Brain & Body: How the Body Shapes the Mind

In this episode, I speak with Professor Camilla Nord from the University of Cambridge about how the brain and body shape our emotions, motivation, and mental health. We explore the science behind how these systems work together in everyday life.

Transcript

SPEAKER_01 0:12

Welcome to the Unfiltered Bloom Podcast. I'm Isabel Rhode and in today's episode we're exploring the science of the brain-body connection. This is something many students and young adults experience every day, whether it's stress before an exam, feeling emotionally overwhelmed, or wondering why our bodies can influence the way we think and feel. I'm joined today by Professor Camilla North, Professor of Cognitive Neuroscience at the University of Cambridge and leader of the Mental Health Neuroscience Lab. Her research explores how communication between the brain and the body shapes our emotions, motivation, resilience, and mental health, and how these discoveries can help improve treatments for conditions such as anxiety and depression. She is also the author of The Balanced Brain. Before we begin, I'd like to briefly introduce Unfiltered Bloom. I'm Isabel Rhodes, I'm 16 years old and the founder of Unfiltered Bloom, a nonprofit podcast that brings science to life through real conversation with experts in psychology, neuroscience, biology, and personal growth. Our goal is to help young people understand how science connects to everyday life. Hi Camilla, welcome to the Unfiltered Bloom podcast. Thank you so much for joining me today. I think many people have experienced feeling anxious or stressed for no obvious reason. Even when everything around us seems fine, those feelings can still appear. Why does that happen?

SPEAKER_00 1:52

So there are a lot of reasons why our brain can evoke these kinds of stress or anxiety responses even outside of an immediate context. Obviously, our brain has evolved in part to deal with the present situation, but it's also, I would say, its main purpose is to predict and potentially avoid, if it's bad, future scenarios that might cause that kind of stress or anxiety. So as a result, that kind of predictive function of the brain is one reason why you might feel stressed or anxious despite it not being relevant to your present scenario. It's because your brain has perhaps developed some kind of prediction model that means it's anticipating, whether rightly or wrongly, stress and anxiety. The same thing can actually happen, I should say, although it's predicting the future, it might be drawing on the past to do that. So it might be that something has reminded you of the past. But what the brain is really trying to do is to prevent something negative happening, and that might instantiate these kinds of feelings even outside of like the present necessity.

SPEAKER_01 2:58

That's really interesting. I hadn't realized that anxiety could come from the brain anticipating what might happen next. So moving to the body, your research shows that it plays a major role in how we feel. But how much of our emotions come from our body rather than from our thoughts?

SPEAKER_00 3:18

Well, you know, the story there is that over the past maybe two decades, there's been a resurgence of interest in the role of the body in how we feel. Not just me, but actually many other people, many other scientists have kind of formed this opinion that in fact the body is very influential over how we feel, but not maybe in the way that much older 20th century experiments thought about it. Instead, the way that we think about it is the body helps inform the model that the brain is currently using. So in the example you just gave me about stress and anxiety, the body might be feeling like let's say ambiguous, heightened physiology. So it might be feeling things like an increased heartbeat, you might be having changes to your blood pressure, to your respiratory rate, but all of those changes can be interpreted in lots of different ways by the brain. And we've known this for a long time in psychology that identical bodily states can be interpreted in different ways. And actually the same is also true in a top-down sense. So what the brain is expecting to feel can actually modify the physiology itself. So there's a kind of two-way path there between what the body is doing physiologically, how the brain is interpreting those signals, and then output that the brain is sending to the body, which might change the nature of the signals themselves. So in the field of interception, which largely means the brain's interpretation, perception, and prediction of signals from the body, we've discovered that many emotions have key components coming from the body, even those you wouldn't expect. For example, my lab has shown that the rhythm of your stomach, sort of your gastric state, seems to influence your ability to avoid disgusting things. Why would the stomach have anything to do with disgust? Well, it's entirely possible that the way our brain has learned to avoid things that make us sick, things that make us nauseous, is by listening to signals from the stomach and changing its activities or behavior accordingly. So I think all that is a kind of long-winded way of saying that there's very clear evidence for the role of the body in emotions, but never as a singular input, never as in this is a single bodily state that can only mean this one thing, and our brain doesn't have to do anything except listen. Indeed, our brain is always doing more than listening when it comes to interpreting signals from the body, but even also when it comes to seeing or hearing in the outside world.

SPEAKER_01 6:01

Yeah, that makes sense. So why do we sometimes struggle to find motivation, even when we know we need to get something done?

