Thoreau would have liked this study: interacting with nature (at least when compared to a hectic urban landscape) dramatically improves improve cognitive function. In particular, being in natural settings restores our ability to exercise directed attention and working memory, which are crucial mental talents. The basic idea is that nature, unlike a city, is filled with inherently interesting stimuli (like a sunset, or an unusual bird) that trigger our involuntary attention, but in a modest fashion. Because you can’t help but stop and notice the reddish orange twilight sky – paying attention to the sunset doesn’t take any extra work or cognitive control – our attentional circuits are able to refresh themselves. A walk in the woods is like a vacation for the prefrontal cortex.
Strolling in a city, however, forces the brain to constantly remain vigilant, as we avoid obstacles (moving cars), ignore irrelevant stimuli (that puppy in the window) and try not to get lost. The end result is that city walks are less restorative (at least for the prefrontal cortex) than strolls amid the serenity of nature. Here’s the abstract of a new paper in Psychological Science [not online], by Marc Berman, John Jonides and Stephan Kaplan:
Attention Restoration Theory (ART) provides an analysis of the kinds of environments that lead to improvements in directed-attention abilities. Nature, which is filled with intriguing stimuli, modestly grabs attention in a bottom-up fashion, allowing top-down directed-attention abilities a chance to replenish. Unlike natural environments, urban environments are filled with stimulation that captures attention dramatically and additionally requires directed attention (e.g., to avoid being hit by a car), making them less restorative.We present two experiments that show that walking in nature or viewing pictures of nature can improve directed-attention abilities as measured with a backwards digit-span task and the Attention Network Task, thus validating Attention Restoration Theory.
I think you could also make a plausible case that being in nature induces a state of relaxation that is also conducive to insights, which I discuss in this New Yorker article.
The paper, “The Cognitive Benefits of Interacting with Nature,” will be published in a forthcoming edition of Psychological Science. For more, see here.