The voices of some of literature’s more memorable characters have a way of staying with you, long after their stories are over. Many readers — every reader? — could’ve told you that. For some people, though, this idea is a little more literal. According to a new (and truly delightful) psychology study — published in the March edition of the journal Cognition and Consciousness — about a fifth of readers “hear” the voices of fictional characters in their heads, long after they’ve closed the books.