A conversation between Matt Fratson and Simone Kühn, Psychologist and leader of the Lise Meitner Group for Environmental Neuroscience at the Max Planck Institute for Human Development, Berlin, 20th November 2023.
Matt
I’ve been waiting for a long time really to be able to talk to someone about the relationships between climate health and cognition, and I’ve been talking to archaeologists and geologists a lot over the past couple of years about land loss, erosion, environmental degradation, but I haven’t really had the chance to talk about shifting environmental baselines with somebody working in psychology or neuroscience. I’m really keen to learn a little bit about what you are working on at the moment?
Simone
I come from a field where we usually run intervention studies. When I first studied, it was still the credo in psychology that the brain is as it is when we are born, and it just increases and declines. Over the course of my studying I learned that this was not true, so that we can regrow brain regions or at least neurons in some part, and I was curious to see: could we come up with interventions to show how something might make certain brain regions grow. And I’ve invested a lot of time trying to find out what kind of things these might be, and we have found a lot of them - I mean you really can advise people on what to do if you want to make your brain grow! But on the other hand, people just don’t do this. Even with video games, people stop training once the intervention is over because the people that we recruit would commonly not be video game enthusiasts, which is fine to stop but something that we need to accept I think. So I’ve been thinking if we knew better how the environment shapes the brain – as it is, before even thinking about climate change, then we would at least know what kind of ingredients we need for a healthy brain, let’s say. What we would like is something that could reach a lot of people easily – I mean this is never easy, but if we knew for example you might need a certain amount of trees around you or this much opportunity to see the sky, then you could just try and take care of this in a sense, without having people even engage in anything really. And now, what we do is basically different types of studies from very short term interventions where we might tell people ‘go for a walk now’ and we study brain function before and after – we also try to utilise existing data sets, which we can correlate where people live with how they feel, and what their brain looks like, which is difficult because this is the study of almost everything! But you need to start somewhere.
There are some differences in the field, like the psychiatry literature very much looks at the detrimental aspects of urban living – they are really convinced that there is something bad about city life that makes people mentally sick, whereas environmental psychology in my opinion really looks at how green spaces or natural environments can enhance mental health – which is a different story I would say - I mean it sounds like the same thing but it’s a very different point of view, and I have to say that all the data that we’ve gathered so far argues rather in the direction of nature having positive effects than of urban areas really having negative effects. If so, we rather find some elements of cities being good, for example if you look at cognition, we really have an extensive cognitive battery in an ageing study, and in ageing it seems to be good again to live in very densely populated areas, at least for cognition. It could also be that people select into this, I mean you never really know what selective migration does, right? But my thinking somehow is that as you age, some kind of stimulation might actually be good, and being forced to continuously multitask, to do things in parallel – just more input on a regular basis.
We also try to use virtual reality, which is useful because of the amount of control it gives you, and where you can just make small alterations to small aspects – there is something beautiful about this, for nature studies as well as for interior design or for architecture, because you can alter exactly what you know you want to change and nothing else. However, I sometimes have the feeling that the results look different still, I mean we have done some studies where we just took pictures out of our virtual reality spaces and then showed these pictures to people, and that makes for very different results compared to putting them inside of the virtual reality experience. It makes me think - by now I quite strongly believe, in the fact that people can look at their surroundings in two different ways – they can look at it as if it is real, and they are just there, or they look at it in some kind of aesthetic way, as if it was a picture on the wall. And then again if you really imagine being in a forest, and you really feel that you are there, it’s a very different thing to looking at a picture of a forest, which might be aesthetic but for some people there might be parts of nature that you actually don’t really appreciate while still having a romantic view of things. We have some slight problems here with comparing studies that just use pictures, compared to those where you simulate that somebody is somewhere else, or when you actually send people to those places. That’s why we are trying out these ideas at many different levels. I’m not sure how good we are yet at integrating the findings but my overall impression is that the positive effects of nature are outweighing the negative effects of cities. We are really just at the start of understanding environmental causes let’s say of mental wellbeing, and there’s still a lot of work to do before we reach any conclusions.
