Unmaking Painful Memories


Date Published: July 15, 2020

Neuroscientist Daniela Schiller, PhD, grew up in the shadow of the Holocaust. Her father was a survivor, but he refused to talk about his experiences. Propelled by his silence, Dr. Schiller became an expert on how the brain stores fear memories. In 2010, she published a landmark paper in Nature that shed light on a neurological process called “reconsolidation,” in which memories become subject to change when they are recalled. In recent years, she has explored the power of imagination and mindfulness to alter the intense emotions associated with painful memories. Her research may point the way to new treatments for a range of anxiety disorders, including post-traumatic stress disorder (PTSD). 

In this interview she talks about how learning to see memories as malleable is liberating and describes how her research changed her understanding of her father.

Podcast Transcript 

Host: 00:00
You're listening to Road to Resilience, a podcast about overcoming adversity. I'm Jon Earle.

Dr. Daniela Schiller: 00:08
At first your memories are who you are. They define you. But as my research progressed, and I thought about it more and more deeply, I realized that you actually interact with your memories, or at least I started interacting with it. I started observing memories that perhaps weren't as accurate. I started observing memories that had reason why they popped out and observing more agency in addressing memories. And it had a liberating aspect in the sense that negative memories actually may have never happened, or they didn't happen as I conceived them.

Host: 00:50
My guest today is Dr. Daniela Schiller. She's a neuroscientist here at Mount Sinai, and her research focuses on fear memories. In other words, what happens in our brain when we learn and in some cases unlearn to fear something. Now, as some of you may remember, back in October for our Halloween episode, I interviewed Dr. Anthony Lacagnina, also a neuroscientist who studies fear memories. And I can't help it. I think this subject is so interesting because the more that I learn about the malleability of memories, how they can change as we recall them, the more I feel a sense of hope, a sense of freedom from our memories. So we're going to talk a little bit about the science, but we're not going to go too, too far into the weeds.

Now, that being said, there are a couple of concepts that I think are really important to understand going into this. The first is called "consolidation." So that's what happens when you form a memory, your brain etches that memory into itself. Think of it like ink drying on a page. Okay. So that's consolidation, you're consolidating the experience into a memory. The second is reconsolidation. That's what happens when you recall that memory and you bring it up. And it turns out that in that recollection, the memory becomes unstable. It can actually change. And that's the moment that Dr. Schiller and others are so interested in because it's in that change, that flexible period, that we might be able to tamper with it in a positive way. It's not that we're talking about erasing memories, but we are talking about the potential for science and the potential for clinicians to reduce the intensity of emotions associated with memories, those emotions that can be so overpowering sometimes and that can make it difficult in some cases to lead full fulfilling lives. But this interview goes in so many interesting directions to me. It's not just about that specific concept. We talk about the power of imagination. We talk about mindfulness. We talk about collective memory and the way that it works and the way that it sometimes doesn't work. So I love this episode. I think there's so much interesting food for thought here, and I think you're going to agree. So here is Dr. Daniela Schiller. Enjoy.

Dr. Schiller, welcome to Road to Resilience.

Dr. Daniela Schiller: 03:03
Thank you for inviting me.

Host: 03:05
You grew up in Israel, and your father was a Holocaust survivor. What role did that play in your decision to study fear and memory, do you think?

Dr. Daniela Schiller: 03:14
So explicitly it actually played zero role because I was never aware that it had any role. There was a strict separation between my family and my science. So only in the last few years when I started thinking about it and engaging in storytelling and science communication is when I made the link, and then everything fell into place. So it was more of a retroactive realization that it may have played a very big role, only I was never aware of it. And now I think it might have.

Host: 03:56
How would you describe the role as you've come to understand it?

