Natural Element: Think Outside the Block

You've been working intently for three hours straight and your brain is Jell-O. You decide that a little fresh air and a stretch of the legs will do you good and you grab your coat. But where you choose to walk it off matters; a stroll around the block may not do.

Researchers at the University of Michigan have found that a 45-minute walk in a park enhances cognitive performance, but walking around downtown does not. Similarly, a stint merely looking at pictures of nature helps attention and working memory, unlike staring at urban photos.

Why does a bit of greenery help us think better? Stephen Kaplan, an author of the study, argues that different environments recruit different kinds of attention. Urban environments require intense concentration in order to process the overload of arresting stimuli; it's hard work to navigate traffic, tune out cell phone conversations, and ignore advertisements. Nature, on the other hand, provides fascinating, but not alarming, stimuli, like a rosy sunset or the rustle of leaves. They catch our attention in a modest way, giving our mental muscles a chance to refresh.

The benefits of a natural environment go far beyond cognitive performance: Exposure to nature has been correlated with decreased stress, diminished anger and anxiety, increased job satisfaction, and faster recovery times for postoperative patients. Sunshine and breezes really are the key to renewable energy.—Courtney Hutchison

Nurturing Nature

Seventy percent of Americans now live in an urban environment. Below are major cities ranked by the size of their open/green space as a percentage of total city area.

25.7% New York

19.8% San Francisco

19.1% Washington, DC

15.7% Boston

12.4% Philadelphia

9.9% Los Angeles

8% Chicago