by Matthieu Koroma, The Conversation For all sleep-learning’s promises, memorising words while awake was still five times more efficient. Credit: PaeGAG/Shutterstock From Aldous Huxley’s Brave New World to Dexter’s Laboratory cartoon series, sleep-learning has been a recurring theme in fiction. The idea that we can learn while asleep has fascinated many, but whether it is sheer fantasy or scientifically...