Dr. Daniela Schiller: 04:00
Oh, well, when you grow up in Israel, you learn about the Holocaust from very early on. Even before you understand what is the siren that everybody has to pose and stand in silence for a minute to reminisce about the Holocaust. You do that even before you understand what it is and whatever happened. There was this darkness that you grow up with. And for me it was very personal because I always knew my father had something to do with it, but he never talked about it. Never identified himself as a Holocaust survivor, ever. You know, there was not ever discussion on that. We never knew what actually happened. So there was this dissociation between the personal experience, which I basically knew nothing about and the social-national experience, which means kind of the Jewish people's tragedy. And growing up with that is really horrible. And also I think it affects you in many ways. I guess I'm considered second generation. You inherit a lot. It even ripples all the way to the third generation. And whether you want it or not, this is the reality you live with--that that type of tragedy and darkness is part of life.

Host: 05:19
I want to return to this with a question later that now that we've touched on this idea of collective memory and the passing on of trauma, I definitely am going to ask you in a moment. But I want to switch gears to the two models of memory. So there was once a model that memory was fixed. It was like a book. Something happens to you, it's inscribed in the book. And when you remember it, you essentially pull the book off the shelf, look at it, close it and put it back. But the text itself doesn't change. And over the past several decades, that understanding has been challenged. And you've been part of that. Can you just for a layman audience lay out where we were with memory and what our current understanding is?

Dr. Daniela Schiller: 06:03
Yeah, so the classic view of memory that dominated the entire 20th century was that events are formed through a onetime process called "consolidation." So when you experience something, it has to be actively stored in the brain. And this involves structural changes--long-term changes in the brain that you can observe at the neurobiological level. And once this happens, you have formed a memory that you can retrieve again and again. So we know that that process is happening, but we assumed it happens only once, only when the original memory is formed. But then there was evidence during the 1960s, a little evidence, that was revisited in 2000, around 2000, with a few studies and that created a burst of studies since then in the last two decades that show that it's not a one-time event. Consolidation, or something like consolidation, can happen when you retrieve a memory. When you remember something it can go back to an unstable state in the brain, and if it's not restored just as it was stored in the beginning, then it might be lost or modified.

Host: 07:20
I want to check my understanding. So it means that when you recall a memory, so you're taking that book off the shelf, in the period that you're reading it and putting it back on the shelf, that memory is subject to change, is what you're saying. Correct?

Dr. Daniela Schiller: 07:35
Yeah. It's actually a metaphor I used once that--I thought about it as if, yeah, just like you say, you take a memory, so imagine each time you take a memory, sorry, a book from the shelf and you read it, it changes slightly.

Host: 07:49
You write some notes in the margin, you cross something out, that sort of thing.

Dr. Daniela Schiller: 07:53
I like to think about it more in a Harry Potter type of way. You know the words and the pages kind of switch location and change structure just because you read it. And once you put it back, it's just not the same.

Host: 08:09
So where does the 2010 study that you were a part of fit into this? How did that push our understanding of memory forward?

Dr. Daniela Schiller: 08:17
Maybe I can just give an example, like an everyday example, because the technical details of the experiments are kind of, they're a little bit difficult to grasp. So yeah, imagine that you walk in the street and suddenly there's this vicious dog barking at you. Let's say that dog has this red collar. So you developed, you could develop a fear-conditioned response to the red collar. So whenever you see that you remember the dog and have a startled response or that would be very disturbing you. But then what you could do is see the red collar again, remember the dog, but then have a whole different experience. For example, that red collar will be associated with a prize, or you will just see it all over the place all the time that you will say, "Okay, it's just not the same again." And then, in this way, with these types of various behavioral interferences, you could intervene with the reconsolidation process of that threat memory such that the next time you see the red collar, it wouldn't have the same meaning.

Host: 09:30
Like it wouldn't be scary, or it wouldn't have the--

Dr. Daniela Schiller: 09:33

Host: 09:33
But you'd still remember that there had been a dog and a red collar and all of that, but it wouldn't have the power that it had over you, right?

Dr. Daniela Schiller:  09:40

Host:  09:43
It's similar--so I'm familiar with this idea of exposure therapy that psychiatrists use, for example, with people who have phobias. If you have a fear of flying, they might expose you in a very kind of sophisticated, measured way to flying to help you to get over it. Did this research change the way that we think about exposure therapy?

