Effects of urban green space on human cognition: A systematic search and scoping review

Abstract

Urban green space is associated with cognitive functions, but the underlying mechanisms remain unclear due to limited research. Given the diverse forms of green space, which lead to distinct health effects, it is essential to differentiate between types of green space. In this review, we propose a novel conceptual framework categorizing three primary effects of green space on cognitive function: functional, spatial, and perceptual. We then conduct a scoping review using the Web of Science, identifying 37 relevant studies. Among them, 20 studies employ modeling to explore potential mechanisms, while 17 studies infer pathways indirectly. Most studies examine reduced air pollution and increased physical activity as mediating factors, with stronger support for air pollution reduction as a protective mediator. However, evidence on physical activities as a mediator remains mixed. Some studies suggest that merely perceiving green space enhances brain activity, and exposure to nature is linked to improved test performance. Other potential pathways, such as heat reduction and social interaction, remain underexplored. We highlight the limitations of current methods in distinguishing various forms of green space and emphasize the need for advanced methods, such as local climate zones and street view imagery, for more precise assessment.