Science fiction movies like Total Recall (2012/1990) and Inception (2010) offer a glimpse of the incredible technologies the future may someday bring. In Total Recall, an ordinary factory worker discovers that his current life is a fabrication based on false memories implanted into his brain by the government. In Inception, a professional thief commits corporate espionage by hijacking his targets’ subconscious while they’re asleep. What do these movies have in common? They explore technologies that implant memories in someone else’s mind. But can this technology of science fiction, this romanticized brainchild of Hollywood, ever be possible?
A few years ago, Tonegawa and other researchers used a technique called optogenetics, to control neurons in mice that had been genetically sensitized to light. Using this technique, which involves shining a light to stimulate the neurons, they implanted a false memory in a mouse. In their experiment, mice were set up in a room where an electric foot shock took place, while a light was delivered via fiber-optic cable to their hippocampus (where memories are stored). The mice were conditioned to pair the shock with the room, facilitated by the optical stimulation to those neurons in that part of the brain. However, the mice exhibited the same fear, manifested by freezing behavior, when optically reactivated in an entirely different room where a foot shock was never delivered! It reactivated that memory of being shocked in that original room.
Rather than implanting false memories in the mouse brains, researchers like Theodore Berger looked in a different direction. Berger designed silicon chips to model the signal processing activity of the hippocampus, to essentially create an artificial implant. He found out how electrical signals from neurons move through the hippocampus to form long-term memories. Ultimately, this implant may help people who suffer from memory loss eventually to form long-term memories. Think Alzheimer’s! It may even help supplement our own memories, which can be unreliable at times, as shown in studies done by Elizabeth Loftus and others on eyewitness testimony and victims of abuse.
If the science fiction of implanting memories someday turns into science fact, we’ll have these movies to thank for in encouraging discussions about the moral and social implications. As American novelist Ray Bradbury once wrote, “Science fiction is the most important literature in the history of the world, because it's the history of ideas, the history of our civilization birthing itself. ...Science fiction is central to everything we've ever done, and people who make fun of science fiction writers don't know what they're talking about.” If we begin to imagine what a near future tomorrow might bring, we’ll have to start by using our own memory to recall the past and project ourselves into these possible futures.
Berger, T., Hampson, R., Song, D., Goonawardena, A., Marmarelis, V., & Deadwyler, S. (2011). A cortical neural prosthesis for restoring and enhancing memory. Journal of Neural Engineering, 8(4). doi:10.1088/1741-2560/8/4/046017
Ramirez, S., Liu, X., Lin, P., Suh, J., Pignatelli, M., Redondo, R., Ryan, T., & Tonegawa, S. (2013). Creating a False Memory in the Hippocampus. Science, 341(6144), 387-391. doi:10.1126/science.1239073
Sobel, C. P., & Li, P. (2013). The Cognitive Sciences: An Interdisciplinary Approach (pp. 77-79). Thousand Oaks, CA: SAGE Publications.