INFLUENCE OF COLOUR AND ELEMENT IN VIRTUAL NATURE: AN EEG INVESTIGATION

Nature exposure improves cognition, but the distinct roles of colour (green/blue) and element (trees/water) are unclear. Virtual reality (VR) allows controlled dissection of these components. This pilot study used EEG to examine how colour and element in nature environment independently and interactively affect working memory (WM) restoration, with VR providing controlled presentation conditions.
In a within-subjects design, 11 participants experienced six 10-minute VR conditions that manipulated colour (Green/Blue) and element (Trees/Ocean/Pure Colour). Outcomes included the Perceived Restorativeness Scale (PRS), two-back task performance and EEG oscillatory power during VR viewing and task.
Exposure to any VR conditions improved WM performance, as indicated by reduced reaction time and increased efficiency. However, subjective restoration was higher for congruent environments (Green Trees and Blue Ocean) than pure-colour scenes (p < .01). Critically, correlation analyses revealed that in the Green Tree condition, higher PRS was linked to poorer post-exposure efficiency and lower frontal alpha during viewing, suggesting active engagement. Conversely, in the Blue Colour condition, higher PRS was associated with cognitive enhancement, as reflected by greater cognitive efficiency gain and increased central alpha during the WM task.
Our findings demonstrate that while immersive virtual nature promotes a generalised restorative state, the link between subjective restoration and objective benefit is pathway-specific. Green spaces may contribute to active engagement that does not directly aid post-task efficiency, whereas blue hues might facilitate a restoration state and improve cognitive performance. This study provides novel evidence that colour and element must be considered independently in neuro-ecological research and design.