Fear can take many forms, from minor phobias to life-altering conditions such as PTSD. Now, new research is shedding light on how these so-called fear memories could be changed. Neuroscientist Daniela Schiller will discuss her work on the neural mechanisms of emotional control and potential ways to modify or “erase” fear memories. Schiller recently answered a few questions about how memories are created and lost.
How did you first become interested in studying emotional memories?
It wasn’t an explicit decision. I started with philosophy and psychology, and I was interested in the brain and the mind. And the combination is the neural basis of behavior, and within behavior, emotion is fascinating because it’s the least willful process we have. We think emotions just happen to us, but they don’t just pop out of the blue. It’s interesting to look at the mechanism and see that it’s a very distinct process in the brain that you can observe and counteract and modulate.
How have you explored ways we might control or erase fear memories?
First, we create a fear memory in the laboratory. It’s a simple memory, a cue associated with a mild electric shock. Then, we remind the subject of this fear memory, and when it’s active in the subject’s brain, we try to manipulate it. You can do this by giving a drug or by doing some behavioral interference to provide new information that gets incorporated with the original memory and modifies it. Once you re-activate the memory, it goes into an unstable state, and this is the moment when you can interfere with it.
How do memories enter an unstable state, and how might we use this information to “forget” fear?
If you don’t consolidate a memory—meaning there’s no strengthening of the trace in your brain—it’s going to go away, and you’ll forget the event. If you do consolidate it, then you create a long-term memory. But whenever you retrieve a memory that was already consolidated, it becomes unstable and needs to be consolidated again—hence, “re-consolidation.” You re-store the memory. Consolidation and re-consolidation are the windows where memory is vulnerable. And if you prevent a memory from being consolidated or re-consolidated, you can “erase memory.” In other words, every time you revisit it, you have a new chance to forget.