情緒可以受到多種因素影響，其中情緒情境是最重要的因素之一，過去的研究曾以面部表情建立情緒情境，結果顯示，參與者對中性面部表情的價性評分，會因情境是負向或正向而有所不同。在此基礎上，我們希望探討當參與者接觸大量負向或正向圖片時，是否會影響其對中性圖片的價性評分。具體而言，我們目的在檢驗不同的情緒情境是否會導致參與者將中性圖片評價得更為負向或更為正向，並想了解實際為近墨者黑還是近墨者白。 不僅情緒情境會影響參與者對刺激的價性評分，性別與個人特質也扮演著重要角色。大量文獻指出，無論在動物（Xiong et al.， 2007; Zhang et al.， 2008）或人類（Cahill & McGaugh， 1998; Canli et al.， 2002; Lang， 1968， 1984）身上，大腦在結構與生物學層面皆存在性別差異。性別差異也表現在記憶、情緒與視覺等認知歷程上（Cahill， 2006）。 此外，個人特質如焦慮程度或憂鬱程度及其他人格特徵，也會影響人們如何感知並回應各類刺激（Coello & Cartaud， 2021; Iachini et al.， 2015）。因此，我們希望檢驗在情緒情境下，女性與男性在中性刺激價性評分上是否存在差異。同時，我們也想了解情緒特質對這些評分的影響，我們想探索情緒特質是否會改變個體在情緒情境下對中性圖片的評分方式。 本研究招募 82 位參與者，包括 41 位女性與 41 位男性。在作業開始前，所有參與者需完成相關的情緒量表，完成量表後，我們將從國際情緒圖片系統（International Affective Picture System，簡稱 IAPS）中挑選中性、負向與正向圖片。研究程序包含三種情境： 1. 中性情境：僅呈現中性圖片。 2. 負向情境：同時呈現負向與中性圖片。 3. 正向情境：同時呈現正向與中性圖片。 所有參與者皆從中性情境開始，參與者需對每一張圖片進行價性以及圖片的激發水準進行評分，在每個情境結束後，參與者皆需再次填寫相關的情緒量表。 行為結果顯示，重複量數變異數分析並未發現情緒情境對中性圖片評分具有顯著影響。然而，進一步以線性混合模型分析個體差異後發現，女性參與者在正向情境中對中性圖片給予較正向的價性評分，顯示女性較容易受到正向情緒情境影響；相同效果則未於男性參與者中觀察到。在激發水準評分方面，負向情境中的中性圖片評分顯著低於中性情境中的中性圖片，顯示情緒情境可能改變個體對中性刺激的激發感受。 生理資料結果進一步支持情緒情境對個體反應的影響。事件相關腦電位(event-related potentials， 簡稱ERPs）結果顯示，情緒情境下的中性圖片相較於中性情境下的中性圖片誘發較大的ERPs波形，表示中性刺激在情緒情境中可能獲得較多情緒或注意力資源投入。ECG結果顯示，SDNN指標受到情境影響，休息狀態與情緒圖片觀看情境之間呈現顯著差異，但pNN50未呈現相同效果。EMG結果則顯示，顴骨肌反應未在不同情緒情境間呈現顯著差異；然而，皺眉肌反應在負向情境中較為明顯，顯示負向圖片較能引發與負向情緒相關的臉部肌肉活動。 綜合而言，本研究發現情緒情境會影響個體對中性刺激的主觀評價與生理反應，且此影響可能受到性別差異調節。女性參與者在正向情境中對中性圖片產生較正向的評價，顯示情緒背景可能改變中性刺激的情緒意義。此外，ERPs、ECG與EMG結果亦顯示，即使主觀評價效果並非在所有條件下皆顯著，情緒情境仍可能透過神經與生理反應影響個體對中性刺激的處理歷程。;Emotion can be influenced by multiple factors， among which emotional context is one of the most important. Previous studies have used facial expressions to establish emotional contexts and found that participants’ valence ratings of neutral facial expressions vary depending on whether the context is negative or positive. Based on this finding， the present study aimed to examine whether exposure to a large number of negative or positive images would influence participants’ valence ratings of neutral images. Specifically， this study investigated whether different emotional contexts would lead participants to evaluate neutral images as more negative or more positive， thereby examining whether emotional context produces an assimilation effect or a contrast effect. In addition to emotional context， sex and individual traits also play important roles in influencing valence ratings of stimuli. A substantial body of literature has indicated that sex differences exist in the structure and biological mechanisms of the brain in both animals (Xiong et al.， 2007; Zhang et al.， 2008) and humans (Canli et al.， 2002; Cahill & McGaugh， 1998; Lang， 1968， 1984). Sex differences have also been observed in cognitive processes such as memory， emotion， and visual processing (Cahill， 2006). Furthermore， individual traits， such as anxiety， depressive tendencies， and other personality characteristics， may influence how people perceive and respond to different types of stimuli (Coello & Cartaud， 2021; Iachini et al.， 2015). Therefore， the present study further examined whether male and female participants differed in their valence ratings of neutral stimuli under emotional contexts. In addition， this study explored whether emotional traits modulate how individuals evaluate neutral images in emotional contexts. A total of 82 participants were recruited for this study， including 41 females and 41 males. Before the experimental task， all participants completed relevant emotional questionnaires. After completing the questionnaires， participants viewed neutral， negative， and positive images selected from the International Affective Picture System. The experiment consisted of three contexts: (1) a neutral context， in which only neutral images were presented; (2) a negative context， in which negative and neutral images were presented together; and (3) a positive context， in which positive and neutral images were presented together. All participants began with the neutral context. Participants were asked to rate the valence and arousal level of each image. After each context， participants completed the relevant emotional questionnaires again. The behavioral results showed that repeated-measures ANOVA did not reveal a significant effect of emotional context on valence ratings of neutral images. However， further analysis using linear mixed-effects models to examine individual differences revealed that female participants gave more positive valence ratings to neutral images in the positive context， suggesting that females may be more susceptible to the influence of positive emotional contexts. This effect was not observed in male participants. Regarding arousal ratings， neutral images presented in the negative context were rated as significantly less arousing than neutral images presented in the neutral context， indicating that emotional context may alter individuals’ perceived arousal of neutral stimuli. The physiological results further supported the influence of emotional context on individual responses. ERP results showed that neutral images presented in emotional contexts elicited larger ERP waveforms than neutral images presented in the neutral context， suggesting that neutral stimuli may receive greater emotional or attentional resource allocation when embedded in emotional contexts. ECG results showed that the SDNN index was influenced by context， with significant differences between resting states and emotional image-viewing contexts; however， pNN50 did not show the same effect. EMG results showed that zygomaticus activity did not differ significantly across emotional contexts. In contrast， corrugator activity was more pronounced in the negative context， indicating that negative images were more likely to elicit facial muscle activity associated with negative affect. Taken together， the present study suggests that emotional context influences individuals’ subjective evaluations and physiological responses to neutral stimuli， and that this effect may be moderated by sex differences. Female participants evaluated neutral images more positively in the positive context， indicating that emotional background may alter the emotional meaning of neutral stimuli. In addition， ERP， ECG， and EMG findings suggest that even when subjective rating effects are not significant across all conditions， emotional context may still influence the processing of neutral stimuli through neural and physiological responses.