Dr. Daniela Schiller: 10:01
Yes, you're touching upon a very important and subtle point. So we are familiar with exposure therapy and various techniques to learn to suppress the memory and develop corrective behaviors. And we always regarded that as new learnings, developing new sets of behaviors to change the way we think and operate. What the reconsolidation line of studies suggests is that there's a subtle difference. Instead of creating new learnings, what you actually do is reactivate the memory, almost like injecting or stimulating the memory with these new behaviors, such that they are getting incorporated into the original memory and change the original memory permanently, to say it in very strong words.

Host: 10:55
So the science can inform how those interventions are designed, right? Because now you know more about the specific timing that an intervention has to take place among other things, perhaps, for it to be effective. Which means that you're opening the door to improved interventions for people with, say, PTSD or extreme anxiety or phobias and things like that.

Dr. Daniela Schiller:11:15
That would be the great hope of that line of research, that you could in a way use something like--instead of electrical stimulation of the brain or pharmacological administration, you will have behavioral stimulation. It will basically sort of reverse engineer the behavior from the understanding of the neural circuits and tailor a very particular behavior to change the activity of these neural circuits that represent the memories and give rise to behavior. Ideally that would be a very good outcome of that line of research.

Host:  11:54
I think this is a good point to say why I love your research. Because for me it's so hopeful. It carries such potential, knowing that our memories are not fixed and they don't necessarily have to have power over us. And it doesn't mean that we have all the answers yet, that we know how to tamper with them--that's kind of a pejorative word, but to alter their emotional resonance, but we're moving in the right direction. And that's super cool to me. For stuff like addiction and others that are so pressing, it can't come fast enough. There are two studies that you published in the last few years that are along these lines, and I'm curious to hear how you think about their potential. The first had to do with imagination and the power of imagination versus an actual exposure. Can you tell us what that study was all about and what made it so interesting?

Dr. Daniela Schiller: 12:49
We were inspired by various types of psychotherapies that use imagination in the clinic. People use imagination to change their ways, to think differently about their behaviors and their memories. We wanted to put it to the test. And our hypothesis was that perhaps through imagination, you can activate the brain processes and regions that would respond to a real-life situation. And we did. What we found is that, just as you would have a real exposure, you could also imagine the exposure and it would be as effective.

Host: 13:26
This is mind blowing to me, the idea that imagining was as powerful as exposure.

Dr. Daniela Schiller: 13:32
I think it's amazing. I mean, it's the whole inspiration for the research, which I feel in everyday life that we have a lot of brain power. We can do a lot by enhancing our agency in terms of our thoughts and emotion. We have, I think, greater control than we believe we do. Emotions is something that is happening to us. And usually memories are something that just comes up or is attacking us. But if we pay attention and use it more deliberately, I think we can discover that we have a lot of power over it. And in this way it will give us more freedom, more space to work, and we will be less passive and deterministic in our approach to our own personal life.

Host: 14:25
This is something that comes up a lot in my conversations about resilience—the idea of imagination and choice. That even in the most dire circumstances, there's still a window, it's very tiny and it can be very hard to access, of choice, of saying, "I'm going to choose how I think about this." And that choice can have huge implications for the way that the person deals with—it could be trauma, it could be their memories, it could be the physical aspect of an injury or an event. So there seems to be a real connection between that imagination that you're talking about and that you were observing in the lab and the conversations about resilience.

Dr. Daniela Schiller: 15:07
It's like a sliver of hope in the darkest times. If you maintain that belief or are able to find it, it gives some hope.

Host: 15:18
And I think this is probably a good time to ask you how your work has impacted the way that you live your life.

