Why does it hurt so much to lose someone you love? What happens in your brain as it strives to cope? Pioneering psychologist Mary-Frances O’Connor worked on one of the first neuroimaging studies of grief more than two decades ago. She and her colleagues found that a loved one’s absence means a major disruption not only to our life but also within our brain.
O’Connor now runs the Grief, Loss and Social Stress (GLASS) Lab at the University of Arizona, where she tries to tease out the biological mechanisms underlying grief. In particular, she studies prolonged grief, a state in which people don’t seem to heal, instead staying immersed in their loss for years. In her book The Grieving Brain (HarperOne, 2022), O’Connor explains how insight into brain circuits and neurotransmitters can enable us to navigate bereavement with self-compassion. “Grief is the cost of loving someone,” she writes. When a loved one dies, it can feel like we’ve lost a part of ourselves because their presence is coded into our neurons.
Spektrum der Wissenschaft, Scientific American’s German-language sibling publication, spoke with O’Connor about how love permanently changes our neural wiring and what we can do to feel more like ourselves while our brain tries to update its understanding of the world when a loved one is gone.
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People who have lost someone often feel like their beloved will walk into the room at any moment, or sometimes they think they’re seeing the person on the street. Why does that happen?
It’s not perfectly worked out yet, but I have what I call the gone-but-also-everlasting theory. We think of the brain as a single entity, but there are many systems in it. On the one hand, you have the memory system, in which, say, we have a memory of being at the bedside or at a funeral. So one stream of information in our brain understands the reality of our loss and can remember that happening. But there’s another stream of information in our brain, and that comes from attachment neurobiology.
To understand what happens during loss, we first have to think about what happens during bonding. When that relationship is created, that bond is encoded in the brain in very specific regions and very specific ways. It comes with a belief that “I will always be there for you and you will always be there for me.”
That is the nature of a bonded relationship. It is what makes us know our partner will be at home when we return after work or enables us to send our children off to school—we know that they will return to us and that we will seek them out if they, for some reason, don’t turn up. The belief that they are out there in the world, even if we can’t see them or hear them, works very well when our loved ones are alive.
That attachment neurobiology, that belief in the everlasting nature of the bond, does not change immediately when a loved one dies. That second stream of information is still telling us they’re out there. We should go find them because they are missing, because they are lost. And so those two streams of information—the memory of the reality on one hand and, on the other, this belief that they are out there—cannot both be true.
Our brain really struggles to understand what has happened. And when we become aware that we have both beliefs, it causes a lot of distress and grief.
In your book, you also write about the brain as a prediction machine. When it comes to bereavement, is the brain making wrong predictions?
Predictions happen at a lot of different levels, because usually our relationships with our loved ones are multifaceted. So the brain is predicting, as I just said, that our loved one is out there, and it is sort of motivating us to go seek them out. It has difficulty learning to predict their absence. If you’ve woken up next to someone for thousands of days, and you wake up one morning, and they’re not there next to you in bed, it’s actually not a very good prediction that they have died, right? Our brain would much rather believe, “Oh, they’re on a trip, or they’ve gotten up early today, and they’re just not here right now.”
In fact, over time we have to change our prediction to understand that they will not be next to us on any day in the future. But those are not the only predictions that we have to cope with. There’s also a level of simple habit when we live with someone or when we have a relationship with someone. We predict when we will interact with them and in what way we will interact with them. So, for example, you’re at the grocery store, and you pick up a soy milk because your daughter is lactose intolerant. It’s not a conscious decision. It’s just an automatic habit. But if your daughter just died, you may for some time pick up soy milk even though no one is drinking soy milk in your home any longer. So even at the level of habits, we have to constantly be confronted by all the changes caused by the loss of this important person in our life.
How is the presence of a loved one hardwired in the brain?
I would say they are not hardwired into our brain; rather they are in the wiring of our brain. So when we fall in love with our baby or we fall in love with the person who becomes our spouse, it changes the wiring. It updates the physical connections between neurons, and it changes the way that proteins are folded. The epigenetics [environmental and behavioral influences on the ways in which genes are expressed as proteins] of our brain change because we have fallen in love with this specific person.
Those physical traces in the brain have to be changed to reflect an updated understanding of the world, and that takes time. But it also takes experience. We have to have many, many days of being in the world without our spouse or our child or our best friend for the brain to create new connections and a new understanding of what it means to be without this person.
