The science behind the film Eternal Sunshine of the Spotless Mind
In the new film Eternal Sunshine of the Spotless Mind, starring Jim Carrey, two lovers who recently broke up impulsively decide to take a pill that will erase their memories of each other. An interesting premise, though it would be tough to find a scientist who believes it will ever be possible to pinpoint and erase a specific string of memories. It does, however, seem possible to tinker a bit with long-term memories, particularly if they’re associated with strong emotion.
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In a 2000 study for instance, New York University researchers trained lab rats to associate a tone with receiving an electric shock. Soon, the rats froze in fear when they simply heard the tone. Then the researchers gave some of the rats a drug that prevented the amygdala–a structure in the brain believed related to the processing of emotions–from making proteins necessary for memory storage. After waiting a few days, researchers played the tone again. Normal rats were still fearful. This time, though, those that had received the drug were not, apparently having forgotten the earlier association.
Then there’s a University of California–Irvine study, in which researchers showed participants a series of slides, telling them either a mundane or gripping story about each image. As expected, the participants had more vivid memories of slides associated with the gripping story. The experiment was then repeated, except that half the participants were given the beta-blocker propranolol one hour before the slide show. Two weeks later, the researchers found that participants who heard the emotionally rousing story and also received the beta-blocker recalled the slides no more accurately than participants who heard the mundane story. Propranolol has also shown some promise in lessening the symptoms of post-traumatic stress disorder.
If a pill could eliminate bad memories, should you actually use it? Some situations, like childhood abuse, seem to offer a compelling, "yes." But it could also be argued that the dulling of bad memories might make one too comfortable with suffering and injustice in the world. As Holocaust survivors say, "Never forget."