Dr. Daniela Schiller: 15:25
I think it has affected me profoundly because I started thinking about memories in a whole different way. And I think that the interaction aspect of it was the most dramatic change, because at first your memories are who you are. The memories are yourself, they define you. But as my research progressed, and I thought about it more and more deeply, I realized that you actually interact with your memories, or at least I started interacting with it. I started observing memories that perhaps weren't as accurate. I started observing memories that had a reason for why they popped out and observing more agency in addressing memories. And it had a liberating aspect in the sense that, like you said earlier, negative memories actually may have never happened or didn't happen as I conceived them. So you become more focused on the present, and memories become information about your current state. Because whatever you retrieve tells you what is currently happening. And your approach to memories is also very informative of how you feel now. So it almost changes your perspective. Instead of mental time traveling to the past, you actually remain in the future and just observe what has just occurred now. I think it's a pretty profound experience that you have with something that you just accepted as just something you have to live with. And it's a constant process that I think is interesting and I'm still interrogating.

Host: 17:13
To me it's the difference between your memories being like a ball and chain that you just drag around, versus a companion, not always a welcome companion, but a companion that you have a relationship with, that you're in dialogue with, and that you can change your relationship to.

Dr. Daniela Schiller: 17:31
I think it resonates with processes that are occurring yet in mindfulness. So I'm not a meditator, I tried a little bit, I'm not an experienced meditator so I'm not going to talk from experience, but mostly from a little experience and what I read and heard. But it sounds like something similar that you would target in mindfulness and meditation practices, which is to observe, to observe your thoughts, to accept them, to let them happen and be present with them. It's just interesting that it occurred through research, through really looking at the neurobiology, which I find very inspiring and surprising. And I do hope that there will be more and more of a merging between neurobiology scientists and research and practitioners of meditation, and also therapists, clinicians that work on mental health. I think we all work toward the same process and eventually reach even the same conclusions only through different techniques and different perspectives. But it's nice to see how we all converge on this similar process of flexibility of emotions and memories and the way we interact with them.

Host: 18:48
That's so interesting though that you said you don't have a mindfulness practice.

Dr. Daniela Schiller: 18:53
Well I'm not a meditator. You know some people meditate for 40 years. I meditated a little bit. But I did do a study on it that had people practice meditation. It was a collaboration with colleagues that had a group of people that undergo meditation for eight weeks of mindfulness training. And it changed their fear responses or their ability to diminish their fear responses. So we see a relationship in what mindfulness practice, what it gives you in terms of flexibility of emotion and thought.

Host: 19:31
So in other words simply being familiar and somewhat practiced in the techniques of mindfulness seem to allow a person to have more control over essentially the emotion connected with memories.

Dr. Daniela Schiller: 19:43
Yes, exactly.

Host: 19:45
I really feel like I should start a meditation practice. That's all I was thinking as I was reading about your work.

Dr. Daniela Schiller:  19:54
Me, too! I wish I could do it full time, you know, like these people that go to month-long retreats of meditation, but I just have too much work in the lab.

Host: 20:04
The question I wanted to ask you from the very top was about collective memory. And I know this may be just so completely outside your wheelhouse and outside of the research realm, but talking about Israel, talking about the Holocaust, talking about even the conversations that are taking place right now in this country about collective memory and trauma. Have you been thinking about that at all?

Dr. Daniela Schiller: 20:33
Yes, especially my conversations with my father that happened actually very late in life, almost in the nick of time before he passed away, and growing up in the shadow of Holocaust memory gave me some interesting realizations about the purpose of collective memories, and the function it serves to the society versus the individual. Because what I realized is that sometimes there is a mismatch between the personal memories, individual memories of people that underwent the Holocaust, and what is remembered collectively. So for example, what I learned from my father is that there were very little moments, intimate moments that were the most emotional and focal to his experience, but he could never share them because he thought they were ridiculous. Because they didn't match what is socially or collectively remembered, like the horrors and gas and firing squads and violence. And he almost, he said, "Yeah, of course, I did that. And he shot me. And this one did that to me." So he went through all these horrible processes, and he's like, "Yeah, sure." But it's not that. It's this event, like this person who gave him a sandwich. And so then I realized that sometimes we needed to remember it in such a horrible way almost to cope with it as a society. Because it helps us to, I think, distance it from ourselves, because this is this horrible thing that happened, it's not going to happen now. It's actually even in some way detached from our present experience. So it serves that function, but then it fires back on the individuals. It puts a huge burden on them. They have this joke that if you went to Auschwitz, you're like a celebrity. Or, you know, you can more easily talk about it because it will be more well-received or something like that. These are the real subtleties I was completely unaware of and I don't think are part of a general conversation in our society. But I think it's important to see how the collective memory affects those individuals for which we remember.

