Exploring How Emotion, Aging, and Sleep Impact Memory

Image above: Portraits of Randi Martin (L) and Elizabeth Kensinger (R).

In my presidential column from the October Observer, I discussed how research in cognitive psychology and cognitive neuroscience has moved from being focused solely on the “colder” aspects of cognition to including “hotter” aspects, investigating the role of social–emotional and cultural factors. My goal was to emphasize to the broad membership of APS the existence of these new directions and the possibilities these changes open up for collaboration.  

Here I take a deeper dive into one such direction in a conversation with APS Fellow Elizabeth Kensinger, one of the keynote speakers for the 2025 APS Annual Convention. Her research has been ground-breaking on the role of emotion in memory. In our conversation, we talked about the state of the field when she started graduate school, the factors leading to her initial pursuit of these topics, her major findings, and future lines of research. 

Martin and Kensinger spoke on November 5, 2024. Edited excerpts of their conversation follow. 

MARTIN: In my October presidential column, I commented that until recently, much of the work in cognitive psychology had not dealt with social–emotional factors or cultural influences. To check this impression, I looked at the subject index in Eysenck and Keane’s cognitive psychology text from 2005 (Eysenck & Keane, 2005) and found there was only one entry on one page about emotion, with “flashbulb memory” as the context. In the 2020 online version of this text, this picture had changed a lot, with over 40 entries having to do with emotion, some dealing with emotion in autobiographical memory. Is this your feeling as well, about a big change having happened in the last 15 to 20 years? 

KENSINGER: Absolutely. When I started to do this work, some important foundational studies had already been done, but there was a lot that we didn’t understand about how emotion and cognition interacted and how emotion and memory specifically interacted. What I had been taught at the time was that these mostly were in opposition. That is, having an emotional response just shut off any type of cognitive processing. We now know that can sometimes be the case, but there are also many, many other ways in which emotion and cognition work together and support one another and have reciprocal connections. So, it’s been really an exciting time in the field to watch those developments happen. For so many of the developments, they are really building on foundational cognitive psychological work that had to happen first. That is, once we understood enough about attention and perception and memory, then we could start to bring in these questions of what happens when we’re stressed, what happens when the experience is emotional, and start to answer those additional questions. 

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MARTIN: With regard to the factors influencing the beginning of your research on emotion, I saw that you had worked with Suzanne Corkin as your principal advisor in graduate school. Of course, she is extremely well known for her work on the amnesic individual H. M. and the dissociations in memory systems that he demonstrated. I saw that your early research was not on amnesia, though, but instead on memory processes in Alzheimer’s disease. What were the influences that got you started on the topic of emotion and memory? 

KENSINGER: It really did come from the neuropsychological perspective that I was immersed in, in Sue Corkin’s lab. In particular, I was doing a study looking at the relation between working memory and long-term memory ability in patients with Alzheimer’s disease. As part of this, a caregiver often came in and spent the day with them. I often had lunch with the individual with Alzheimer’s disease, but also with whomever had come in to consent and often to observe parts of the test session. So, it was this really wonderful opportunity to have a genuine interpersonal connection with these families. Anecdotally, what they would often tell me—not as an insult to my grad work (but maybe a little bit)—was, “It’s not really bothering us [the families] that they can’t recite these digits or remember these word lists that you’re presenting to them. What’s affecting our lives is that they don’t remember that they went to the first birthday party of their granddaughter a couple of weeks ago. They don’t remember that someone passed away, and we can’t figure out whether to keep reminding them or not.” These were their experiences. I kept hearing that it was their forgetting of these emotional memories that was really difficult for the families. 

Built into some of those questions was what I thought was a really interesting assumption, which is that these memories should be easy to remember. These families wondered, why is it so hard for this individual to remember what should be these highly salient memories? In an attempt to try to be helpful, I tried reading the literature so that the next time someone asked, I would be able to tell them why this happened and maybe refer them to a study. But there was nothing at that time! There had not yet been a study looking at emotional memory in individuals with Alzheimer’s disease. That just seemed like such an important gap. So that was actually the first study I ever did of emotional memory, looking primarily at Alzheimer’s disease, and I had older adults as the control to those with Alzheimer’s disease (Kensinger et al., 2002). That was one of those peeling-the-onion moments where I thought, “Oh, my goodness! We don’t know what’s happening in healthy older adults. We don’t really know a lot of what’s happening in younger adults. Let me backtrack and start a little earlier in trying to understand this.” This desire to backtrack motivated my dissertation research, examining emotional memory in younger adults. 