The general principle that this is how the brain works comes from Nobel Prize winners Edvard I. Moser and May-Britt Moser, who discovered what they call “object-trace cells” in the brain. They did experiments where they would take a rat and put it in a little black box every day. And then one day there was a blue tower inside the black box. The rat went to visit it, and because they were measuring single neurons firing, they could see that there were specific cells, [called object cells], that were firing as the rat investigated this little blue tower. And one day they took the blue tower away. For many days, even in the absence of the blue tower, [other cells that evidently tracked absence, the] object-trace cells, continued to fire because the rat expected that there would be a blue tower.
What’s amazing about this, of course, is that a blue tower is not very important in the life of a rat. Think how much more important our loved ones are in our life and how many more ways they influence us. We can’t do single recordings of single human neurons, but the general principle can be applied to grieving. We have to change the way our our neural networks are firing to understand our new reality.
What role does closeness play? The closer we are to a person, the more, of course, the loss hurts.
It seems that “closeness” is a dimension we use to predict what our interaction will be like with a loved one when we see them. In the same way that we can predict the time and place we will see our loved one, we can also predict the closeness we will feel with them. If I said to you, for example, “Where is your partner?” or “Where is your child?” you probably would be able to give me almost an immediate answer. Those dimensions of time and space are a way that we keep our loved one’s presence in our mind. In a similar way, we keep a sense of how close we are to them in our subconscious mind.
So, for example, we will often think of them when we’re doing something stressful as a way to soothe ourselves, even if they’re not present for us in that time and space. Just thinking about our closeness with them changes our stress response. Just as our brain cannot really understand the abstract idea that our loved one is no longer in time and space, it continues to expect our loved ones to respond to us. The fact that they don’t respond to us..., in an illogical way, can feel like they’re ignoring us. So I think people who are grieving too often feel overwhelmed with anger with this person for dying, and they know that is completely illogical. But the feeling is that if we are close to them, they should be responding to us.
When we’re grieving, the feelings we have, the thoughts that we have, even some of the things that we do—we feel like we’re losing our mind. But if you understand why your brain might be reacting this way, I think it gives us a little patience with ourselves. Grieving is a form of learning. And learning takes time and experience, and our brain is doing its best to help us. But it’s going to take some time.
You did the first neuroimaging study of grief in 2003. What did you find out?
When I began studying the psychology and neuroscience of grief, the primary way that researchers were thinking about the loss of a loved one was in a stress framework, the idea being that this is an incredibly stressful life event, and we respond to that stressful life event by coping with it. It was very much this idea of “you have so many things to cope with. And here is another thing on your plate that you have to cope with.”
Because of some of the research I’ve done, we discovered that when we have a bonded relationship, it is encoded in the reward network of the brain. The reward network is motivating us to seek loved ones out and to enjoy them as we did when we were with them. That is how researchers now think about grief—as having had something taken away from us, from our sense of self, rather than having something added onto our plate. And this is a pretty big difference in thinking about how grieving works.
When people say, “I feel like part of myself is missing,” this may not be only a metaphor. It may in fact be part of how the brain has encoded that relationship, so the absence of that person is like an amputation rather than simply an additional stressor.
People usually say that time will heal all wounds. Is this also true for grief?
Yes but with caveats. Grieving can be thought of as a form of learning—learning that this person is really gone, learning to predict their absence, learning what it means to be a person who has grief or to understand our own identity as a widow instead of a married person, for example. Then it requires not only time but experience. So, for example, if you were in a coma for a month after a loved one had died, and you woke up to hear the news, you would be having the same grief reaction as before the coma. It’s not time specifically that helps us to adapt; it’s about having new experiences in the world and allowing our brain to understand what life is like now.
Because it is often very painful to be in the world, to see old friends or to go to a place where you spent time with the loved one, we often avoid those experiences. But in many ways, those are exactly the experiences that our brain needs to learn how to understand the world now. And so in psychotherapy, often we enable a grieving person to tackle some of these things they’ve been avoiding so they can learn new skills—how to allow a wave of grief to come but to also allow that wave to recede so they can continue to do meaningful things in life or to have relationships with living loved ones.
What are the typical emotions people will experience, and where do they come from?
We have a much wider range of emotions than any of us expect when we are grieving. They include, of course, sadness and yearning. But they also include anger and blame and guilt and other things as well, such as panic. When we are separated from a loved one, we feel panicky. If you’re in the grocery store, and you look down, and your toddler is not next to you, you feel this panic. People who are grieving often describe a sense of panic as well, because we expect our loved one to be there, and our natural response to their absence can be to feel panicky.
