A walk in nature is good for your brain — a new study adds to the evidence

A walk in nature really is good for your mental health, including your ability to focus attention, according to researchers at the University of Utah.

A recent study, published in Scientific Reports, found that a 40-minute walk in nature helped people recover from a demanding mental task, and restored the ability to focus.

Psychologists have theorized that humans have evolved to benefit from the sights, sounds and smells of the natural environment. The idea, known as biophilia, suggests that we have a connection to nature that is beneficial to our physical and mental health. 

Most of us spend more time in urban environments — inside buildings or walking on pavement — instead of a forest floor, and our lack of exposure to natural environments means we could be missing out on the physical and mental health benefits of quiet time in the natural environment. In addition, our immersion in technology, some of which we even wear, is constantly demanding our attention, which can exhaust our capacity to direct our attention to what we're doing. 

Of course, the idea that a walk in the woods is good for you is not new. Conservationist John Muir, who was key in establishing national parks in the U.S., wrote in 1901: "Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves." 

Muir's wisdom has new support from the University of Utah brain scan study. Researchers compared brain activity and mental performance of 92 volunteers that were randomly split into two groups. Individuals in both groups took a 40-minute walk. One group took a nice nature walk, along a trickling creek, through an oak tunnel, around a pond with ducks and a waterfall. The second group strolled among buildings and parking lots. Both groups walked the same distance, over roughly similar terrain so they both got the same amount of physical exercise and no one was allowed to use their electronic devices or talk to anyone along the way.

To measure mental performance, the subjects were given before and after tests while wearing electroencephalograph, or EEG caps, with 32 sensors that record brain activity. The before-test involved two steps, the first to count backwards from 1,000 by sevens. Try it and you will find it gets increasingly difficult as you go on, requiring more and more attention as you fatigue. That was to exhaust their attention reserves in the brain.

Then they were given a standard Attention Network Task (ANT) test, which evaluates the capacity to be alerted to a new stimulus, to orient their attention, and something called executive control, which is roughly the ability to focus on a task. During the tests, the EEG cap recorded activities in areas of the brain such as the cerebral cortex, which is involved in decision-making.

Following the walks, everyone took another ANT test. While there were similarities among the two groups, those who walked the natural path performed significantly better when it came to executive control. This experiment using EEG data provides direct neural evidence that nature has a positive effect on the brain. 

Taking time to simply look at clouds, trees, rivers or vast landscapes involves no decision-making and appears to allow the brain to relax, recover, and function more effectively afterwards. 

The researchers want to continue the study to see how cellphone use while walking in the woods affects mental performance afterwards. So even if you don't have easy access to nature, perhaps just turning off the devices surrounding you for 40 minutes and taking a quiet stroll could provide a little rest and restoration for your brain.