MARTIN: That’s very interesting. I wondered how the connection of neuropsychology and working with Corkin led you into this line of research. When you think about the importance of emotion to memory, you would think evolution would have something to do with this. That is, why do we have these emotions that tell you whether something’s good or bad? You would hope you’d remember those things that either led to good or bad outcomes and that you would remember what the outcome was.  

KENSINGER: Certainly, now that there’s so much more research connecting memory to our ability to understand the present moment and to make future projections, it leads to thinking about the adaptive function of memory. It’s the emotional moment that you want to be using for those other functions of memory. So, there are a lot of reasons to think that there would be prioritizations of these emotional experiences. 

MARTIN: That makes sense that you would use emotional memories from the past in planning the future. Going back to your background and early influences, I see that after grad school you went on to do a postdoc with Dan Schacter at Massachusetts General Hospital (MGH) and Harvard.  

KENSINGER: I became a postdoc when fMRI methodology still was pretty young. It was a wonderful opportunity to be in the Department of Radiology at MGH, getting training in the way that fMRI methods worked. Working with Dan Schacter in the psychology department at Harvard, of course, is like a dream come true for anyone interested in memory. That was such a fun time! He had done some work on emotion and emotional memory in the past with Kevin Ochsner and some other individuals who had been in his lab, but it was still a relatively new focus for him. For me, it was just such a rewarding environment to be in, to be surrounded by brilliant scientists in his lab who were all interested in memory, but not all interested in emotion. We had all of these great opportunities to have conversations across different elements of memory. One of the most fun studies that I did during that time was in 2004, when the Red Sox and the Yankees were playing against one another in the playoffs. There was the surprise victory of the Red Sox, that even me as a diehard Red Sox fan didn’t fully expect! Here was a moment when we could actually design a semi-controlled behavioral study to look at the effects of positive or negative emotion on memory, because the valence of the emotion varied based on whether you were a Red Sox or Yankees fan. Dan was such a great collaborator for work like that. As a baseball fan himself, he was all in. Us being the unusual people that we were, right after this win, late at night, we’re emailing back and forth about the memory experience questionnaire that we were going to design and send out. 

MARTIN: Not drinking the champagne. 

KENSINGER: Yes, exactly. Exactly. 

MARTIN: Resulting in the paper with Schacter on positive and negative emotions’ effect on consistency and confidence for memory of a real-life situation (Kensinger & Schacter, 2006). Now, in my initial column, I talked about a memory I had for when, as a graduate student, I gave an introduction for a famous psychologist at a department colloquium. I remember my nerves in speaking in front of the whole department and my feeling of relief when the audience laughed at a joke I made but remember little about the talk except for some general gist. Does that fit with your general findings on emotion and memory? 

KENSINGER: Absolutely. That fits very well with the idea that emotion selectively enhances memory. There are some parts of an emotional experience that we tend to remember pretty well and accurately, but then there are lots of other parts of it that we don’t remember any better than a neutral event. And, in fact, there are times when emotion can lead to more forgetting of some of those more peripheral elements that aren’t high priority at the time that you’re processing them. My laboratory has done a lot in trying to understand the role of attention and encoding versus consolidation over sleep-filled delays, versus what’s happening at retrieval, and how all of these together combine to influence memory. It’s also been really terrific to see how other groups like Mara Mather’s group or Deepu Murty’s group have added so much deeper understanding to what some of the physiological mechanisms are that are leading to these types of selective effects of emotion and reward as well as in memory. 

MARTIN: Glad to know that I’m not too unusual. At what point did your research really turn towards the aging issue, focusing on healthy aging and not necessarily on Alzheimer’s or other disorders? 

