The researchers found that participants who had viewed nature scenes had higher activity of the parasympathetic nervous system — the “rest and digest” branch of the autonomic nervous system, which helps balance the activity of the sympathetic, or “fight or flight,” branch — than the other participants. Newer research suggests that the more awe-inspiring the scene, the better.
In a 2015 study,2 people who looked at scenes of awe-inspiring nature (grand mountain ranges and giant waterfalls, for example) had an even greater increase in mood than those who viewed “mundane” nature scenes such as parks and gardens. The awe-inspiring scenes also encouraged a more pro-social value orientation among participants.
These benefits “seems to be related to the visual structure of nature, which seems to be relaxing for our minds. The mechanisms behind this are not yet clear, although my speculation is that nature contains a lot of repetitive structure, which is ‘easy’ on our minds,” said study co-author Yannick Joye, PhD, a researcher at the University of Groningen in the Netherlands. The mood improvement was found to be mediated by the feelings of awe, which can “pull you away from your daily petty concerns, and this could improve your mood — which is actually often determined by those small concerns.”
The sounds of nature appear to have similar benefits, according to a 2013 study3 showing that hearing recorded sounds from nature had similar effects on recovery from a stressful situation as the study involving nature images. As for time in the outdoors, researchers from Nippon Medical School in Japan compared the effects of walking through a forest versus walking through a city. Their results4 show that “forest bathing,” as they call it, not only led to decreased stress hormones, but actually increased the natural killer cells of the immune system and the expression of anti-cancer proteins.