Humans are fallible. We’ve all goofed up over the years in ways large and small. Who could forget, for instance, accidentally calling your teacher “Mom?” Or maybe you accidentally let slip that you know a little too much about the Gilmore Girls while pumping iron at the gym. Either way, most of us tend to know when we’ve embarrassed ourselves, and those memories tend to linger in our minds like an unwelcome guest at a party. “Hey,” they say randomly, while you’re getting dressed in the morning, “Remember that time in 1998 when you thought that woman was pregnant?” Who wouldn’t want the opportunity to make like a Goodfella and fuggedaboudit?
Insubstantial (and frequently annoying) as they are, memories also have the potential to cause real harm, too. Look at anxiety and post-traumatic stress disorder – conditions that may arise after someone has a particularly alarming or frightening experience. During traumatic events, multiple memories can form simultaneously, including incidental information like certain colours or objects. In a traumatic experience, seeing these objects again, even in an innocuous context, can trigger an anxiety attack. Is there any way that one could pull an Eternal Sunshine and simply “snip out” the offending memories? For a way to do that, look no further than those humble creatures eating your lettuce.
We often talk about “mind reading,” as though the human mind is an open book anyone can flip open and rummage through. It’s a nice phrase, but the reality is somewhat more complicated. The mind isn’t so much an open book as much as it is a book that’s been put through a paper shredder, shaken in a tumbler, and then haphazardly glued back together into a seemingly random configuration. Our neurons – those special cells that make up our brain – store memories together in a dense, jumbled mishmash. That’s why it hasn’t been possible to just eliminate the neurons holding our memories, even if we could track them down. You might forget that time your pants fell down in the fourth grade, but you might also forget how to parallel park.
Brains file away long term memories, in part, by increasing the strength of connections between neurons and maintaining those connections over time. Scientists have long held that the neuron structure of the brain is a gigantic game of cellular Jenga, where removing any one memory might cause the entire assemblage to come crashing down.
A new study from the University of Oxford put that theory to the test by stimulating two sensory neurons connected to a single “motor neuron” of a snail. One sensory neuron was stimulated to induce an “associative memory” that provides the snail with important information regarding its surroundings, and the other a “non-associative memory” of a random event in its snail-y life. Researchers measured the strength of each connection and found that the increase was produced by a different form of protein for each memory. Essentially, memories could be “erased” – more like suppressed—by blocking one of the protein molecules responsible for calling up that memory.
We’re not quite at the stage when you can just walk into a clinic and ask to forget all the memories of your ex just yet, however. Any future drugs that control the development and implementation of protein memories will likely take decades of testing and strict regulation, not to mention the ethical minefield associated with turning our brains into a cutting room. Do our experiences make us who we are? And if so, should we be allowed to simply “cut” the experiences we don’t like anymore? As we probe further and further into the mysteries of the brain, these are all important questions that we shouldn’t forget.