KENSINGER: There was this discrepancy in the findings across labs. In a lot of the studies that I was initially doing, I was finding general emotional memory enhancements with aging that often weren’t that different than what younger adults were experiencing. But around the same time, Mara Mather, Laura Carstensen, and their collaborators were reporting positivity effects with aging, where older adults were actually remembering more positive experiences than negative experiences. So that just really piqued my interest to try to understand: When are we seeing more general emotional memory enhancements and when is there something that is a pull toward the positive, the older that we get?  

I’ve become really interested in what happens to memory when young and old experience the same public event or see the same set of recorded events. What are the details that people pull out from that complex event? What’s the framing that they give to past experiences? We’ve seen over and over again now that the older we are, the more likely we are to put these positive spins on events; that is, thinking about the silver linings of past events or noticing these little positive moments in a complex mixed emotion event. Whereas when we’re younger, it seems like we’re much more likely just to hone in on the negative. That’s something that is so important for understanding some of the generational differences that exist. We can all ostensibly have experienced the same event, but what we’re holding onto and how we’re thinking about that event, and what we’re learning about that event, might actually be quite different if we’re 20 versus 70. 

MARTIN: What is the basis of this positivity effect in older adults? Is it motivational or, perhaps, something about the way the hippocampus works differently with age?  

KENSINGER: Maybe the most obvious explanation would be that it is something about biological aging that is making negative events less salient, but that explanation has been pretty firmly ruled out. It turns out, mainly from work by Mara Mather and her colleagues, that it’s really the older adults who have brains more like younger adults that show the highest positivity effects. These findings have led people to think that the positivity shift may be more motivational, but there are still a lot of questions about what those motivational shifts are. We have found that the older we are, the more likely we are to recruit a portion of the frontal lobe – the dorsomedial prefrontal cortex – to reduce the negativity of a memory and even to focus on the positive aspects of a complex event. A hypothesis is that these age differences relate to the relevant memories that we can rely on to help us understand and contextualize the event. Take the lockdowns with the COVID-19 pandemic – that was novel for all of us, but probably if you’re 70 or 80, there were other times when your life suddenly looked very different than you had expected, whereas that may not have been the case for younger people. So, older adults probably did have other memories that they could rely on. They had some ability to predict that this, too, would end and things would eventually be more normal. But if you’re 20, you don’t have those memories, so you don’t have that ability to use them. I think it’s easier for younger people to just get stuck in the surprise and often the negativity of a moment. To me, that might be different than a motivational shift. It might be an age difference in how we are able to use our memories. 

MARTIN: Let’s discuss a few more recent topics you’re investigating. I saw some recent work on sleep and its role in memory formation. Could you say something about that? Are you looking at sleep disorders? 

KENSINGER: If we’re not sleeping well, obviously lots of things go wrong for us. However, memory is definitely one of those things that goes wrong when we’re not getting high-quality sleep. That can be for extreme reasons, like we have untreated sleep apnea or are suffering from insomnia, but it can also be because we are not prioritizing our sleep and we’re chronically restricting the amount of sleep we get. It can be that we are having one more glass of wine than we should be having and it’s suppressing sleep in the second half of the night. So, there are lots of reasons, especially in modern culture, why we’re not getting high-quality sleep. Our work and that of many other groups has really suggested that, while that’s bad for memory in general, it also seems to really disrupt the ability for sleep to prioritize memories that are likely to have future relevance. 

There are many reasons why an event that we experience might have future relevance, and emotion is just one of those. But sleep does tend to play a role in this ability to hold onto those memories that have some future importance for us and potentially to also play an active role in helping us forget some of the more mundane moments from our life. That is, sleep seems to be involved in why we can’t remember what we ate for lunch last Tuesday, but we can remember what we ate for breakfast this morning. Over time and over sleep, we’re pruning some of these irrelevant details. 

MARTIN: Very interesting. Your recent work has also looked at the relationship of sleep to memory in terms of depression and anxiety symptoms. Could you say a little about that? 

