Why sleep should be a priorityJakke Tamminen has plenty of students who do that very studenty thing of staying up all night right before an exam, in the hope of stuffing in as much knowledge as they can. But “that’s the worst thing you can do”, the psychology lecturer at the UK’s Royal Holloway University warns them. He should know. Tamminen is an expert on how sleep affects memory, specifically the recall needed for language.