植物氣味對情緒及大腦功能連結之影響

Abstract

植物氣味與生心理效益密切相關，嗅覺比起其他感官更能喚起強烈的情緒反應，然而真實植物氣味如何影響大腦功能連結的研究仍相對不足，故本研究旨在探討不同植物氣味對情緒及大腦功能連結的差異。本研究利用功能性磁振造影(fMRI)結合嗅覺刺激設備(ETT Olfactometer)，以迷迭香、百里香、檸檬馬鞭草等三種真實植物作為氣味刺激來源，控制氣味與呼吸同步；主觀情緒採用快樂、幸福、厭惡、驚嚇、放鬆、寧靜、活力、振奮等八個形容詞作為情緒問項，以四點尺度量表進行量測。研究結果顯示，不同植物氣味對快樂、幸福、厭惡、活力與振奮等情緒具顯著影響。其中，迷迭香與檸檬馬鞭草氣味能有效促進正向情緒反應，迷迭香更呈現強化與正向情緒相關腦區功能連結、同時抑制負向情緒相關腦區互動的特性；檸檬馬鞭草則較具放鬆感及強化情緒調節相關腦區的連結；百里香在主觀量測中引發較高的厭惡感，並展現與活力感負相關之大腦功能連結變化，推測情緒反應可能受到個體偏好與氣味聯想的影響。本研究結果除了揭示植物氣味對大腦生理機制影響，亦提供未來環境植栽設計之參考，期望透過考量不同植物氣味帶給的人的感受以增進環境帶給人的身心效益，為景觀設計與心理健康提供實證依據。

Plant scents are closely linked to psychological and physical well-being, and olfaction is known to evoke stronger emotional responses than other sensory modalities. However, research on how real plant odors affect brain functional connectivity remains limited. This study aimed to examine emotional and neural responses to different plant scents. Using functional magnetic resonance imaging (fMRI) combined with an ETT olfactometer, authentic odors of rosemary, thyme, and lemon verbena were delivered in sync with participants’ breathing. Subjective emotions were assessed using a four-point scale based on eight descriptors: happiness, well-being, disgusted, unpleasantly surprised, relaxed, serene, energetic, and invigorated. Results showed that different plant odors significantly influenced emotions such as happiness, pleasure, disgust, energy, and invigoration. Rosemary and lemon verbena enhanced positive emotions; rosemary increased connectivity in regions related to positive affect and reduced connectivity in areas linked to negative emotions, while lemon verbena promoted relaxation and strengthened emotion regulation networks. In contrast, thyme elicited higher disgust ratings and showed connectivity patterns negatively associated with energy, suggesting that emotional responses may be influenced by individual scent preferences and associative memory. This study provides novel evidence of how plant scents modulate emotional and neural responses and offers practical insights for environmental planting design. By considering the affective impact of plant odors, landscapes can be designed to enhance mental well-being, supporting applications in green space planning and mental health promotion.