Effects of Green Walls on Prefrontal Cerebral Hemodynamics in Hospital Workers

Background and objective: Artificial environments have been known to negatively affect neuropsychological activities. Healthcare workers who are under high psychological and physiological stress often spend long hours at a time. Recently, many studies have been conducted to reveal the healing effects of natural environments, but few studies have been conducted on healthcare workers. Therefore, this study aims to investigate the effect of green walls in medical facilities on the hemodynamics of the prefrontal cortex in healthcare workers.Methods: Eleven healthy adults working in a medical institution participated in the experiment, in which they rested for 10 minutes in a room with green walls and in a control room. To compare the physiological and psychological changes between the green wall room and the control room, we used various measurements, such as near-infrared spectroscopy in the prefrontal area (NIRS), heart rate variability (HRV), blood pressure (BP), and pulse rate (PR). Psychological tests were also conducted using the Profile of Mood States (POMS), the State-Trait Anxiety Inventory (STAI), the Perceived Restorativeness Scale (PRS), and the Zucherman Inventory of Personal Reaction Scale (ZIPERS).Results: The oxyhemoglobin concentration in the frontal lobe significantly decreased on both the left and right sides in the green wall room compared to the control room. Green walls significantly activated the parasympathetic nervous system and inhibited the sympathetic nervous system compared to the control room. In addition, psychological reactions increased positive emotions and decreased negative emotions.Conclusion: Green walls in medical facilities could be an effective way to promote physiological relaxation and health by reducing physiological hemodynamics in the prefrontal cortex evoked by psychological stress in healthcare workers. This study implies that green walls can be used as an effective means of stress reduction and relaxation.