The Volkswagen bus from my childhood was cute, full of charm, and wholly unreliable. We broke down in that top-heavy tin can constantly. Often we'd arrive at our destination without incident, but when we attempted to return home, we'd find the van maddeningly unresponsive. My folks deduced -- I'm still not exactly sure how -- that it was a fuel line problem. Since this was pre-internet and before the Car Talk guys, it's unclear how they determined that shaking the van vigorously from side to side would dislodge whatever was gumming up the fuel line or pump.

We shook that blasted van all over the county and beyond. Sometimes we were alone in our absurd misery; sometimes we had unfortunate relatives along for the ride. Once we even broke down on the way to school. I was mortified when we had to file out and assume the "shimmy" position. I recall the faces of the children on the bus as they peered out to gawk at our bizarre ritual. Or do I?

Memory is a tricky business.

French writer Marcel Proust -- who published his grand seven part novel "Remembrance of Things Past" between 1913-1927 -- wrote prodigiously on the theme of involuntary memory. One of the most enduring references in his masterpiece is the "madeleine" scene in which a taste of a tiny shell-shaped madeleine cake triggers a powerful flashback. Throughout the novel, the narrator's sensory experiences -- sights, sounds, smells -- provoke powerful memories and references to earlier episodes in his life.


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He uses these recollections to make sense of the present. But new science indicates that the present may also alter those memories that Proust believed indelible.

For a century the concept of memory consolidation held sway. The overarching narrative about memory, according to Stephen Hall, writing in "MIT Technology Review," was that "it was an unchanging neural trace of an earlier event, fixed in long-term storage." Upon retrieving a memory, the theory went, you essentially brought forth an enduring, immutable narrative of an earlier event. But, it turns out, memory is not unassailable.

Neuroscientist Daniela Schiller -- based at Mount Sinai School of Medicine in New York -- has been at the forefront of an extraordinary reassessment of the intricacies and operations of human memory. Schiller's work -- in conjunction with an ever-increasing body of evidence from like-minded researchers -- appears to indicate that we can actually modify the emotional impact of memory by combining new information to it or remembering it in an altered context. The implications of this are startling. If memories are in fact much less permanent and more malleable than we think, it suggests there may be methods to address post-traumatic stress disorder or other fear-based anxiety disorders -- and perhaps even addiction -- that do not rely on pharmacological agents.

Schiller arrived at New York University from Israel to study under Joe LeDoux. Her arrival coincided with important research by Karim Nader, a postdoc student in LeDoux's lab. Nader discovered that rats, who had previously undergone fear training through electroshocks, forgot their fear associations when they were injected with a drug that blocked protein synthesis in the amygdala -- the part of the brain believed to store fear memories. The timing of the injections was critical; the blocker had to be implanted during memory retrieval and reformation. Nader's experiment revealed that some aspects of our memories are actually "neurally rewritten" each time they are retrieved.

Schiller built on Nader's work and not only proved that this same memory reconsolidation occurs in humans, but also showed that memories could be altered without drug interventions. In her experiments, subjects viewed a blue square on a computer screen and then were given a mild shock. Once there was an association between the shock and the blue square, the fear memory was established. The following day, Schiller repeated the sequence that created the fear memory but showed the blue square without administering a shock. As long as it was in a narrow window of time, the fear association was broken. Hall explains the significance: "(I)ntervening during the brief window when the brain was rewriting its memory offered a chance to revise the initial memory itself while diminishing the emotion (fear) that came with it." The therapeutic implications of this are enormous, but no less significant are the cultural and personal repercussions.

Although Proust tapped into the powerful emotive aspect of retrieved memory, he -- like so many other writers and researchers across time and space -- misunderstood that these memories are actually rewritten each time we retrieve them. We incorporate into our memories new information that shapes the way we think. Explains Schiller, "My conclusion is that memory is what you are now. Not in pictures, not in recordings. Your memory is who you are now." In other words, our retrieved memories do not function as a file, describing dispassionately who we were then. Rather, oft-recalled memories explain why we are who we are today, resembling our current ideas more each time they are recalled.

My memories of our old VW van, then, are not absolutely accurate snapshots of being stranded on the side of the road, but instead, are a combination of emotions, ideas and reflections on those events and similar ones. As I recall those absurd episodes of the familial van vibrations, I fold into my own recollections my parents' and siblings' memories and the emotions I associate with each. In this way, our individual memories become collective memories, and instead of tying us to a particular moment in time, they connect us to history and community.

Rebecca Balint writes about history, education and culture. She welcomes your comments at bbalint37@gmail.com. Read her blog at www.reformer802.com/speakerscorner.