The beneficial effects of nature and natural environments have been extensively researched and the findings generally support that nature and natural environments can reduce stress and improve cognitive function. To evaluate if self-reported stress levels are reduced, or if cognitive functions are enhanced among adult learners in the presence of a natural environment as compared to an artificial environment, eighty-four adults, predominately between the ages of 19 and 25 (n = 69) were tested using a repeated-measures design in one of four experimental conditions (n = 21). Group 1 was first tested in an artificial environment and one week later in a natural environment, group 2 was first tested in a natural environment and one week later in an artificial environment, group 3 was tested at both time points in an artificial environment, and group 4 at both time points in a natural environment. The artificial environment was one of two rooms located in the same academic support building, and the natural environment was a garden composed of horticultural and other natural elements located in close proximity to an academic building. Four standardized cognitive testing instruments were used to test verbal memory and learning, working memory, spatial fluid intelligence, and executive function. To measure self-reported stress, a modified form of the Perceived Stress Questionnaire was used. No significant findings supported that cognitive function was enhanced in a natural environment. However, in group 1 (A1 -- N2), the effect size indicated a medium relationship existed between the natural environment and reduced stress (d = 0.42), and a trend of lower stress levels was observed in all groups when tested in the natural environment. The findings suggest that a natural environment positively impacts stress in adult learners. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]