以眼動模式探討偵測情緒變化的年齡差異

Abstract

社交互動中，臉部表情變化可以協助我們判斷他人的動機與情緒。注視臉孔的特定區域，可以有效地提供辨別他人情緒狀態的資訊，並透過這樣的非語言線索影響彼此的互動。過往研究發現年長者在注視靜態情緒臉孔時，較側重於下半臉的資訊。然而，呈現動態的情緒臉孔可能會引發不同的眼動模式。本研究旨在探討偵測情緒變化及其眼動模式的年齡差異，採用臉孔情緒變化偵測作業，並同時紀錄眼動資料。操弄臉孔情緒價性（快樂、悲傷）與變化方向（情緒出現、情緒消失）兩個因子，以參與者知覺情緒改變的情緒強度變化量得出偵測情緒變化的敏感度。結果顯示，在快樂情緒消失的情境，年長者偵測情緒變化的敏感度高於年輕人，且年長者對下半臉的注視時間短於年輕人。年輕人傾向採取專注於下半臉的眼動模式，而年長者則傾向採用平均地注視上、下半臉的眼動模式。在偵測到快樂情緒消失後，年長者會比年輕人更多地注視靠近眼睛的位置，以尋求更多社交資訊。在社交互動中，快樂情緒的消失隱含了不合宜的行為舉止。根據社會情緒選擇理論，年長者比起年輕人更有動機去維持緊密的社交關係，這樣的動機轉變影響到其採取的眼動策略，特別是在動態且更接近互動情境的作業之中。

In social interactions, facial expressions help people infer motivational and affective states of others. Gazing at specific regions of others’ faces provides critical information to understand their current feelings, intentions, and action tendencies, ensuring successful interactions. Previous studies have found that older adults tend to fixate more on the lower face for static stimuli. However, this eye movement pattern may differ when the face stimuli are dynamic. We used an emotional change detection task with an eye tracker to investigate age-related differences in detecting facial emotional changes and eye movement patterns. We manipulated two factors: emotional valence (happy, sad) and the direction of emotional change (onset, offset). The dependent variable was sensitivity to emotional change, calculated from the differences in emotional intensity that participants perceived as indicating a change in emotion. The results revealed that older adults exhibited higher sensitivity in detecting the offset of happiness compared to younger adults. In happy offset condition, older adults spent less time fixating on the lower face than their younger counterparts. While younger adults used a lower-face-focused eye movement pattern, older adults exhibited a distributed pattern, viewing both the upper and lower face in a balanced manner. Even after detecting the disappearance of happiness, older adults fixated more on the upper vertical location than younger adults for additional social information. This might be because the disappearance of happiness provides social cues to indicate that their behavior may be inappropriate. According to the Socioemotional Selectivity Theory, older adults shift their motivation to focus on maintaining close relationships. This shift leads them to alter their eye gaze strategy, especially when the task closely resembles a social interaction.