The effect of green space behaviour and per capita area in small urban green spaces on psychophysiological responses

Research has shown that there is a close relationship between small urban green spaces and people's physical and mental health. However, most previous studies focus on the macro-level, and there is a lack of empirical studies using real green spaces as the stimulus. The purpose of this study is to explore the effects of two key factors, namely, green space behaviour (GSB) (walking and sitting) and per capita area (PCA) (high, middle and low), in small urban green spaces on the psychophysiological responses of visitors to these spaces. We recruited 240 participants and randomly assigned them to six bamboo-vegetated green spaces with the following different combinations of PCA and GSB: high-sitting, middle-sitting, low-sitting, high-walking, middle-walking and low-walking. The subjects in all six groups performed the same stress tasks indoors (pre-test), then performed green space restoration tasks outdoors (post-test). We measured the participants' beta/alpha index in multiple brain regions, blood pressure, peripheral capillary oxygen saturation (SpO2) and pulse. In addition, we performed a Stroop assessment of their attention level, used the Profile of Mood States (POMS) and collected data on green space preference. The results showed that people have better psychophysiological responses when GSB is matched with the appropriate PCA in a small urban green space. This study concludes that walking in a high PCA and sitting in a low PCA had the most beneficial effects with regard to reducing stress, improving mood and matching the participants' preferences for urban green spaces. These research results can provide guidance for urban green space planning and design.