• Image about Elizabeth Phelps
Photograph by Chris Korbey

Forget everything you think you know about memories. Scientists have discovered a way to change — and even erase — them.

Let’s start with an easy one: You know who Jim Carrey is, right? And you probably remember his role as the lovelorn Joel Barish in Eternal Sunshine of the Spotless Mind. And maybe you remember how strange that movie was — how it dealt with the implications of erasing one’s memory — but how tender, too, because love connects even those who don’t want to think about each other.

Now, what if that movie were true? What if you really could erase painful memories, so that maybe you remember the melancholic Jim Carrey from Eternal Sunshine but not the Jim Carrey who pretends to talk out of his derriere in Ace Ventura: Pet Detective? Would you want to live in such a world?

Whatever your answer, here’s the spoiler: You’re already living in it.

Elizabeth Phelps is on the phone from New York, talking about how memories are retrieved. A psychology professor at New York University, Phelps explains that there’s a theory in the academic world called consolidation, the process through which memories are stored. An event happens, and your mind takes in a portion of what it experiences: a sampling of what you see, hear, smell, and feel, as well as your emotional response to the event.

By way of example, and because stressful events tend to get stored as memories, let’s say that while you’re out on your morning run, a dog attacks and bites you. Afterward, you remember the dog and what he looked like. But you also remember how loud and unfriendly his bark was at close quarters. You remember the bursts of hot breath on your leg, the pain of the dog actually closing his teeth on your flesh, and finally — and this is often more memorable than the pain itself — the fear that such a bite elicited; that ingrained fight-or-flight response.

Now that’s a scary event, and one that will be stored as a fearful memory. The theory of consolidation argues that when the memory is retrieved, some of what you took note of comes with it: the size of the dog, the loud bark, the hot breath, the bared fangs, the pain and the fear. When academics think about consolidation, they argue that the totality of this memory — all it comprises — cannot be altered. You remember the same bark, the same pain, the same fear, every time.

But in the last 10 years, a new theory has emerged. “There’s this idea that actually every time you retrieve a memory, it has to go through this restoring process,” Phelps explains. “And that’s called reconsolidation.”

In reconsolidation, the memory is recalled — the bark, pain, fear — but it can be altered before it returns to storage. In particular, a memory’s physiological component — the fear, in this case — can be shaped and lessened. “Memory,” Phelps says, “is adaptive and flexible.”

This insight has triggered Phelps’ research and reams more from scholars across the world. The implications of the burgeoning literature are just beginning to be felt, and though the findings could have some everyday applications, the big hope is for victims of trauma: women who have been sexually assaulted, say, or soldiers returning from war. The idea is that, someday, their mental scars might heal as fast as their physical ones.

There are a few different ways to shape memory. If someone has a fearful memory, for instance, that person can be taught to accept a new one — a second memory — that isn’t moored in fear. This occurs through conditioning the individual not to be scared of whatever is causing the fear. So if someone is afraid of snakes, the process would involve showing that person a picture of a snake and ensuring that nothing bad happens to the person. And then introducing a fake snake. And then a real snake, until the person has a new memory of snakes to counteract the old, fearful memory of them.