M
There are so many fascinating dimensions to this I think and to the work you are doing. In particular, in how you describe the mental impact of city living not necessarily being any more negative than the positive effects of nature – or rural living? Which is interesting when I think about some of the conversations I’ve had with earth scientists around these same subjects, but looking at these vast expanses of time, and we might say that for perhaps almost 250,000 years we didn’t have cities as we know them and obviously the trajectory of the global population has exploded in the past couple of thousand years, so by default we are quite an adaptive species but we, you would imagine, in northwestern Europe or this corner of the world in landscapes that oscillate between temperate forest and treeless wetland, then to big expanses of nothingness or controlled vegetation for the purposes of agriculture – keeping in mind the influence of shifiting baselines, you might speculate we are now set off on this pretty wild climate trajectory that we haven’t seen evidence of humans having lived in those beckoning conditions before. So when I start to think about the direction we might be heading in as relates to climate, population still growing, minimal green space available – maybe the more and more quickly that happens, the more information we lose about the environment, how healthy ecosystems should look intergenerationally… how do we really start to positively impact those things, and our mental condition, now?
S
My hope is that somehow, we can find out what the active ingredients are. So I’d love to be able to say, like… what is the necessary element? Is it really the terpenes in the forest, is it the colour green, and I know it won’t break down as easily – there will be some interaction between all of these factors, so I’m not thinking that one alone will be sufficient, but I really think we need to break it down to understand the mechanism. Recently we have done one study in the UK Biobank data, which is a huge data set, where we tried to throw in as many environmental variables as we could. And there we found that of relevant brain structures such as the hippocampus, which in a sense is really like the plasticity region, it is mainly influenced by air pollutants but, by the same degree, green-ness, green spaces around us. The way that we analyse data is a technique with which we can deal with these multipolarities. Sometimes we have a problem in that if you look at these associations and things are highly intertwined, that you can’t tear them apart, but with neuron machine learning algorithms you somehow can, and we can see that they are somehow on the same level, so it doesn’t suffice to explain hippocampus variability when just looking air pollutants, but green has some additional values to explain which I find really relevant. I’m trying to separate modalities, so that we know what is visual input, what is auditory input, what is smell, and what might be the driving modality. And investigating what the effects then of climate change will be is so difficult, because at least in our field changes are so minor that we can’t associate change on that scale – there is just not enough happening yet – but we do feel a difference already, right? It’s hard to collect. And there are so many anxieties in people, I mean, clearly we are all anxious about this, but I don’t think that’s the anywhere near the extent of the effect this will have on us in the future if we are living in those environments. I think the best approach that we can currently take is trying to define what these active ingredients are right now that we can pinpoint are contributing to mental and brain health, and once we know this do our best to conserve these.
M
We have these ideas about and associations around ‘green’ and ‘blue’ – predominating as representations of what we believe to be, and what we seem to be programmed to believe, healthy and positive, but there are multiple examples of whereby that absolutely isn’t the case, for example the history of river restoration projects, or when we consider the extent to which we set our defaults by what we learn from our parents and grandparents as a child – this only takes us back so far, and categories and language shifts and changes… but if I think about what you’re describing about the hippocampus there, these must actually be really hardwired, deeply embedded trends that a green environment equals a healthy ecosystem, seems to be a dominant part of our mental makeup.
S
Yes, but from our perspective it’s just really hard to prove those evolutionary ideas, right? We had one study where we used certain implicit tasks – so, you can ask people to respond to things only superfluously, so you basically instruct them for example to look at something else than the content of a picture and they respond to this, and then you look at whether it has an influence, or a connection to the picture contents, and we find people are a lot faster in approaching and somehow pulling things toward themselves that contain nature and pushing things away that are urban, which all sort of feeds into the story of how we are ‘meant’ for this, but scientifically it’s almost not possible to demonstrate any of these evolutionary theories because you can find instances of behaviour that point to it, but you can’t turn back time. Some of us are thinking about running studies with a very small influence, so that at least you can say that any cultural adaptation hasn’t yet happened – if you have a two-month old for example they will not really know what green space means to us or urban areas mean to us… it’s just hard to prove.
Similarly there is the Savannah hypothesis – I don’t know whether you have heard of this but there is some data suggesting that wherever people come from, they seem to identify with certain types of tree that grow in the Savannah, and for example if you show people pictures of different landscapes, individuals seem to prefer those that look closer to the Savannah landscape. There is some data recently that calls this into question and we really aim to do a larger study on this, because I would really only trust it if I collected the data, but this is super interesting because it would demonstrate some type of transgenerational precoding of where we actually come from. This hypothesis is very old, and people tested this excessively in the 70s and 80s and then stopped completely, but now people are taking it up again.
M
It’s fascinating hearing you describe the ways in which you use images, particularly for me in working with digital media, and at the moment I’m working on building a CG environment that is a kind of reconstruction of Doggerland based on learnings and material generated through research visits I have undertaken in the Netherlands. I’m interested in working into virtual reality as a format in terms of the way we absorb our surroundings – I mean, we are always talking about two different realities essentially, virtual and ‘natural’ but it seems that the way you are using it seems to blur a line – intentionally?
