双加工再认提取中的情绪记忆增强效应

根据双加工理论, 再认提取可以划分为两种不同的加工：熟悉性与回想。以往的研究普遍认为情绪对再认提取具有增强效应, 但是情绪对再认记忆中两种不同加工方式(熟悉性与回想)的增强效应的神经机制尚存争议。本研究以ERP作为测量手段, 采用修正的“记得/知道”范式对情绪图片进行再认测验, 旨在探究在学习?测验间隔较长的条件下, 情绪信息如何对熟悉性与回想产生增强效应。在行为结果中, 对于知道判断, 情绪图片的记忆表现显著高于中性图片, 情绪效价间没有差异; 对于记得判断, 负性情绪图片的记忆表现要显著高于正性与中性图片。在ERP数据上, 对于知道判断, 情绪图片的FN400新旧效应有增强作用。对于记得判断, 负性图片的LPC的新旧效应波幅显著高于中性与负性图片; 而正性图片的LPC新旧效应增强作用不显著。以上证据表明：学习?测验间隔较长的情况下, 熟悉性再认提取中, 情绪记忆增强效应主要体现在情绪唤醒对记忆强度的提高, 而不仅仅体现在情绪效价对熟悉判断反应倾向的影响。在回想的再认提取中, 情绪效价的调节占据主导地位, 负性情绪图片有显著的情绪记忆增强效应; 正性情绪图片则不具有增强效应。

Emotional Memory Enhancement Effect in Dual-processing Recognition Retrieval

In studies of recognition retrieval, emotional memory enhancement effect was described as better memory performance for emotional stimuli than neutral ones. Based on dual-processing theory, recognition retrieval can be divided into two different processes: familiarity and recollection. Two important event-related potential correlates, the FN400 (a negative shift in frontal regions at 300~500ms time window), and the late positive complex (LPC; a positive peak over posterior regions at 500~800ms time window) was associated with familiarity and recollection, respectively. Some researchers considered that emotional memory enhancement effect occurred in recollection but not in familiarity. However, some indirect evidences showed that emotion could enhance memory strength in familiarity-based retrieval. Our research focused on two controversies: 1) whether emotion can enhance familiarity, and 2) how arouse and valence of emotion affect memory enhancement effect. In the current experiment, we used modified “remember/know” paradigm with ERPs recorded, to investigate how emotion influences familiarity and recollection in long-term study-test duration. Subjects were instructed to learn the pictures (including neutral, negative and positive pictures). And after one week, they made “remember/know/guess/new” recognition judgments towards stimuli intermixed with learnt and new pictures. Finally, the valence and arouse of experimental pictures were evaluated by the subjects participated in the experiment. Behaviorally, for studied pictures endorsed as “know”, the memory performances of emotional pictures were better than neutral ones, and there was no significant difference between emotional valences. As for the “remember” judgments, the memory performances of negative pictures were better than positive and neutral ones. ERP results show that, for the pictures judged as “know”, the FN400 old/new effects were significant in emotion condition but not in neutral condition, suggesting that emotion arousing enhanced familiarity-based retrieval. For pictures judged as “remember”, the LPC potentials of negative pictures were more positive than positive and neutral ones, showing that emotion valence modulated recollection-based retrieval. Our findings suggest that: in long-term study-test duration, emotional pictures could result in memory enhancement effect in the familiarity-based as well as the recollection-based retrieval. The emotional memory enhancement effect was not only modulated by the arousing as well as the valence of emotion. Emotional arousing played a predominant role in enhancing memory strength for familiarity-based retrieval. Emotional valence exerts influence exclusively on recollection-based retrieval in a way that only negative pictures could make enhancement effect on recollection.