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.

The rapid increases in urbanization and time spent in built indoor environments have sparked significant concerns about their impact on human health and well-being. People who spend long hours in enclosed and highly artificial settings, such as hospital workers, are especially vulnerable to environmental stressors. This study examined whether applying biophilic (i.e., human tendency to connect with nature and other lifeforms) spatial design within hospital spaces could provide restorative benefits for nurses working in high-stress environments. Twenty-one nurses participated in this study, staying under two different conditions for 10 min: a control room with plain white walls and a biophilic space where the walls were entirely covered with vegetation. During the sessions, functional near-infrared spectroscopy was used to measure hemodynamic responses in the dorsolateral prefrontal cortex (DLPFC). Additionally, standardized self-report questionnaires were used to analyze the level of perceived restorativeness, affective states, mood, and anxiety. Results showed that exposure to the biophilic space significantly reduced oxyhemoglobin (oxy-Hb) concentrations in the DLPFC, reflecting relief from cognitive–emotional overload and enhanced neural stabilization. Psychological measures further indicated decreases in fatigue, depression, and anxiety, alongside increases in vigor, attentiveness, and perceived restorativeness in biophilic space. These findings demonstrate that even brief exposure to a biophilically designed indoor environment can produce neuropsychologically restorative effects, suggesting biophilic interventions as sustainable, effective strategies for healthier workplaces and urban environments.