Abstract: Most of researches consistently agree that memory enhancement effect is always activated by emotional stimuli. Then, how does the emotional feature of stimulus impact on intentional forgetting is still in argument. At present, directed forgetting (DF) paradigm, which including item method and list method was often adopted to explore the behavioral and cognitive neuroscience mechanism of intentional forgetting of emotional memory. Two distinct viewpoints from these researches dispute about whether the DF effect can be enhanced or weakened by emotional stimulus. One viewpoint suggests that this effect could not only be produced, but also be enhanced by emotional stimulus. Evidence from both behavioral and cognitive neuroscience studies showed that more selective coding could be obtained by emotional stimulus than by neutral one under remember condition, but the similar inhibitory occurred in both emotional and neutral stimulus under forget condition. The other viewpoint argues that DF effect could be weakened, even inhibited by emotional stimulus. Evidence showed that more attentional resource could be occupied by emotional stimulus than by neutral one, which leads to the enhanced memory of emotional stimulus and hard to forget. To summary the current literature, both objective factor with material types, emotional valence/arousal and subjective factor with emotional state of participants are involved in the important impacts of production of DF effect and its stability. Previous studies, for the material types, consistently indicated that compare with pictures, more stable and significant DF effect could be detected while words as experimental materials. Therefore, future studies need to select experimental material properly based on the aim of each study. The valence and arousal, as we know, are important dimensions of emotion. Most of results showed that there is a stable DF effect under neutral stimulus condition. Similarly, this effect could be detected under positive emotional stimulus condition. Further, there is no significant difference of effect cost between neutral and positive emotional condition. The DF effect, in contrast, can be influenced under negative emotional stimulus condition. In particular, this effect would be enhanced while participant is familiar with negative emotional stimulus. It would be weakened, conversely, while the arousal of negative emotional stimulus is high level. Furthermore, the emotional state of participant is also an important impact of the DF effect. Most of previous studies focused on the participants with mood disorder, such as depression, post-traumatic stress disorder (PTSD) and so on. Few studies with normal participants suggested that there is an interaction between emotionality of stimulus and emotional state of participant has impact on the DF effect. This kind of study, however, was lack of efficient monitory to the induced effect of participant’s emotion. Hence, future studies need to focus on the validity of effect of induced emotion, and ensure that whether the DF effect can be influenced by emotional state of participant or not. Directed forgetting is one of important components in the research field of memory. It partly reveals the mechanism of intentional forgetting. Further, researches on the DF of emotional memory are a benefit supplement to this field. According to review current literature, this paper highlights the importance of research on DF of emotional memory, and also proposes the constructive opinion to future studies.

Key words: directed forgetting effect, emotional stimuli, behavior, cognitive neuroscience

摘要： 刺激的情绪性具有增强记忆的效果，那么，带有情绪信息的刺激对遗忘又会产生怎样的影响？已有研究从行为及认知神经机制层面探讨了情绪性刺激对定向遗忘效应的影响，但结果并不一致。总结已有文献发现，以情绪性刺激的材料类型、情绪效价、唤醒度和熟悉度为主的客观因素和以被试的情绪状态为主的主观因素均为影响定向遗忘效应产生及其稳定性的重要原因。这类研究是对有意遗忘研究领域的重要补充，也加深了人们对有意遗忘机制的理解。

关键词: 定向遗忘效应, 情绪性记忆, 行为, 认知神经科学