S2 Episode 11: Into the Woods… to Heal


The gentle sounds of the surf, or sweet birdsong in the trees, are more than just refreshing — they have actual, proven power to heal the brain. Dr. David Strayer, professor of cognition and neural science at the University of Utah’s Applied Cognition Lab, is exploring how our over-stressed, technologically bombarded, multi-tasking brains are restored when we immerse ourselves in nature.  Plus… meet a man who discovered that listening to the sounds of wilderness calmed his ADHD, and led him to a whole new career path.  

Phil Stieg: Hello, today, I have with me Dr. David Strayer, David is professor of cognitive neurosciences at the University of Utah, and he manages the Applied Cognition Lab at the university. He studies the attention network of the brain and how time in nature restores its function. Referred to as nature-based therapies. David, welcome and thank you for being with us today.

David Strayer: Hey, it’s my pleasure. I’m glad to be here.

Phil Stieg: In getting ready, I was thinking about what got you interested in this in the first place, were you out in nature and all of a sudden you realized that you felt better, or did you notice on the flip side of it that all these stimuli, cell phones, iPads, computers, were driving a little bit nuts? So how did it start in your mind?

David Strayer: You know, a little bit of both. I my area of expertise is the cognitive neuroscience of attention. What I noticed when I would go out into nature for two or three days – my senses would recalibrate. I would think more clearly you would see a kind of lower levels of stress. And I started to think in a qualitatively different way. And so I tried to say, what is it about that experience that’s changing what’s happening in our brains, in our bodies? And that’s really kind of led me on a 10-to-15-year quest to try and understand that.

The average American in the US spends about 10 hours a day in front of a screen of one type or another. It could be a TV or a computer or a cell phone or all the gadgets that are in your car. And if you look at our evolutionary history, it’s just a radical shift. And so we’ve put all this technology in front of us and it does bombard us with alerts and phones ringing and doorbells ringing and every electrical appliance in your house beeping or buzzing. So we have created a world of distractions and interruptions. And when you get out into nature, those go away a lot of times. And so you kind of recalibrate and are restored.

Phil Stieg: Can you describe a little bit about the effects of being in nature on specific things that we as human beings are worried about memory, attention, heart rate, respiratory rate, all those things that affect both our physiologic and cognitive aspects?

David Strayer: The first thing we know is that if you go out for a short walk or maybe a longer hike or even a couple of days out in nature, stress tends to reduce. So if we measure things like salivary cortisol or blood pressure or heart rate or heart rate variability, we see markers of reduced levels of biological stress. We can also measure activity in the brain. And there we can measure oscillatory activity and parietal cortex, or we can look at activity and the anterior cingulate cortex, which is kind of the relay or hub for a lot of cognitive control abilities that under law- underlie executive attention. And we see that there are changes in those neural networks. The reason why we see benefits, is you’ve been out in nature, you’ve kind of let the that that problem-solving planning deliberative prefrontal cortex rest for a little while, and then when you turn your attention back to some activity after being on a walk, you can think about it and see it in a kind of a new light. And you we found in some of our studies boosted up that 50 percent in terms of creativity scores. So there are big effects and the kinds of things that Thoreau and John Muir and the like wrote about because it really transformed their life.

Phil Stieg: Let’s face it, computers and cell phones are the way of our lives for the rest of our lives. Is there, a balance between doing that and how much time I should spend in nature, how much time I should spend in yoga or mindfulness?

David Strayer: Yeah, I mean, technology has kind of shaped who we are from fire to printing presses to computers and phones and cars. It’s not that the technology is inherently good or bad, it’s that we need to be smart consumers of that technology. And if we become a slave to it so that whenever the phone rings, we have to answer it, whatever’s on the screen we have to look at that depletes our mental resource reserves and tends to make us be more stressed out. If nothing else, go out and go on a walk. You actually can kind of restore a lot of the mental abilities that probably were kind of diminished. Even relatively modest amounts of exercise improves not only your physical health, but your mental health. And it turns out that what we’re seeing is, in addition, if you can do that exercise with trees and green space in parks that are around you, you get a bigger boost.

Phil Stieg: Explain to us what nature therapy is and how you try to apply that in mental health.

