競爭可好可壞：正負向情緒詞處理機制之差異

Abstract

許多的實驗證據顯示，帶有情緒意涵的刺激可以比中性的刺激進行更有效的處理；例如，正向與負向情緒詞比起中性詞有更好的辨識效果。然而，正負向情緒詞的處理歷程是否有所差別仍未知。我們進行了一系列實驗，以檢驗在單詞呈現和雙詞競爭情境下的正負向情緒詞處理歷程。在實驗一中，我們使用了Zeelenberg、Wagenmakers和Rotteveel（2006）二擇一強迫選擇的字詞辨識作業，但將刺激材料從英文詞彙轉換為中文的雙字詞，成功的複製了他們的結果。在實驗二中，我們將目標呈現階段的單詞改為同時呈現兩個詞（目標詞和競爭詞）。為了得到更純粹的情緒效果，我們在實驗二a與實驗二b中分別使用正向和負向詞來與中性詞搭配出現在目標畫面。結果發現負向詞相對於中性詞的注意力競爭優勢，而兩個正向詞一起呈現卻有著最差的表現。在實驗三中，我們將所有字詞的情緒類型（負向、正向和中性）放在同一個作業中。類似於實驗二的結果再一次被複製: 都是負向詞的配對有著最好的作業表現，然而都是正向詞的配對比起它與中性詞的配對卻有著較差的作業表現。在實驗四中，我們將點偵測作業（dot-probe task）增加到我們的二擇一強迫選擇作業中，藉此了解受試者的注意力分配狀況，結果發現若偵測點出現在負向詞的位置會有較快的反應，顯示注意力的確會轉移到負向目標詞的位置上。總結來說，負向詞會攫取我們的注意力，而正向詞會擴大我們的注意力廣度並增進對整體脈絡的處理效能。但是，正正得負，兩個正向詞反而會相互抵銷彼此的效果。我們認為這種差異可能是來自於正向詞與負向詞有著不同的注意資源分配。

Mounting evidence has shown that emotion-laden stimuli are processed more efficiently than neutral ones; for example, emotional words (negative and positive) are better identified than neutral words under data-limited conditions. However, it remains unclear whether negative and positive emotional words have the same or different processes. Here we report a series of experiments to examine whether there is a difference in processing emotional words with single words and with two competitive words. In Experiment 1, we replicated Zeelenberg, Wagenmakers, and Rotteveel (2006) ’s study by using a two-alternative forced-choice (2AFC) perceptual identification task but changed the stimuli from English words to two-character Chinese words. In Experiment 2, we presented two words (a target word and a competitive word) briefly in the target display to examine the processing of emotional words in the two-competitive-words condition. One positive or negative word was paired with one neutral word in Experiment 2a and 2b, respectively. Results showed a competitive advantage for negative target words. In contrast, positive target words were processed more efficiently when they were paired with a neutral competitive word than a positive competitive word. In Experiment 3, we mixed all types of emotional words (negative, positive, and neutral) in the same experiment. Similar results as in Experiment 2 were found: negative-negative pair had the highest accuracy and positive-positive pair had the lowest accuracy. In Experiment 4, we used a dot-probe task in addition to the original 2AFC task to examine the participants’ attentional distribution. Results showed a faster response to the dot-probe when it was presented at the location of the negative word, indicating its enjoyment of more attentional resource. The overall results suggest that while negative words capture attention, positive words expand attentional span and facilitate the whole context. However, sometimes more is less—the effects of two positive words offset each other. The different results of positive and negative emotional words may be caused by different allocation of attentional resources.