Material authenticity drives neurophysiological restoration: Role of plant dyes and natural fibers

While the restorative potential of biophilic design is well-recognized in mitigating urban-induced stress, current research predominantly focuses on macro-scale green spaces, critically overlooking the neurophysiological implications of the immediate micro-scale textile environment. This study addresses the lack of objective health-benefit evidence for sustainable textile materials derived from industrial crops, specifically plant-based dyes, and natural fibers. To decouple the restorative effects of material attributes from visual color hue, a multi-modal experimental design was employed, utilizing Ordinary Least Squares (OLS) regression models based on multi-channel EEG data to quantify the independent predictive effects of material naturalness and dyeing craft on human physiological health. Our analysis reveals a sophisticated functional dissociation in how material attributes relate to the central nervous system. Dyeing craft is primarily associated with neural relaxation, given that chemical dyeing showed a significant negative correction with both the relative α index (β = −0.041, p < 0.05) and the introspection-related (α+θ) index (β = −0.061, p < 0.05) compared to plant-dyed alternatives, serving as a potential physiological stressor. Conversely, material naturalness correlates with physiological arousal, where a higher perception of naturalness was significantly associated with reduced physiological vigilance for the relative β index (β = −0.037, p < 0.05). Furthermore, we identified a “Yellow Paradox” where plant-dyed yellow fabrics were linked to profound relaxation while chemically dyed counterparts corresponded to high arousal, suggesting that material origin can override the intrinsic emotional valence of color hue. Collectively, these findings provide the first neurophysiological evidence that material authenticity is a key factor associated with environmental restoration. This research challenges the visual-centric paradigm and offers a robust scientific basis for integrating nature-derived industrial crop products into evidence-based biophilic design to enhance psychological sustainability in the modern built environment.