Host: 22:59
I'd never considered that.

Dr. Daniela Schiller: 23:01
Yeah. And I think we have these aspects, we see them in various other types of situations, various traumatic memories that what you're left with is sometimes guilt or a sense of responsibility, shame. And most of research is focusing on fear, on the fear response, survival-defensive response. And I think it misses these subtleties that I hope we could incorporate more and more into the understanding of the neural mechanisms and behavioral mechanisms that underlying our response to trauma.

Host: 23:37
Was your father ever able to get treatment?

Dr. Daniela Schiller: 23:40
No, he wasn't that type of person. He was the type of person who was very suppressive and he really just shared a little bit with me very late in life. But another thing I learned from him is that suppression is actually good. That's another thing, you know, suppression that has a bad reputation as if, "No, we don't need to suppress." And the whole purpose of therapy is to bring everything out. But I also realized that, speaking of reconsolidation, the purpose of it is to incorporate the old information into your present life. But some information is just not incorporate-able. It's just too extreme. And in some situations maybe really the best way is to suppress. The question is, what is the price of suppression? I think this is how you balance what is better. If there's a high cost to suppression such that it makes you numb or somewhat dysfunctional, or it really takes a lot of energy, maybe you want to deal with it. But if not, and you manage to live with it, maybe it will be just too complicated to have it in your present life. There's a balance to it. So it actually gave room to a process that is adaptive in a way. Suppression is adaptive. So I've made room for that in thinking about reconsolidation and the constant changing of memories and thought that some memories—maybe it's fine. Maybe it's fine that they're in there and not reactivated. And also counterintuitively the most precious memories that are really the happiest unique moments are also ones that you don't want to touch. Maybe they also need to be buried otherwise they will be trivialized by mundane and new daily experiences, and then they wouldn't be precious again. So that's another form of memory you would like to protect.

Host: 25:43
There are so many, so many more mysteries it sounds like to understanding memory. Is there one that for you is like the Holy Grail? That if you could just snap your fingers and understand something fundamental, what would it be?

Dr. Daniela Schiller: 26:01
There are many questions. I think one of the biggest mysteries is, why do we remember? Why does a memory come up? We actually don't know. A lot of memories could be triggered during the course of this conversation, but others not. Why? Why these memories and not others? Why would some memory suddenly pop out, almost like this cartoon of, like rats pop out from different holes. Memory is sort of like that. You have no idea why. And I think there's a lot of information there, and I would like to see what brings a memory out.

Host: 26:44
Great, well I think that's a great place to end. Dr. Schiller, thank you so much for being on the podcast. I really enjoyed speaking with you.

Dr. Daniela Schiller: 26:52
Thank you.

Host: 26:54
Dr. Daniela Schiller is a Professor of Neuroscience and Psychiatry at the Icahn School of Medicine at Mount Sinai. If you want to learn more about her work, go to the show notes. We'll include a link to her website, where you'll find articles, popular and scientific, that go into more depth. And if you enjoyed this episode, please leave us a rating and a review on Apple Podcasts. It helps other people find the show, and that means so much to us and the people that we speak with. So thank you so much for doing that. Road to Resilience is a production of the Mount Sinai Health System in New York City. It's produced by Katie Ullman, Nicci Hudson, and me Jon Earle. Lucia Lee is our executive producer. We'll be back soon with more episodes, and until then stay safe out there and be well.