But grief is not only an emotional response. We have a physiological response as well. Our heart rate usually goes up a little bit. Our cortisol stress hormones increase, and these often make it difficult to eat or to sleep. All these changes can make us very off-balance, can make it difficult to concentrate or to remember important details in our day-to-day life.
Is grief only about the loss of a loved one, or can it also come from other losses?
Where do we start? We know that for social mammals, attachment bonds are as vital as food and water to our survival. Because you are a human adult, I know that you had an attachment relationship that enabled you to survive to adulthood, which required you to be bonded with someone who cared for you. It is for this reason, I think, that our brain evolved mechanisms to create attachment bonds and to adapt when those bonds are broken. And obviously the most concrete example of breaking those bonds is through the death of a loved one.
But human relationships are broken for many reasons, whether that is a divorce or the “empty nest” when our children move out into the world or simply becoming estranged from a very close friend. These breaks change that bonded relationship so that we can no longer rely on the belief “I will always be there for you, and you will always be there for me.” And so, I think, we experience these other disruptions in relationships as grief as well.
And grief is not only about the loss of a person. We have grief over the loss of many things—the loss of health, the loss of a job. Our brain might have evolved to understand the loss of a relationship as grief, but it’s always also a loss of a part of ourselves. Even the language we use is helpful here. I describe myself as a daughter—that’s a word that I use about me. When I lose a parent, it is a loss of an aspect of myself. Similarly, the loss of eyesight is the loss of how I function in the world with my eyes.
In a study some years ago, we found that the severity of yearning was greatest with bereavement and somewhat less with a breakup, but they were still the same qualitative experience. Of course, there are other things that impact breakups. If the other person initiated it, the yearning was much greater than if the griever had initiated or if it had been a mutual decision. Grief operates differently in these different types of losses but shares a common experience.
Some people have a much harder time coping with the loss. Why is that?
We know from really detailed studies that although there are similarities across the way people grieve, not everyone has the same experience in grieving. For most of us, the waves of grief become less intense and less frequent over time. But for perhaps one in 10 bereaved people or even fewer, for many, many months, they don’t show any change in their grief reaction. They still seem to be responding the same way they did right after the death happened.
We call this state prolonged grief. Most people continue to feel waves of grief for years after the loss of someone important, but typically their grieving starts to change within a year. For a few people, there is no change. It’s important to identify them because psychotherapy can help them overcome some of these barriers that are preventing them from adapting.
There are some predictors for prolonged grief, and they include things such as preexisting mental health difficulties and having very little social support. Being very isolated also seems to predict poorer outcomes in grieving. We have a lot to learn about what individual variation in the brain leads to prolonged grieving, but the science is very much in its infancy.
People who lost somebody will often, out of nowhere, have thoughts about the person. Where do they come from, and are they good or bad?
People are often very shocked by the intensity and frequency of these intrusive thoughts. There are a few things to know that can help you to feel more normal in the midst of these thoughts. One is that we actually have intrusive thoughts all the time. Another thing is that when a loved one is alive, thoughts about them just pop into our head. Our mind sends us push notifications like “don’t forget that you have to pick up your daughter at sports and not at school today.”
It’s just that after they’ve died, the same intrusive thoughts are very distressing to us. The context in which they’re happening is very different now and very painful. Intrusive thoughts can also lead us to ruminating—we keep going over it and over it, and we can’t seem to let it go. One of the really common experiences that people have, a very natural and normal response, is the “could” or “should” thoughts. These are the million stories that we play out in our head where something could have gone differently. We should have gotten them to the hospital sooner or to the doctor.
For many grieving people, these stories go around and around and around in their head. And the challenge is that our brain can come up with an infinite number of these alternatives in which, if something was done at the right time, “my loved one would have lived.” But the only reality that we are currently dealing with is the fact that they did not live. These thoughts are quite natural and normal and common, but they don’t help us to adapt to what’s happening now. Many people come to realize that there is no way through these thoughts; rather they have to find a way around the thoughts and allow them to recede.
How does understanding the neuroscience of grief help people navigate this lonely landscape?
Neuroscience can give us some insight into why we feel such pain and how and why the brain is making that happen. I think it can make us feel more normal that our brain is on a learning trajectory. And we simply have to accept that things will be difficult for some time while our brain tries to update its understanding of the world. But it’s also very comforting to understand how. When we have this loving relationship with someone, it means that our brain is permanently, physically changed. What that means is even after a loved one has died, they are still physically with us. They are still in those folded proteins and neural connections. And there’s something, to me, very comforting about knowing that my mother or my father still lives in me physically.
This article originally appeared in Spektrum der Wissenschaft and was reproduced with permission.