Sheepdog Sciences' Alex Butterwick says independent research has shown this to be a highly effective way of retaining information - meaning students can be revising for big exams, even if they are fast asleep.