SPEAKER_00 6:10

I'd really like to understand the answer to that question as well. So we know that people are able to sort of cognitively estimate how difficult something is and how important it is, and all sorts of things like that, but sometimes are just not able to create the right kind of effort in the right place to do that activity. And there can be lots of reasons for that. Um one of the reasons that we study the most is called anidonia, which is a lack of pleasure or motivation to engage in the things you would normally engage in. So if you're someone who typically loves um swimming and hanging out with your friends and eating lovely desserts, then in a period of anedonia you might lose the desire for these things. And that desire often manifests as the motivation to actually do something to get those things. You know, you might still, if somebody handed you one of them, do it, but you wouldn't actually do the difficult things on the way to getting any of those, the motivation. Um, so the reason this might happen is because of a number of different brain changes, um, many of which uh have been attributed to the dopamine system in the brain, one of the brain's main chemical neurotransmitters, and some functions of the dopamine system, not all, have to do with this motivation to be able to engage in these sorts of activities. Um, it's not the only source, but that's one of the things many people are exploring. Um, there's also a relationship between information in the body and information in the brain in making this computation. So, for example, in times where maybe you don't have a lot of energy resources in the body, you wouldn't actually want to engage in difficult things. Your brain shouldn't, because it needs to conserve energy. So, one of the ideas we've put forward in my lab is that actually these energetic differences might change your motivation in and of themselves. So, we found, for example, um, differences in the way you make effort-based decisions in diabetes. So, perhaps there's a kind of change in the way the brain tries to conserve energy rather than expending energy.

SPEAKER_01 8:22

Okay, that's interesting. I'd now like to talk about burnout because it's something so many students seem to experience. What's actually happening in the brain and body when someone experiences a burnout?

SPEAKER_00 8:35

We don't actually know the answer to that question. It could be that burnout is a bunch of different things, not always a change in motivation, like what I've talked about, because sometimes burnout happens following a period of very intense motivation. Some people would even argue that there are components like the inflammation system in burnout. So sometimes people who experience viral changes, say following an infection, might be more likely to experience symptoms that are kind of like burnout. So it's actually a really unknown area, and it may be that it has uh kind of sources from a bunch of different fields.

SPEAKER_01 9:21

I didn't realize we still know that much about burnout, but my next question is why do we sometimes know exactly what's good for us, but still end up doing the opposite?

SPEAKER_00 9:32

A lot of people find themselves um in this conundrum. Um, one reason could be that the things that we want to do right now are associated with no temporal delay, so no amount of waiting, which humans really don't like, and the things that we know are good for us that might be nice in the future involve waiting a really long time. So, even sort of effort or unpleasant behavior aside, just the wait is really unpleasant to people. People don't like being bored, people don't like waiting for something very far in the future. And it sounds silly, but it's actually very adaptive because if things in the future had as many rewards as things today, it means you're assuming no changes at all by that future point. Let's say I promised to give you a pound today or two pounds in 50 years. You should actually probably choose a pound today because you don't really know what's going on 50 years from now. Have we actually moved to the euro? You know, we you actually don't know the context in which you're accepting those two pounds because it's so far in the future. Therefore, you do a thing called temporal discounting, and so your brain probably tells you to take the pound today. But there are lots of intermediate places where some people might take a pound today and some people might actually wait two weeks to get a little bit more money. That's probably a more adaptive thing to do. Um, but people will have sort of different set points for this, and that's attributing it all to sort of one thing, but actually it's not the only mechanism by which you might or might not wait for a reward, or you might or might not be able to do something difficult to get a reward. We've already talked about effort-based decision making or the ability to motivate yourself through something unpleasant. And there are also other ways of thinking about it. You know, how much do you value particular rewards, social rewards versus monetary rewards versus other kind of rewards? How much do you weight potential negative things happening? Maybe you're somebody who really overweights negative things happening, and so actually the effort you're willing to put in is to avoid that negative thing, but you're not as motivated by potential positive things happening. So those are just some examples of ways in which your brain might work slightly differently from someone else's brain that could lead to these discrepancies.

SPEAKER_01 11:58

I think a lot of students can relate to that, knowing what the better choice is, but still struggling to make it. So why do we sometimes overthink conversations or mistakes for hours, even when everyone else has already moved on?

SPEAKER_00 12:13

So one of those reasons is because we all have a kind of bias towards thinking about ourselves, not in a selfish way, just in a we need to learn things about ourselves and the world around us. So, in a way, it makes sense to overfocus on these things that might have happened to us compared to things with other people, where you can kind of write it off or easily see how randomness could have caused them or other things like that. So I think that's a kind of key reason. And then a second one is that often the things that have happened to us are genuinely more socially important for us than things that are happening to other people? So you focus um not necessarily because you have to, but because you might have to, if that makes sense. There's a bit more about um the potential importance of this information, even if it's not, um, if it doesn't turn out to be very important.

SPEAKER_01 13:10

So if our minds can keep us stuck on certain thoughts, can changing the body through better sleep, exercise, or even the way we breathe help change how we feel emotionally?