KENSINGER: We’ve been interested in understanding how emotional memories look different in individuals who have higher levels of depressive symptomatology or anxiety symptoms. Much literature has shown that negativity biases in memory are prevalent in individuals who have depression or anxiety. But even in healthy individuals who don’t meet the diagnostic criteria for those disorders, we have shown that the more symptoms you show for depression or anxiety, the more likely you are to have some of these negativity biases; the more likely you are to have these memories that zoom in on the negative details and miss some of the other elements of the experience. You also can be more likely to have sleep selectively emphasizing some of these negative aspects, although in a recent study with Jessica Payne, we also found that sleep may protect against some of the disruptive effects of anxiety symptomatology on memory (Niu et al., 2024). 

MARTIN: It’s a common assumption, too, that older adults have sleep problems. They sleep less and sleep less restfully, waking up more often. 

KENSINGER: It’s still a very young field of study, but that’s something that Jessica Payne and I have recently started to look at. So far, we’ve been focusing more on looking at young versus middle-aged adults. By age 30, you’re already starting to see some large shifts in sleep. And a lot of the research on sleep and memory has typically excluded anyone over the age of 30 or 35. This means that for most of society, we don’t know as much about how sleep influences memory. We’re slowly starting to chip away at this by including middle-aged adults in our studies of emotional memory. It is really important to keep in mind that the older we get, there are reductions in slow-wave sleep as well as a number of other reasons why we’re waking up more in the middle of the night—we have more pain, we may need to use the restroom more. All of these things can lead to fragmented sleep as we get older. And there certainly are ramifications from that. It will be no surprise that some of the age-related changes in emotional memory that we see are tied to age-related declines in sleep quality, because we see that association in younger adults. 

MARTIN: I didn’t realize it was such a new field to be looking at the effects of sleep on memory in older adults. 

KENSINGER: For the emotional memory piece, it definitely is. There’s a reasonable amount that we know about sleep and aging in general, and some about the consequences for memory, but much less we know about sleep, aging, and emotional memory.  

MARTIN: We’ve talked about some recent research. Could you speak a bit about your directions for the future? 

KENSINGER: What has excited me so much about the study of emotional memory is that there are so many different factors that all become relevant. We’ve talked about the role of sleep, we’ve talked about the role of aging, and we’ve talked about the role of depression and anxiety symptomatology around that. So far, what my lab has done is study each of these more or less in isolation. That initial work was critical. We had to lay that groundwork first. But now, starting to be able to build up from there to actually look at interactions when you have multiple of these variables that you’re looking at, at the same time, is going to be critically important. What happens as you think about an emotional event multiple times, including over a night of sleep? How do the recalled details change over those repeated retrievals? I’m really interested in what it means when we have intergenerational communication after an emotional event. If a younger and an older adult talk about the COVID-19 lockdowns or talk about the U.S. presidential election, how does that shape our memories, given that we know that young and older adults are oftentimes remembering different content or framing events differently? I’m really curious in understanding those sorts of real-world implications for some of these age-related differences that we’re seeing. 

MARTIN: That’s great. All of this will be fascinating to the general membership of our society, which includes social, personality, developmental, health, clinical sciences—all the various areas of psychological science. It seems like your work touches on many of these areas. So, I’m very glad you’re giving one of our keynote addresses! 

Talking about real-world applications, you recently published a book with Andrew Budson titled “Why We Forget and How to Remember Better: The Science Behind Memory.” Do you have a couple of tidbits to share with us? 

KENSINGER: Sure. A lot of the book is really about the core principles of memory, things like the importance of focusing your attention on what you’re trying to learn and not multitasking in trying to do three things at once and getting enough sleep. For retrieval of memories, we focus on trying to point out common mistakes we make. For instance, I’m still guilty of this where I’m trying to generate someone’s name and I start thinking of all the possible names that it might be, even though I know that’s a terrible strategy and I shouldn’t do that. We try to explain to people how generating all these possible names can block our own memory retrieval, and why being anxious is so bad for memory retrieval. There’s a reason that “why” is in the title. We want to help people understand why it’s so important when you’re having that momentary retrieval failure to take a deep breath, to try to stay calm, to think about something you know about the person, rather than going through this frantic generation of possible names. 

MARTIN: Oh, that sounds great. I’ll have to get a copy. It’d be good to be able to share these ideas with students. It’s been great talking to you. Thanks for taking the time. 

KENSINGER: My pleasure. 

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