S
In the beginning, when I started this type of research, I thought this was great. I mean we could keep the weather constant and then show a forest and be sure we have the same environment all of the time throughout a study but it doesn’t quite work that way. I mean computer models of trees usually don’t work. Now for example with Unreal Engine this is getting better but obviously nature is obviously going to be hard to represent realistically. We have tried using 360-degree videos, which works okay-ish… we now have platform where we ask people to generate a landscape and design it as they like it, telling them in advance that it’s not meant to be ultra-realistic, but we want to somehow show us what your perfect surrounding would look like. So we ask them to build this landscape then show us a 2D picture basically of this view they would want to see. People vary in skill and vary in motivation, so these things make the pictures less comparable. So we use newer artificial intelligence systems too so people can simply interact and say ‘I would like to see more green’ for example, which makes it slightly easier. So it’s much more that we’re using virtual reality as a tool for people to interact with, and less like trying to place them in an immersive environment. I’m actually increasingly turned away by the idea of showing green spaces in virtual reality because I’m not sure it really works.
M
There is an entirely different spatial basis which is inescapable between these two realities. The idea is that the gap narrows and narrows but I’m sure there’s a very long way to go if that is even possible.
S
I do think with nature there is also an uncanny valley effect, and just because we’re so tuned into the ‘real thing’, it’s so hard to really hit it, and this doesn’t even just apply to humans it also applies to natural environments and the things inside of them.
M
My interest really begins with local history and generational family connections to farming along the Yorkshire coastline, and it seems apparent that there are high rates of neurological diseases and cancer in this particular community, maybe sometimes as a result of chemical spraying practices, I’m not sure. And then with this in mind thinking about the agricultural revolution and how that completely changed our perceptions of the natural world through the ways in which we negotiate and control those spaces to our benefit, from spaces that were likely very densely wooded, with much, much smaller human populations to clearings, enclosures and pasture, and these ‘unwilded’, engineered landscapes have now actually come to define a type of unspoilt countryside culture… I really don’t know whether there are any correlations to be found in any of this but there is something within all of this that keeps me interested. Yesterday I was reading about the scourge of microplastics being found across farmland in the UK, and the associations between microplastics and Parkinson’s for example… these are all things that I think disrupt our sense of the connections between appearance and ecological reality.
S
Yeah, I mean I honestly think it’s very hard to believe all of these stories that focus on one single thing… once we feel like we have understood why all of this happens we realise it’s actually the combination of ten thousand issues – everything is always more complicated than it seems. But what is really interesting these days in science is that they give people – quite frequently they use these in toxicology - silicone wristbands, that can collect all the chemicals that people come into touch with and that can quantify on an individual level their exposure to those chemicals, at least at present. I think that’s a good way forward, not to look at one chemical only but having a broad picture of those things that are around us and to what level they are impacting us.
I’m currently most interested in sky, because there is something here that geographers seem to have forgotten about - I mean we look at green spaces and blue spaces but it seems we are mostly thinking about the ground, and that to me makes a huge subjective difference… we just know that daylight exposure is really important and makes a huge difference to us, so I really do think there is something to be answered in how much sky we can see. Someone from the meteorology section of Max Planck once told me years ago about cloud research he was working on and he told me something that really impressed me – he kept saying how in former times when we maybe didn’t travel that much, or in the same way, we were really familiar with our environments, and nothing could change significantly without us noticing, but the thing that was really changing a lot would have been the sky, and the weather. I don’t know how to test this but somehow we can visualise how differently we might be seeing our world today compared to how people have done so in the past.
M
That makes me think a bit about time and the way we agree upon measuring time actually being something fairly recent, and how predictions around the elements and how best to mediate them, to make forecasts, to be prepared, back then looking at the sky is crucial in understanding these things. I was thinking the other day about how we treat things like camping and outdoor excursions now as some kind of adventure – there’s something slightly scary about being outdoors, especially at night, but for the vast majority of our existence we probably would have been quite familiar with that.
S
Yes and this is something really scary actually – we did a walking study in Grunevald – it’s really a city forest, and we asked people just to walk on the tarmac road – they didn’t have to navigate at all, just walk thirty minutes straight. And we even had a cab waiting for them. And still, people were scared about this prospect of not being able to make their way out of the forest – in the middle of Berlin! People were behaving weirdly around this basic nature exposure, something that we might consider nature, but not unkept or wild in any way – it’s basically a park. So this worries me a little bit to be honest.
