The reason such seemingly trivial mental tasks leave us depleted is that they exploit one of the crucial weak spots of the brain. A city is so overstuffed with stimuli that we need to constantly redirect our attention so that we aren’t distracted by irrelevant things, like a flashing neon sign or the cellphone conversation of a nearby passenger on the bus. This sort of controlled perception — we are telling the mind what to pay attention to — takes energy and effort. The mind is like a powerful supercomputer, but the act of paying attention consumes much of its processing power.
This research has special urgency because, for the first time in history, the majority of people now live in cities. Lehrer reports: “For a species that evolved to live in small, primate tribes on the African savannah, such a migration marks a dramatic shift. Instead of inhabiting wide-open spaces, we’re crowded into concrete jungles, surrounded by taxis, traffic, and millions of strangers. In recent years, it’s become clear that such unnatural surroundings have important implications for our mental and physical health, and can powerfully alter how we think.”
Urban challenges face communities worldwide, with solutions lagging behind. These changes range from land use and cover, urban waste discharge and urban heat island effects to global climate change, hydrosystems, biodiversity and bio-geo-chemical cycles. In all, cities are substantive ecosystems in their own right, full with complex human-environmental interactions and far-reaching impacts.
Natural settings, in contrast, don’t require the same amount of cognitive effort. This idea is known as attention restoration theory, or ART, and it was first developed by Stephen Kaplan, a psychologist at the University of Michigan. While it’s long been known that human attention is a scarce resource, focusing in the morning makes it harder to focus in the afternoon. Kaplan hypothesized that immersion in nature might have a restorative effect
Walks in nature and views of green space capture our involuntary attention, giving our directed attention a needed rest.
As it turns out, everyone appears to benefit from the restorative powers of nature. The human brain has two forms of attention: directed attention, which is what we use most of the time to concentrate on work, studies and tests, and involuntary attention, which is what occurs when we automatically respond to things like running water, crying babies or wild animals.
The problem is that directed attention is a finite resource. Everyone has experienced the fatigue of taking a test or a big project at work. Walks in nature and views of green space capture our involuntary attention, giving our directed attention a needed rest.
A historically minded-skeptic might note that there’s nothing new, or even particularly modern, about such anxieties. Charles Rosenberg, a historian of science at Harvard University, has done some marvelous work documenting our tendency to “pathologize progress.” He has shown that the fast-pace of contemporary life has always been seen as harmful to the fragile human brain. The influential 19th century neurologist George Beard, for instance, blamed the telegraph and the steam engine for an epidemic of what he termed “nervous weakness”.
Imagine a walk around Walden Pond, in Concord. The woods surrounding the pond are filled with pitch pine and hickory trees. Chickadees and red-tailed hawks nest in the branches; squirrels and rabbits skirmish in the berry bushes. Natural settings are full of objects that automatically capture our attention, yet without triggering a negative emotional response — unlike, say, a backfiring car. The mental machinery that directs attention can relax deeply, replenishing itself.
“It’s not an accident that Central Park is in the middle of Manhattan,” says Berman. “They needed to put a park there.”
Photo by David_shankbone
