Restorative effects of olfactory valence and visual environments on post-stress affective and physiological responses

Multisensory stimulation has emerged as a promising approach to modulating affective and physiological responses. Among sensory modalities, olfaction and vision have received increasing attention due to their unique mechanisms. However, empirical research on how olfactory and visual stimuli interact to influence affective and physiological recovery following stress induction remains limited. The present study employed a mixed experimental design, with visual environment as the within-subjects factor and odor valence as the between-subjects factor. A total of 90 participants were recruited. Participants first completed the Mannheim Multicomponent Stress Test (MMST), followed by exposure to different combinations of visual and olfactory stimuli. State anxiety and affective responses were assessed using validated self-report measures, including the Positive and Negative Affect Schedule (PANAS) and the State-Trait Anxiety Inventory (STAI). Physiological responses were assessed using indices of autonomic activity, including the root mean square of successive differences (RMSSD), mean heart rate (Mean HR), skin conductance level (SCL), and skin conductance response (SCR). The study aimed to examine how odor valence and visual environment jointly influence affective and physiological responses after stress induction. The results indicated that: (1) both odor valence and visual environment showed significant main effects. Specifically, positive odors and natural environments effectively reduced state anxiety and negative affect while enhancing positive affect. (2) For physiological responses, visual environment primarily influenced heart rate, whereas odor valence significantly affected skin conductance activity; (3) a significant interaction between odor valence and visual environment was observed, with the combination of positive odors and natural environments producing the optimal regulatory effect; and (4) olfactory stimulation showed stronger effects on stress-related responses than visual stimulation. Together, these findings advance our understanding of multisensory interactions in post-stress affective and physiological responses and provide implications for restorative environmental design and psychological intervention.