Aroma Olfactory Intervention: Enhancing Stress Recovery via Brain Neural Activity Modulation

Indoor environmental quality significantly affects occupant health, making stress-reduction interventions in built environments important. Aroma, a key sensory element, requires validation for stress relief. This study induced stress in 24 participants using a difficult arithmetic task in a controlled lab. EEG was recorded during exposure to lavender essential oil, a blended essential oil, or no aroma. Analyses focused on EEG microstates and functional connectivity. Stress reduced microstate C frequency, increased A-D transition probability, and weakened functional connectivity. Both aromas reversed these neural abnormalities toward baseline. The blended essential oil significantly enhanced theta-band functional connectivity, indicating a superior stress-relief effect compared with lavender. Integrating specific aromas indoors can thus promote user stress recovery, supporting aroma-based biophilic design for mental health.