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

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.