David Strayer: Basically, one of the thoughts is that this is a relatively free, cheap, and very effective way of reducing stress, taking people out and alleviating some of the PTSD syndrome symptoms that you see from at least some portions of the population having effects in terms of reducing depression for kids. We see a lot of kids on drugs to deal with ADHD and you don’t need those. When the kids are running around in natural environments, they seem the kids are basically perfectly fine in the outdoor environment. It’s when they have to sit still in front of a in a desk and in a classroom that they really have problems focusing their attention like that. So nature therapy basically talks about the benefits of being immersed in that natural environment. One of the things that we have found is that if you’re going to try and, you know, just go out on a walk and you want to get the full benefits, you know, that cell phone you’re carrying with you, you know, put it in your pocket, put it in your purse, put it in your backpack. Don’t be using it continuously while you’re on your walk because you it interferes with the restorative benefits. When we’ve looked at changes in brain activity, you don’t see the benefits if people have using their phone on their walk. But if they put the phone away for a little bit, we see really striking differences and just kind of the patterns of neural activity. So and this is after people have hung up the phone there, just kind of a residual kind of activity in the brain just from all that multitasking.

Phil Stieg: You wrote about an example where you had people walk through an arboretum, one with a phone and one without and the differences in what those individuals observed. Can you talk about that a little bit?

David Strayer: We have an arboretum close by at the university. And so we would have people go up there and we would record brain activity both before and after they’d gone on a walk through the arboretum. We also looked to see what they actually remembered and notice from their walk. And people who were on the phone, you know, could only remember about half of what the people who had not been on the phone noticed, something called inattentional blindness. You’re multitasking, so some of the time you’re paying attention to the conversation and not paying attention to what you’re looking. Multitasking. We know it places heavy demands on the prefrontal cortex. That’s the decision making problem-solving, creative portions of the brain. And so if you’re multitasking, you’re not letting that part of the brain rest as you would if you were just walking through the park or the arboretum without all that technology strapped to your head.

Phil Stieg: What I find interesting is one of the more current therapies for post-traumatic stress disorder is confronting the individual with the episode that created their stress. And you’re actually proposing quite the opposite, going out and just being peaceful and enjoying nature. And you’re finding that to be beneficial in PTSD?

David Strayer: We are I will tell you that I take some of the classes that I teach down to the desert for four days. And some of the students who show the most remarkable changes are some of the students who had just come back from a tour in Afghanistan or Iraq. And they are changed radically with that exposure to nature and interacting with other people face to face. I know that the Sierra Club now has a program where they will take vets who are suffering from PTSD on river rafting trips to try and bring them a little bit out of the shell and kind of recalibrate and create a sense of camaraderie with the people who are in the raft with them.

Phil Stieg: David, one of the things I’m curious about is when we are in nature, which sense is it that is which is that the derives the most benefit is that the visual sensation, the auditory sensation, the smell, just the context of being in a peaceful environment. Can you describe them?

David Strayer: First off, it’s not one. It’s all the senses. When you go out into a natural environment, everything changes. You see things that are different. I mean, the idea of soft fascination is you can watch an ocean and the waves coming in or a river flowing by or trees being blown in the wind. You see that kind of soft capture of your attention. It’s the smells. It’s the sounds. We know that in humans, what’s tends to kind of capture our attention the most is vision. We have something called visual dominance, and a huge portion of our cortex is devoted towards processing visual information. So that’s probably that where it starts is with that soft fascination and the visual domain. But to get the full bang for the buck, if you will, it’s going to be vision. It’s going to be the sounds. It’s going to be the smells. I took some people out on a trip once and after three days that go, wow, I’m hearing all kinds of birds. And it’s like, you mean there are more birds here? And it’s like, no, I’m just I’m listening differently. I’m recalibrated. My senses have recalibrated to a natural setting.

Phil Stieg: So I have a twofold question. It goes both ways. Is there a technology withdrawal that a person experiences when they go into nature? And how long does that withdrawal take to overcome? And then when they go back to their urban lifestyle, how quickly do they snap back in and the benefit of nature is all of a sudden lost?