SPEAKER_00 13:22

I would say almost certainly, yes. The problem is we don't always know exactly how. So there's a good debate about exercise. Some studies show, big studies, like epidemiological studies, population studies, that means, um, that exercise is very strongly associated with positive mental health. So if you look at those studies, you're like, yeah, yeah, I should definitely work out for my mental health. Then even if you look a little more deeply at those studies, you go, okay, the kind of picture gets a little complicated because there's certainly such a thing as exercising too much for your mental health in those studies. People who exercise really quite a lot, it does they don't seem to have better mental health. Possibly they have slightly worse mental health than everyone else. And then it gets even more complicated if you look at what I would consider the most robust studies to answer that question, which is if you give someone exercise, if you make them do exercise compared to something else, is that necessarily beneficial for their mental health? And then the answer tends to be it depends what the something else is. So there are many things that could improve your mental health. And sometimes the things that people choose as a comparison to exercise are actually also helpful for your mental health. And sometimes that's because that thing is itself a bit physiological, like breathing, but sometimes it could just be because that thing is actually quite fun. And so you're bringing other bits of enjoyment back into someone's life. So basically, my answer is yes, that these various physical interventions can have positive effects on mental health, and to a degree. Often there are cases where you wouldn't want to only suggest interventions like that because, for example, someone might be very unwell and so actually might need more medical interventions. But there are other cases where it's sort of like actually fixing these aspects could have a genuinely very remedial effect on someone's mental health, especially, I should say, sleep. Sleep is hugely significant to everyone's mental health. And many people who experience poor mental health, it immediately comes along with poor sleep, and at least they report that should the sleep be fixed, they would then experience better mental health. You never know exactly the direction of causality there.

SPEAKER_01 15:37

Yeah, sleep is clearly so important, and I think something many students and young adults struggle with.

SPEAKER_00 15:43

Yeah, definitely. And I would say one way that um sleep is a very unhelpful thing to cite is that actually thinking about how much you need sleep for your mental health is the worst thing you can do when you're trying to get to sleep. Do you know what I mean?

SPEAKER_01 15:57

Yes, absolutely. Sometimes the pressure to sleep well can make you even more awake. With that in mind, what's one small science-backed habit that young people could start today to improve their mental well-being?

SPEAKER_00 16:13

So, one of the things I think young people could think more about is circadian rhythm. That means do what's best for you at the right time for you. So, if you, as a young person, have a shifted circadian rhythm, okay, you might not be allowed to go into school late because that is a structure imposed by society, though it is something researchers are testing to see if teenagers, for example, would do better with later school times. Um, but you may be able to optimize when exactly you do your revision, doing it at times where your brain is working well for you, which might be in the evening versus in the very early morning if you're somebody with an early shifted circadian rhythm. So we've found that people are able to put in more effort and are willing to make more effortful decisions at the time that is compatible for their chronotype. You know, if you're an early bird, if you're a night owl, many people are in between, but especially those people at the extremes. And this really makes a difference because it means that you can put in more effort, you often emotionally feel better, but also then the outcome is often better if you do this, taking into account your own circadian rhythm.

SPEAKER_01 17:32

Yeah, I can definitely relate to that. I've noticed that I focus much better when I study in the afternoon or in the evening than early in the morning. So if you could change one myth about mental health that you often see on the internet or social media, what would it be?

SPEAKER_00 17:50

For me, the myth I would change is that there is a really clear dividing line between biological and social routes to mental health or to help mental health. This is actually the whole reason I wrote my book, which is called The Balanced Brain, The Science of Mental Health. I wrote it, and it's for a public audience, it's for young people, it's for older people who are interested in mental health, because I felt there was not just a stigma associated with mental health, but also a misunderstanding that things that happen to your physical body are totally distinct from things that happen to your mind. And in fact, that even within things that happen to your mind, you might want to take an antidepressant if you personally believed in a biological cause, or you might want to go see a therapist if you personally think there was a social cause to whatever you were feeling. But actually, the brain doesn't differentiate at all. The brain is a biological organ that is affected every day, day in, day out, by social experiences. So actually, when you do therapy, there are biological changes that happen to your brain. When you take an antidepressant, there are changes in emotional and social things happening in your behavior. So both types of biological and social interventions are happening to the brain. I also feel that there is sometimes an artificial separation between mental and physical health, meaning if you're experiencing physical symptoms, it must be coming from somewhere in the body. And that's really wrong. There are many great pieces of evidence for why that's wrong, but it's also important in understanding your own mental health, which might sometimes manifest as physical symptoms. And so, yeah, that's sort of the thing I would most want to change is this kind of mental versus physical division, which co-occurs with a kind of social versus biological division in mental health.

SPEAKER_01 19:51

That's such an important point. The mind and the body are much more connected than people often realize. To finish, if you wanted listeners to take away just one message from today's conversation, what would it be?

SPEAKER_00 20:06

So the single message I think that's most important is that there isn't a single route to bad mental health, to poor mental health, and there isn't a single route out. Rather, there are kind of many different pathways that could lead to poor mental health, but they converge on the brain. And the very many pathways out also all rely on changes to the brain. And understanding those changes could be really key to helping your mental health.

SPEAKER_01 20:35

That was very helpful. Thank you so much, Camilla, for joining me today and for sharing your knowledge and insights with us. It was such an interesting conversation. That was my conversation with Camilla about mental health, emotions, motivation, and the fascinating connection between the brain and the body. I hope you enjoyed this episode and learned something new. If you enjoyed this conversation and don't want to miss future episodes, make sure to follow Unfiltered Bloom. Thank you so much for listening, and I see you next time.