運用系列情緒史楚普作業探討性侵害犯及正常控制組在情緒及認知上之交互運作：事件相關腦電位研究

Using Serial Emotional Stroop Tasks to Examine the Emotion-Cognition Interactions in the Sex Offenders and the Healthy Controls

周毓瑩(Yu-ying Chou)

指導教授 ： 洪蘭

國立中央大學/理學院/認知與神經科學研究所/碩士(2008年)

摘要

本研究運用多個情緒性史楚普作業（emotional Stroop task）探討選擇性注意力如何被不同情緒的刺激所影響，且藉由事件相關腦電位（Event-Related Potentials）的研究方法，進一步地檢驗連續性侵害犯是否較易被煽情刺激吸引，試圖找出性侵犯罪行為與大腦神經機制之間的關係。在情緒性史楚普作業中，受試者需忽略字詞的意義、儘快且正確地對字詞的墨水顏色做出反應。過去的研究結果發現：受試者對情緒字詞唸色的反應時間會比中性字詞的反應時間慢，此現象稱作情緒的史楚普干擾效應（Stroop interference effect）。一般認為此效應主要是因為：對不同情緒類別的字詞，受試者有不同的注意力分配。對情緒愈鮮明的字詞，我們愈會有注意力偏向（attentional bias）。本研究共進行了三個實驗來檢視正常控制組及性侵害犯受到不同情緒刺激的干擾程度，並加以探討兩組受試者上情緒和認知交互運作的情形。
實驗一及實驗2-1為行為實驗，分別使用口語和按鍵作為反應方式，主要對象為一般男性大學生，從反應時間的結果上發現：對於煽情字詞的反應時間顯著慢於中性字詞，顯示受試者會不自覺地受到煽情字詞的干擾，也就是將較多的注意力資源放在處理煽情字詞上。
實驗2-2進一步地紀錄及比較一般男性大學生在看到中性及煽情字詞時所伴隨發生的事件相關腦電位（ERPs），結果顯示無論是在早期或晚期的腦波成分上，都可看到受試者對於煽情字詞投入較多的注意力資源，尤其晚期的正向腦波(late positive potentials)更跟行為反應上的注意力偏向有顯著的正相關。實驗2-3將實驗2-2應用在連續性侵害犯上，結果發現連續性侵害犯跟正常控制組一樣對於煽情刺激會投入較多的注意力，但跟行為上的注意力偏向最有相關的腦波成分則是早期的N200，此結果顯示連續性侵害犯在處理這些煽情字詞的認知歷程上異於一般男性大學生。
實驗三將實驗刺激由文字改為圖片，我們依然操弄刺激的情緒類別，並且給予受試者反應上的時間壓力以避免可能的策略運用，企圖找出兩組受試者在處理煽情刺激時的反應時間及腦波振幅上是否有所不同。實驗3-1使用加上外框的彩色圖片，要求受試者忽略圖片意義，只對外框顏色做按鍵反應；結果發現負向及煽情圖片反應時間顯著慢於中性，但在控制實驗中也找到負向圖片慢於中性圖片的結果，代表顏色這類基本的知覺屬性仍會是實驗的干擾變項，因此在實驗3-2中我們將所有圖片以灰階的形式呈現，且同時紀錄受試者的腦波變化。結果指出，在正常控制組及連續性侵害犯的行為結果上都沒有情緒的主要效果；但在ERPs結果上，不論在早期（N200）或晚期（LPP）成分上，都可看到在煽情圖片情況下兩組受試者投注較多的注意力資源。更重要的，我們發現：這兩組受試者可能運用了不同的神經機制來處理這項作業，也就是在應對情緒會影響認知的情況下，兩組受試者有著不同型態的認知資源分配。
從這一系列情緒性史楚普作業中，我們發現正常控制組及連續性侵害犯在情緒效果上無明顯「量」上的不同；有趣的是，從腦波分布、相關上看到他們有「質」上的不同，因此我們就幾個可能因素做深入討論。
最後，關於未來的研究方向，我們試圖採用衝突更大的情緒史楚普作業，專門探討情緒上的衝突，進而檢驗在衝突監控、解決上，一般男性大學生和連續性侵害犯是否會有差異。

關鍵字

事件相關腦電位 ； 性侵害犯 ； 情緒和認知交互運作 ； 注意力偏向 ； 情緒史楚普作業

並列摘要

In the current study, a series of emotional Stroop tasks were used to examine the emotion－cognition interactions across the sex offenders and the normal controls. According to the previous research, the individuals with various emotional and drug-abuse disorders demonstrated attentional bias for the stimuli specifically related to their characteristics. Therefore, we employed the emotional Stroop paradigm including both versions of words and pictures (Exp. 2 & Exp. 3) to investigate whether the sex offenders showed the differential attentional bias effect compared to the controls while their brain potentials were measured.
In the experiment 2, we found the longer reaction time for the erotic words both in the sex offenders and the normal controls. The ERP results showed that the main effects of emotion on the P2, N2 and late positive potential (LPP) in the sex offenders while on the N2 and LPP in the controls. More interesting, due to the marginally significant interaction effect of emotion and group on the LPP component, this indicated the sex offenders seemed to pay less sustained-attention to the erotic words compared to the controls. We suggest that the sex offenders might use the deliberate regulation of the erotic influence. Furthermore, the positive relations between the LPP and the bias scores were significant in the controls. However, instead of the LPP, the N2 component positively correlated with the bias scores in the sex offenders.
In the experiment 3, behaviorally, there was no main effect of emotion in both groups, but the ERP results revealed that there were significant modulations of emotion on the early and late components, the N2 and LPP, in both groups. Furthermore, the differential scalp distribution patterns of emotional modulations on the two groups were found, that was, we found a significant three-way interaction effect (Caudality × Emotion × Group).
In summary, the current study demonstrated that the attentional bias effect occurred not only behaviorally but also in our brains. Namely, we found the emotional modulations on the ERP components. These indicate that the capacity-limited attention resource was voluntarily devoted to the emotionally salient events. More important, the different performances between the sex offenders and the controls may imply that there were differential neural mechanisms underlying the emotion－cognition interactions between the two groups. Further, the possible causes, implications, and directions for future research are discussed.

並列關鍵字

The emotion-cognition interaction ； The emotional Stroop task ； Attentional bias ； Sex offender ； ERP

參考文獻

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