Exposure to green space can be associated with stress reduction and increased meditation as indicated by a 2013 Edinburgh study that used portable electroencephalograms (EEGs) to analyze brain wave patterns. Each participant walked through an urban shopping district, green space, and a busy commercial district. The more heavily trafficked areas elicited feelings of frustration, while brain wave readings taken during the walk through green space indicated lower frustration and increased meditation.
Aspinall, Peter, Richard Coyne, Panagiotis Mavros, and Jenny Roe. (2013). The urban brain: Analysing outdoor physical activity with mobile EEG. British Journal of Sports Medicine. https://doi.org/10.1136/bjsports-2012-091877