David Strayer: So we’re still studying a little bit about that kind of dose response. But from the studies that we have done, it seems like a clicks and in terms of the benefits start accumulating fairly quickly. And part of that we know is because we see benefits even just walking in an arboretum or park. So you start to see the benefits fairly soon. So there’s something we refer to as the three-day syndrome that seems as if the biggest benefit you’re going to get are within that three day window and they keep growing and thereafter you’re still getting benefits, but maybe not quite as much those. That’s an idea that, as far as I know, came from Edward Abbey and some of his hiking around in the desert. He and his buddies talked about the three-day syndrome. How long it lasts, depends a little bit on the user. So if you get on a vacation and you’re out hiking for two or three days and then you get back and you see that there are a thousand emails in your inbox and you try and process all those in the next two or three hours, you will deplete yourself pretty quickly. One of the things to learn is that, you know, you get the benefits pretty quickly, but to kind of preserve the benefits, you kind of need to slowly, kind of gradually back into the modern world. Yeah, you have to come back and look at emails and phone messages and all that kind of stuff. But if you try and I’ll do that in one setting, you may basically just totally stress yourself out again. And the other thing is that we tend to think that every one of these messages that comes in, we need to respond to immediately. But if you go on a trip for three or four days and you come back, a lot of those messages that you thought were urgent kind of solve themselves.

Phil Stieg: I like to go on a one-week vacation and just shut it off. And it’s amazing how people have forgotten why they emailed you in the first place.

Interstitial – This Is Your Brain: The Guided Tour

Phil Stieg: David, do you think that the parks and arboretums within the city play a positive role in the quality of our lives from a mental health standpoint?

David Strayer: Yeah, there’s no question that our urban environment can be improved by access to trees, parks. There’s all kinds of sociological benefits of living closer to green space and trees. We see lower levels of crime. We see higher improvement scores for kids. And when they have access to natural environments. It’s just one of these ideas that you could actually try and be smart about how you create your environments. Here’s an example. You might think, well, a playground for an elementary school, well, you could pave it over and then it’d be just all nice. You could put lines on it and kids wouldn’t get dirty. It turns out that in doing so, you kind of really change the dynamics of how kids play. You increase bullying with playgrounds, and you decrease the overall level of kind of creative thought play. So you can do relatively simple things like “rewilding” the playgrounds and kind of creating green spaces in the cities. So it’s just kind of a no brainer. You see the most some of the most valuable property that is along beaches and views of mountains and things like that where you can see nature.

One of the things that I find really interesting is people recover more quickly following some kind of surgical event in the hospital. If they have a window that looks out onto some kind of natural scape, a room without a view, they end up actually staying longer. There’s something and this is some of the work that Roger Alrick did years ago that shows that that even the ability to be able to look at a window has restorative benefits, not as much as going out and walking around and getting that full, you know, sensation of the smells and the and everything else. But even a little bit of that tends to actually have health benefits.

Phil Stieg: Just as a physician, I’m going to tease you and say that when I have patients that have their room overlooking the East River, they don’t want to leave. They enjoy the view too much. (laugh)
What do I say to my friends that I invite out to my country house, and they get there, they’re, you know, consummate New York urbanites, they get out there and they go, “I’ve got to get back to the city. It’s too quiet here!” What do we do for them?

David Strayer: They’re probably accurately describing their initial experience, you need to somehow be in that environment for a while and appreciate the quiet. That bombarding of the senses, the sounds of the city, the smells of the city, the sights and everything like that, they just kind of overwhelm our all of our senses. When you go out and you spend a couple of days, if you can, in natural environments, you start to notice the subtle things that kind of really are kind of some of the really more important things. So what I would say to your friends when they go out is just wait a while and see what you notice, because sometimes you can become really more introspective and really think more clearly if you’re kind of disconnected for a little bit from all that technology.

Phil Stieg: Hope not, I’d rather enjoy the real thing. I was wondering, do you feel a little bit like the oncologist who was preaching against cigarette smoking years ago? Now, people just it’s seems to be such common sense that calming down, taking a deep breath, smelling the roses, looking at the ocean, the mountains or a canyon or being in the middle of a desert is just good for you. And do you find resistance to that kind of talk when you go out and about?

David Strayer: For the most part, no, I do sometimes wonder that if you could magically bring up John or John Muir or Henry Thoreau and I told them what I was doing, they’d say “well, of course, it’s obvious that these effects are happening.” We are intricately connected to our environment, and we need to if being involved in natural spaces is healthy for us, we need to try and protect those spaces. The more evidence we have to show that our bodies are really benefited by that kind of exposure, the more likely we can actually kind of craft our public policy to try and protect some of those spaces so that they’re not just bulldozed over for some new housing development.

Phil Stieg: Dr. David Strayer, cognitive neuroscientist, thank you so much for being with me and talking about the benefits of nature-based therapies and the restorative effect that it has on our brain and our body. It was really marvelous talking with you. Thank you.

David Strayer: Thank you.