By Michiko Kimura Bruno M.D.
We have all experienced it: stress at work. You are staring at your computer, deadlines mounting, stuck on a project. Taking a walk seems like a waste of time, but you decide to go outside anyway. Maybe there is a small park near your office or home. You breathe in the air, look at the sky and clouds, and notice some greenery; trees, grass, perhaps a few flowers. You hear a bird in the distance and feel the wind against your face.
And suddenly, you feel lighter. Your mood lifts. A random idea connects. You remember a coworker from a previous project whom you can ask for help.
Or, even better, you go for a hike on the weekend. The crisp air, the smell of trees, the chirping of birds, the sound of a stream all feel refreshing. Your worries begin to recede.
And the restorative effect lasts even after you come home and turn the computer back on. Sure, your legs are sore and your muscles a little tired, but mentally, you feel refreshed, ready to face the task that seemed so daunting before.
The Emerging Field of Environmental Neuroscience
Marc G. Berman, author of Nature and the Mind, studied this exact effect of nature on our brain in a scientific fashion.
In a now-classic experiment, participants first completed a cognitive task called the backward digit span, which requires them to listen to a series of numbers and repeat them in reverse order. Then, they took a walk outside for about an hour. One group walked in the Arboretum, in a trail following a river through the evergreeens, and the other, in the busy part of the town, navigating intersections along the commercial storefronts. When they returned, they repeated the same test. The participants who walked in nature significantly improved their scores, but those who did the urban walk did not.
Later, the researchers switched the routes, so the same people served as their own controls and the result was the same: nature walk improved attention and memory, but urban walk did not. The walking was similar. The people were the same. What changed was the environment.
The researchers suggested that nature captures our attention gently, without demanding it. Urban environments, in contrast, are filled with stimulation that demands our attention, such as traffic, signs, people, and potential hazards. Nature, they suggested, gives our directed attention a chance to recover.
Berman is now considered to be one of the leaders of an emerging field, environmental neuroscience, which studies how features of our environment influence the brain, including our attention, cognition, mood and stress. In retrospect, this seems obvious. Our brain is the interface between our inner world and the world outside us. Why wouldn’t the environment in which it operates matter?
Environmental Neuroscience Taps Traditions Like Shinrin-Yoku (Forest Medicine)
The idea that nature can help our health is not new. Research from another tradition suggests that nature’s effects may extend beyond cognition into the body itself.
In Japan, interest in the health effects of shinrin-yoku, or “forest bathing,” has grown, alongside an emerging discipline known as “forest medicine.” Shinrin means “forest” in Japanese, and yoku means “bath.” It is specifically noted that Shinrin-yoku is not exercise, or hiking. Rather, it is the act of being in nature, bathing in the forest atmosphere and connecting with it through our multisensory system of sight, hearing, taste, smell and touch.
Studies have associated forest exposure with lower cortisol levels, changes in autonomic measures, improvements in mood, and changes in measures of immune function.
One intriguing hypothesis involves phytoncides, volatile organic compounds released by trees. Laboratory and small human studies suggest that these compounds may contribute to some of the physiological effects associated with forest exposure, including changes in natural killer cell activity. But they are unlikely to explain the whole story.
Why Nature Helps our Brain
Recent studies using tools such as functional MRI and EEG are beginning to show that natural and urban environments engage the brain differently, including networks involved in attention, stress, emotion, and self-referential thought.
According to Attention restoration theory (ART), “attention” is a finite resource, that can be depleted by constant stimulation.
Modern life constantly demands directed attention: ignore the notification, answer the email, switch between windows, remember the deadline at work—while also scheduling the dentist appointment, arranging the car safety check, and figuring out the family vacation.
Our attention rarely gets to be off duty. Nature captures attention differently. A cloud moving, leaves rustling, water flowing, birds calling—these attract us without demanding that we concentrate on them.
This gentle capture of attention has been described as “soft fascination”: interesting enough to engage us, but not so demanding that it taxes our directed attention. This may give our attentional resources an opportunity to recover.
In short, looking at trees may restore attention when scrolling through something entertaining on your phone does not.
One of the intriguing ideas that researchers have begun to ask is whether some of nature’s restorative qualities lie in visual geometry. Built environments are often dominated by straight lines, sharp edges, and regular geometry. Natural environments tend to contain more curves, irregularity, and complex patterns. Nature also tends to contain repeating patterns at different scales: the branching of a tree, the veins of a leaf, the irregular edge of a coastline, what may be called as “fractal.” patterns.
Studies suggest that people generally prefer natural images, and viewing them can improve mood. But preference alone does not appear to explain nature’s cognitive benefits. In Berman’s studies, participants did not necessarily have to enjoy their nature walk more to show improvement in cognitive performance.
In other words, nature’s cognitive benefits may involve more than simply enjoying what we see. Something about how the brain processes natural environments may itself matter.
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So the next time you are staring at your computer, stuck on a problem, going for a walk may not be procrastination. It may be exactly what your brain needs.
Neuroscience has historically spent far more time studying what happens inside the brain. Environmental neuroscience is beginning to change that. If our surroundings influence attention, stress, mood, and cognition, then the environments we build are not simply backgrounds. They are part of the biological conditions in which our brains function.
Perhaps brain health begins not only with what we do to our brains, but with the worlds we ask our brains to live in.
References
Berman, M. G. (2025). Nature and the mind: The science of how nature improves cognitive, physical, and social well-being. Simon Element.
Berman MG, Jonides J, Kaplan S. The cognitive benefits of interacting with nature. Psychol Sci. 2008 Dec;19(12):1207-12. doi: 10.1111/j.1467-9280.2008.02225.x. PMID: 19121124.
Li Q. Effects of forest environment (Shinrin-yoku/Forest bathing) on health promotion and disease prevention -the Establishment of “Forest Medicine”. Environ Health Prev Med. 2022;27:43. doi: 10.1265/ehpm.22-00160. PMID: 36328581; PMCID: PMC9665958.
Michiko Kimura Bruno, M.D., is a Movement Disorder Neurologist, practicing in Honolulu.
Originally published @ Psychology Today
