For most of the developed world, more and more of our time is spent indoors than ever before, despite the fact that natural environments have been shown to improve quality of life and general health. Natural environments are also known to interact positively with cognitive function, although our understanding of this relationship is still imperfect. By comparing and contrasting 13 studies, a team of researchers has hoped to shed light on this complex interaction in research published in Frontiers in Psychology.

One of the ways by which nature may improve cognitive function, i.e. the acquisition and goal-oriented use of knowledge, is by improving memory formation and recall—specifically that of short-term, or working memory—and goal-oriented or directed attention—the kind that requires focused effort.

The studies selected for review made use of the Backwards Digit Span (BDS) task, which requires participants to inverse a series of numbers and repeat them back to the interviewer. For example, “3-5-2-4-8-7-1” is returned as “1-7-8-4-2-5-3.” The test is cognitively taxing, as subjects must store the initial series in working memory while performing the inversion operation.

The results of the study help clarify some of the ways natural environments benefit the brain and mind. Firstly, all studies demonstrated significantly improved cognition in nature as compared to urban environments, as determined by the BDS test. Furthermore, by examining how first and secondary testing differed in environments, it was shown that urban environments may actually affect cognitive decline, in much the same way nature affects improved cognition. Finally, the metastudy found that, while natural environments tended to improve affect (mood), this didn’t account for the increase in performance, which means that nature interacts with the brain through various, independent pathways, some emotional, others cognitive.

While modest, these results have far-reaching implications for understanding interactions between the brain and different environments. The authors evoke the theory that natural environments contain “softly fascinating” stimuli that prime the brain for directed attention without bombarding it with distractions as do urban environments. This may help account for the fact that greater “naturalness” (e.g. a large nature preserve vs. a small park) results in greater cognitive improvements.

The benefits of studies like this are two-fold, being both epistemological and psychological: not only are we learning more about how the brain interacts with its environment, but also how to leverage this interaction to lead healthier, more productive, and happier lives.

The study, “Positive Effects of Nature on Cognitive Performance Across Multiple Experiments: Test Order but Not Affect Modulates the Cognitive Effects“, was authored by Cecilia U. D. Stenfors, Stephen C. Van Hedger, Kathryn E. Schertz, Francisco A. C. Meyer, Karen E. L. Smith, Greg J. Norman, Stefan C. Bourrier, James T. Enns, Omid Kardan, John Jonides, and Marc G. Berman.