The nose cooperates with the eyes: The independent and interactive effects of vision and olfaction on the perceived restorativeness of a Metasequoia walkway

Abstract

In response to worldwide calls for promoting health and well-being, there is growing interest in creating restorative environments. Although restorative environments can be perceived by multiple sensory modalities, visual studies dominated the majority of restorative research, while olfaction is a frequently overlooked yet important sense. Grounded in Attention Restoration Theory (ART) and cross-modal interaction of olfaction and vision, this research seeks to investigate the independent and interactive effects of vision and olfaction on the perceived restorativeness of a Metasequoia walkway in urban green space. The visual stimulus was a 360-degree virtual reality (VR) tour in a 200-meter-long Metasequoia walkway, and the olfactory stimulus was Metasequoia essential oil extracted from the tree leaves. Based on a stress recovery experiment, 120 participants were randomly assigned to one of four groups: control, vision, olfaction, and combination. Psychological evaluations (semantic differential scale [SDS] and perceived restorativeness scale [PRS]) and physiological measurements (systolic blood pressure [SBP], diastolic blood pressure [DBP], heart rate [HR] and blood oxygen level [BOL]) were used as indicators of restorative effects. The findings reveal that a combination of visual and olfactory stimulation can contribute more to restorative effects compared to a single stimulus, in terms of both physiological and psychological indicators. This calls for a greater focus on the effects of vision and olfaction towards more sustainable landscape design and management.