Impact of sky view factor on multimodal physiological responses: integrating EEG, heart rate, and thermal sensation in urban landscapes

Abstract

Abstract Traditional thermal comfort models often fail to capture the dynamic neurophysiological complexity of outdoor human perception. This study introduces a neurophysiological approach to investigate how Sky View Factor (SVF) modulates human comfort. A controlled indoor-outdoor protocol was implemented, transitioning participants from a neutral baseline to a stressor before exposure to varying SVF gradients. High-precision EEG, HRV, and skin temperature data were synchronously analyzed. Our primary analysis did not reveal a statistically significant main effect of SVF on alpha power (F(2, 38) = 1.89, p  = 0.165, η 2  = 0.090). Heart rate also did not significantly change from baseline to stress (t(40) = 0.40, p  = 0.694). However, a marginal trend was observed for higher alpha power in High SVF compared to Medium SVF environments (Welch’s t(21) = 1.96, p  = 0.065), suggesting a potential pattern that warrants further investigation with larger samples. These findings suggest that while the visual openness associated with high SVF may function as a psychological buffer against thermal stress, this effect is embedded within a composite environmental context where SVF co-varies with microclimatic factors like solar radiation.