How much can you trust your memory? Not a whole lot, according to Daniela Schiller, a Mount Sinai School of Medicine neuroscientist. To a packed audience at MIT Technology Review’s 2013 EmTech conference on Wednesday, Schiller explained how research in her lab and others is uncovering how memories are tweaked each time they are recalled.

“This decade is the time of a revolution in the way we perceive memory,” Schiller told attendees. For the previous century, the accepted view was that once captured and stored in neural circuits in the brain, a memory could be retrieved but could not be rewritten. In that view, every time an experience is relived, it is the same, over and over.

Now, however, researchers understand that that the process of recalling a memory actually changes it. “Each time you retrieve a memory it undergoes this storage process,” Schiller told me over the phone the day before EmTech. That means the memory is in an unstable state, rewritten and remodeled every time it is retrieved.

“We don’t really remember the original; we remember the revised version,” she said.

So how much can we trust our memory? Probably less than most of us do. “Every day we create false memories,” said Schiller. Which means we put way too much faith in memory in the legal system. “You can influence eyewitness testimony just by investigating an event,” she said. And when you disagree with your spouse about the details of an event that happened 10 years ago, you both could be wrong.

But there is a positive side to our moldable memories. The memory of traumatic events plague many lives and can even lead to psychiatric illness. The new understanding of memories means they can be “updated.” Schiller says that if you block the memory storage process, you might be able to eliminate the memory. Or, if you recall a painful memory in a context of positive emotion, the tenor of that negative experience could change. “We aren’t a slave to our past,” said Schiller. “If you are stuck with a bad memory, it is just one version; it’s not exactly the truth and you can revise it,” she said (see “Repairing Bad Memories”).

So how can we know the reality of a memory? Look to art, said Schiller. “Art has a very intimate relationship with memory,” she said. “The only way to keep memories as they are … is to carve them into a story or art form that captures the original emotion.”