Vertical greenery buffers against stress : evidence from psychophysiological responses in virtual reality

Abstract

Vertical greenery has been increasingly adopted in high-density cities to create greenspace above-ground. However, little is known about the psychophysiological effects of vertical greenery. This research used virtual reality to examine the stress-buffering effects of vertical greenery. A total of 111 participants were randomly assigned to walk in a street with buildings covered in green plants (plant condition) or green color (color condition), while simultaneously being exposed to heavy traffic noise (stressor). Results show no changes in pre-test to post-test positive affect in the plant condition, while positive affect significantly decreased in the color condition. Furthermore, physiological responses measured by heart rate variability suggested no change in stress level from baseline in the plant condition but increased stress level from baseline in the color condition. This is the first study to reveal the psycho-physiological benefits of vertical greenery across the exteriors of a row of buildings and has important implications for urban design and city planning.