The Influence of Foliage Plants on Psychological and Physiological Responses

This research aims to clarify the significance of incorporating visual stimulation, in the form of foliage plants, into office desktop spaces. The experiments were conducted in a thermal environment with a temperature range that was slightly uncomfortable. The indoor thermal environment evaluation index ETF was used to measure the effects that brain stimulation of foliage plants have on comprehensive thermal senses. We focus on visual stimulation with foliage plants, and quantitatively measure shifts in thermal senses that affect the body. Thermal environment conditions were established with air temperature in three stages (25℃, 28℃ and 31℃) and the atmosphere was kept homogeneous with wall surface temperature equal to air temperature. The visual stimulations consisted of seven types of office desk image: benjamin, pothos, oxycardium, baby tears, moss ball, cacti, and no plant. At around 27℃ to 29℃ ETF, improvements in thermal sensation, as measured by thermal sensation statements, were shown to have resulted from visual stimulation benefits. Also, at around 26℃ to 29℃ ETF, improvements in comfort were shown, due to visual stimulation benefits as well, in subjects’ comfortable-sensation statements. This benefit was significant when a foliage plant’s green coverage ratio came between 0.75% and 4.67%, the range which does not create an overwhelming feeling from the foliage plant.