Nature and the brain

Psychologist turned science writer Jill Suttie, from the Greater Good Magazine at the University of California, Berkeley, told Katie Haylor about some of the science around stepping out into nature...

Jill - Exercise is very stress-relieving, but there is an augmentation of doing exercise in nature or in a green space of some kind. And there have been experiments that have shown that when people walk in a green space, a nature setting, or even when they just look at scenes of nature or videos of nature, there's something about that that relaxes the stress response. In the brain it would be the amygdala, it seems to affect the amygdala. Which is part of the sympathetic nervous system, which is our basic fight or flight response system. It seems to soothe that and increase activity in the parasympathetic nervous system, which helps relax us. So that's kind of a broad finding around stress.

其他大的方式似乎是givi影响我们ng us a break from cognitive activity or activity that involves a lot of concentration and attention. So for example, there've been studies that have shown going, you know, when you spend time in nature, afterwards your brain is had a chance to rejuvenate, uh, in a way, and it makes you more able to solve problems, have better recall on memory tasks. So what you're doing, it sounds like a good thing to do because it should help to relieve the stress and also to relieve the cognitive overload that you might have been experiencing by playing with your computer or looking at all these different screens.

In terms of why does nature do that? There's more research on how it does it or showing that it seems to have an impact. But why? They're only theories, really. One of the big ones comes from Roger Ulrich, he calls it biophilia. Well, it's also been coined by other people, but he's looking at possibly our connection to nature, which we've evolved to have. So we have a natural affinity for natural scenes because we needed elements in nature to survive and to feel safe. If you're in a forest, you have some kind of protection from potentially from predators. Or if you are able to see far and wide, you, you have some ability to scan the horizon and see if there's danger on the horizon. And then there's also, of course, food sources and oxygen and all of these things that we get from nature that are very, just basic to our survival. So we have a natural affinity for those spaces and being in them, there's a theory that because of that, when we're in them, it creates positive emotion, which is also stress-relieving.

Katie - You said earlier, even if you just look at a picture of a natural scene, looking at nature makes us feel less stressed, is that right?

Jill - It is right. And I, I think you can pretty much see how that plays out in just the world, you know, how many people are posting like these beautiful nature scenes on their social media and how many people go to the sites where these, you know, the most fantastic nature photographs around the world. And there's a real attraction to that. I think it does help. I mean, it might not be exactly the same as being outside because you get other benefits from being outside and it's a more immersive experience, and you're smelling and you're hearing sounds and other things that you might not get from just looking at a static picture. But they have done experiments where, for example, they've had people look at nature videos. They would take people in a lab and expose them to a very stressful event of some kind - often they used video like movies that were scary or stress inducing! And then afterwards they would have people either look at videos of nature or videos of urban scenes or other non-natural settings. And then they had them hooked up to all of these, uh, instruments to help measure physiological response. And they find that when people look at the nature scenes, they can recover from that stress much more quickly. So it isn't just being outside, although that is really beneficial. And I would argue maybe much more beneficial. You can just by kind of seeing a natural scene feel better.

Katie - Is there evidence that being out in nature can help us to be a bit less brooding or to ruminate less?

Jill - Yes, there definitely is. There is some work out of Stanford. Greg Bratman did some studies on looking at how being out in nature affected people's moods. And what he did is he set up an experiment where you had people walk along the road in Palo Alto, I guess, where Stanford is, or walk through a wooded area. And, you know, they calibrate it so that it's the same amount of physical activity and, you know, same amount of, uh, elevation gain, that kind of thing, to try to, keep the two experiences mostly equivalent except for the nature element. And then he found that there was decreased rumination in the people who walked in the wooded area. And he actually also did a second follow-up experiment where he looked at what was going on in their brains and was able to find that there was this part of the brain that's connected to rumination had decreased activity. But increased activity in that part of the brain is what's connected with rumination.

You can see other experiments too, where looked at things like tree cover or tree canopy cover in a city and found where there are trees there's less crime, even if it isn't any different than a place without tree cover. So there is something soothing about nature that seems to impact our moods and our stress levels and our overwhelm that might have social effects as well.

Katie - So can being in nature change the way you behave towards other people?

Jill - There have been experiments showing that natural elements or being in nature seem to create more kindness towards others, and in various ways. So how have they measured this? Well, there was a series of experiments done, actually at the University of California, Berkeley, where we are at. And our faculty co-founder Dacher Keltner was involved in some of these experiments where they basically, for example, they had people watch nature scenes, and then they had them play these economic games or, or other kinds of scenes, other non-natural scenes. And they had them play these economic games that measure trust, trust levels, or generosity. And they found differences in the people who saw the nature scenes versus the other scene, the non-natural nature scenes. Why is that? It could be tied to all the things that we've already talked about. It could be because of stress-relief.

But there's also been some evidence that looking to nature can inspire feelings of awe, which is something that Dr Keltner studies in particular. For those who aren't familiar with how they define that in psychology, it's like a sense of wonder, coupled with a sense of being part of a small part of a larger universe or kind of a small self feeling. And I think that particular element, the small self, might be tied to how people end up being kinder. They see themselves as less self-important maybe? They also feel good because a sense of wonder, just feels magical. You know, when you see an spectacular sunset or amazing mountain ranges, or just even sometimes seeing the diversity of a forest can inspire this sense of awe and wonder. And that seems to be tied, to being more helpful, kinder.

For example, one of the other experiments they did was, they had students at the university spend a short amount of time looking either at the tall buildings on the campus or at a grove of eucalyptus trees, which were very tall. And then they had this experiment afterwards, where the person who was conducting the experiment, but was a confederate basically. They ended up dropping a bunch of pencils, looking like they had just dropped a bunch of pencils, and they saw who got up and help them pick up the pencils and how many pencils they helped them pick up. And they could measure like how kind or helpful, altruistic these folks were being. And they found that just from that short amount of exposure, looking at the trees, people were more helpful and experienced feelings of awe. So there is some evidence that being in nature or being exposed to natural elements seemed to make people kinder or more altruistic or get along better with others.