We already knew that exposure to nature had beneficial effects on health. Now we know a little more about the changes it triggers in the brain, thanks to a literature review on the subject conducted by researchers at McGill University and Adolfo Ibñez University in Chile.
The longer and more immersive the time spent in nature, the more significant and lasting the health benefits, but even just a few minutes spent in a natural environment, such as a park, is enough to see positive effects on the body and mind.
“I think there is growing recognition that nature has a calming effect on us and is beneficial in reducing stress and improving emotional regulation,” said Mar Estarellas, co-lead author and postdoctoral researcher in the Department of Psychiatry at McGill University, in an interview.
There was a whole “spectrum” of levels of exposure to nature in the studies, ranging from simply looking at a picture of nature on a computer to complete immersion in a forest.
“Simply looking at images of nature for three minutes already had an impact on these people’s stress levels, attention, mind and body regulation,” Estarellas points out.
She and her team reviewed 108 studies involving brain imaging conducted over the past 20 years, including electroencephalograms (EEGs) and magnetic resonance imaging (MRI).
“What can we learn from all these studies, conducted in different parts of the world, in different laboratories? I think that’s where their interest lies: they reveal many commonalities that everyone can see, which gives them even more weight,” she said.
In analyzing the studies, the researchers observed certain trends and identified what they call a “cascade model”, which illustrates the brain’s response to nature.
First, the brain needs less mental effort to process sensory input than it does in cities or online. As the sensory load decreases, the heart rate slows, breathing deepens, and the regions of the brain involved in threat detection, such as the amygdala, become less active.
“It’s as if your brain and body find it much easier to process sensory stimuli from nature. Your fight-or-flight response slows down, your attention regulates itself. I suppose you then experience a kind of soothing fascination with nature, which softens your attention and allows you to rebuild yourself, in a way. And the brain networks that are correlated with introspection or self-reflection also slow down. So it’s also a complete slowdown, from the senses to higher functions… and all the more complex processes, such as rumination, also slow down,” said Estarellas.
She hopes that her work will encourage conversation around green urban planning and that more doctors will be inclined to recommend that their patients spend time in nature.
“One of the goals I hope to achieve with this study is to highlight the importance of integrating natural environments more into our society and culture, not only in cities, but also in hospitals, schools and around us in the office, for example. I am deeply convinced that this would be very beneficial for all of us, and I hope that it will have a small impact, at least a beginning of an impact,” she concludes.
The study was published in the scientific journal Neuroscience and BioBehavioral Reviews.
The Canadian Press’s health coverage is supported by a partnership with the Canadian Medical Association. The Canadian Press is solely responsible for this journalistic content.
–This report by La Presse Canadienne was translated by CityNews
