In Israel’s Loewenstein Rehabilitation Hospital, the patient known as LI1 is a prisoner of her own body. She is a 51-year-old woman who was paralysed by a stroke several months ago. Suffering from “locked-in syndrome”, she is completely aware but unable to move or speak. She cannot even control the blinks of her eyes. And yet LI1 has recently been able answer questions from her doctors and communicate with her family through written messages. All she has to do is sniff.