The MIT scientists called it Project Inception. Their goal was to make a mouse experience a false memory, like a man who swears—and believes—he came up with an idea that Leonardo DiCaprio actually planted in his head. And they succeeded. By tracking and activating memory-related brain cells, the team made a mouse react as if it had received shocks in one place when the animal had actually experienced that pain in another. Researcher Steve Ramirez says their work could lead to more pleasurable results for humans, like erasing or ameliorating bad memories in people who suffer from depression or posttraumatic stress disorder.