事件相關電位揭露人們處理正向及血腥圖片的性別差異

Understanding Gender Differences Revealed by Event-Related Potentials in Processing Positive and Bloody Pictures

本研究探討性別對於情緒刺激反應的差異；我們收集了28位受試者（半數為女性）觀看情緒圖片時的腦電波資料，並請受試者評估包括正向、情色、中性、血腥、和負向五種情緒類別圖片的正負向（valence）程度及激發（arousal）程度。即使受試者對於不同類別的情緒圖片在正負向程度和激發程度在主觀評分上面沒有性別差異，事件相關電位（event-related potentials）對於情緒刺激材料所反應出來的晚期正向慢波（late positive potentials, LPP），揭露出行為資料無法觀察到的電生理差異。女性受試者在觀看正向及血腥圖片時的晚期正向慢波（刺激呈現後的400到1,000毫秒間）顯著高於男性受試者；這樣的性別差異並沒有在觀看情色、中性及負向圖片中顯示差別。女性受試者對於正向及血腥圖片這種特殊情緒刺激的反應，可能和在演化過程中長期扮演照顧者的角色有關連性的影響。

We aimed to investigate how men and women respond to emotional stimuli. Therefore, we engaged 28 participants (14 of whom were female) to view pictures belonging to the following five emotion categories of the Taiwan Affective Picture System (TAPS): positive, erotic, general neutral, bloody, and negative. Electroencephalogram (EEG) data was recorded while participants passively viewed emotional pictures. Participants were asked to judge the valence and arousal levels they experienced for each viewed stimulus. Behaviorally, we did not observe any differences in the ratings of both valence and arousal levels across emotional categories between male and female participants. Event-related potentials (ERP) elicited by erotic, general neutral, and negative pictures were also comparable between the two groups. Gender differences were observed for positive and bloody pictures. In comparison to male, female participants showed a larger positive going ERP component for positive and bloody pictures between 400 and 1,000 ms after stimuli onset. This late positive potential (LPP) has been established with emotion-processing associations. We interpreted these characteristic responses to emotion in women as an adaptation in their role as caregivers due to evolution.