Steve Ramirez, a 24-year-old doctoral student at the time, placed the mouse in a small metal box with a black plastic floor. Instead of curiously sniffing around, though, the animal instantly froze in terror, recalling the experience of receiving a foot shock in that same box. It was a textbook fear response, and if anything, the mouse’s posture was more rigid than Ramirez had expected. Its memory of the trauma must have been quite vivid.
Which was amazing, because the memory was bogus: The mouse had never received an electric shock in that box. Rather, it was reacting to a false memory that Ramirez and his MIT colleague Xu Liu had planted in its brain.
The observation culminated more than two years of a long-shot research effort and supported an extraordinary hypothesis: Not only was it possible to identify brain cells involved in the encoding of a single memory, but those specific cells could be manipulated to create a whole new “memory” of an event that never happened.
What about the ethical concerns of memory manipulation? Patricia Churchland, a professor at UC San Diego and author of Touching a Nerve: The Self as Brain, says therapy of this sort won’t be as profound a change as it seems. Human memories, inexact and labile to begin with, have long been the target of intervention, from cognitive-behavioral therapy to electroshock to medication. Treating conditions like depression at the engram level “is continuous with what we are already doing,” says Churchland, a leading philosopher of neuroscience.Meet the Two Scientists Who Implanted a False Memory Into a Mouse | Innovation | Smithsonian Magazine