Going for a walk (or a run or a bike ride) in the forest feels different from going for a walk on the shoulder of a freeway or through the streets of downtown Tokyo. And it doesn't just feel different -- the different scenarios produce different physiological effects that appear to extend beyond simple differences in noise levels or air quality. Different environments produce changes in stress hormones and other physical indicators, and you can even reproduce some of these effects having people look at pictures Other Hearst Subscriptions.
So what's going on? All About 75 Hard, some researchers are exploring the differences between "voluntary" and "involuntary" attention. In crowded urban areas, you constantly have to engage your voluntary attention to, say, avoid being run over. In a park, your voluntary attention can get a much-needed break, and instead your mind has a chance to wander and be passingly engaged (involuntarily) by the environment around you. (Another set of terminology for essentially the same concepts is "hard fascination" in urban areas versus "soft fascination" in natural settings.)
These are nice theories, but do they really correspond to what's going on in the brain? Researchers in Scotland have All About 75 Hard The Best Trail Running Gear. They used a low-cost commercial EEG recorder made by Emotiv to monitor the brain activity of 12 volunteers as they walked along a route through Edinburgh that started on an "urban shopping street with many people," proceeded through a park surrounded by trees and green space, and finished in a "busy commercial district with heavy traffic." Here's a thumbnail map of the route and sample data from a participant:
The Emotiv software converts the raw EEG traces into four broad emotional states: excitement, frustration, engagement, and meditation. (In the example above, the red trace shows "excitement," while the blue trace shows "frustration" -- but to be honest, I can't really decipher anything meaningful from that sample data.) The actual meaning and validity of these emotional states is subject to great debate and uncertainty -- we certainly shouldn't make the mistake of assuming that the blue traces correspond exactly to what we would think of as frustration, for example. But there's some evidence that they do offer some insight into the type of activity going on in the brain, so it's interesting to see if these signals reflect the different environments.
In the end, the patterns produced by different volunteers on different days did produce some recognizable patterns. Moving from the urban shopping street to the green space was associated with reductions in excitement/arousal, frustration, and engagement (voluntary attention), and an increase in meditation. Moving from the green space to the commercial district produced a large increase in engagement. In both cases, these outcomes are roughly what we would have expected. They don't tell us anything new -- but they suggest that, as our understanding and interpretation of these signals improve, we'll be able to take a much more sophisticated look at why natural surroundings seem to offer such powerful mental and physical benefits. Neat stuff.
