The next morning, I wake up early and sneak out of my tent, camera in hand. We’re camped on a natural platform, 50 feet above the sandy wash below. I leave the trail and scramble up a rusty sandstone fin. I pick my way up, trusting the stickiness of my rubber soles and thinking of not much except the view. By the time I’ve reached the top and trained my zoom lens back on camp, the scientists are up and puttering around. “We’re in the peak part of soft fascination,” Strayer tells me later as we pump spring water just up the trail. “I’d really have to stop and think to tell you what day of the week it is right now.”
It’s Friday, three days into the trip—the magic number, according to both hiker anecdotes and preliminary research. Strayer calls it the “three-day syndrome,” or the optimized cognitive state you reach after spending at least that much time in the backcountry. Lab studies prove that even 30 minutes of nature make a difference in cognitive test scores; Strayer’s hunch is that those benefits accumulate. And that makes backpackers uniquely positioned to reap the rewards. “That doesn’t mean that others can’t benefit, but really big improvements are associated with disconnecting for longer periods of time.”
So does that mean that spending, say, three weeks hiking the John Muir Trail will buy me a superhuman prefrontal cortex? Not quite, Strayer tells me: “You probably have the full dose now. I can take three days or five days or 10 days, but in terms of restorative properties, I’m probably already there.” Notice that “probably”—nobody has measured this hypothesis scientifically yet. But if you’re choosing between a two-week backpacking trip once a year and a bunch of three-day weekends closer to home, neuroscientists bet that shorter and more frequent trips give you the biggest cognitive bang for your buck.
Other researchers suspect that even smaller doses of nature can add up. Marc Berman, a post-doctoral fellow at Toronto’s Rotman Research Institute and coauthor of the Michigan arboretum study, says, “Three days is an intensive kind of restoration. But imagine people going for half-hour walks, three days a week, for a year. That could have a cumulative effect.” Still, if research finds that longer periods cause measurably bigger benefits, he says, “Maybe people need to put resources into being able to do that.”
How much wilderness you need for a “full dose” of brain restoration (and how long that dose lasts) is only one of the topics Strayer and the Atchleys excitedly discuss this morning. They bat ideas about the research design back and forth, debating the best tool for capturing the nature effect. The crew is starting with the foundation: They must demonstrate that time in the wilderness actually does something before they can start explaining that something.
“My dream is not to do these pen-and-paper kinds of tests,” Strayer says. “I think the best thing would be if we could just do blood draws and look at blood proteins that are created by interaction with nature. It’s remarkable how fast these proteins are altered by your experience—you get changes within an hour, maybe faster.” Blood proteins provide a peek into how the body is using certain neurotransmitters, including those related to frontal lobe function. Theoretically, blood protein counts could signal altered levels of the neurotransmitters essential to higher-level thinking.
Translation: This nature stuff isn’t all in your head. There could be real, physical changes that unfold the moment you step onto the trail. In addition to blood proteins, saliva samples provide insight into the body’s hormone levels and stress response, while a portable EEG could help researchers infer how taxed the frontal lobe is at a given time. Berman and a team of researchers from the University of Michigan and the Rotman Research Institute are in the midst of a study comparing fMRI scans from people looking at pictures of nature versus urban environments. (An fMRI—functional MRI, which measures brain function, as opposed to an MRI, which looks at anatomy—examines changes in brain activity in different regions.) The team is also planning more work to compare hormone levels before and after the nature walk.
On our fourth morning, in a camp near Jailhouse Ruin, I put my brain to the test once again. Bundled in my bag, I unfold my second Remote Associates Test. ATHLETES, WEB, RABBIT. The answer comes to me in just a moment: FOOT. And maybe it’s only because I expect to do better this time, or because it’s quieter here than it was in Blondie’s diner, but the entire task seems easier. Answers surface in my mind almost automatically, without the frustration of the first go-round.
I’m not the only one who feels smarter. When Ruth Ann Atchley analyzes each of our before and after Remote Associates Tests, the group tallies an average improvement of 45 percent. Imagine that sort of improvement applied to other aspects of everyday life. What would happen to your bank account if your work performance took a 45-percent jump?