Department of Psychology, University of Konstanz, Box D23, 78457 Konstanz, Germany.
Soc Cogn Affect Neurosci. 2011 Sep;6(4):450-9. doi: 10.1093/scan/nsq061. Epub 2010 Jul 2.
Subjective experience suggests that negatively arousing memories are harder to control than neutral ones. Here, we investigate this issue in an item-cued directed forgetting experiment. Electroencephalogram event-related potentials (ERPs) were recorded as participants viewed un-arousing neutral and highly arousing negative photographs, each followed by a cue to remember or forget it. Directed forgetting, that is reduced recognition of 'to-be-forgotten' items, occurred for neutral but not negative pictures. ERPs revealed three underlying effects: first, during picture viewing a late parietal positive potential (LPP) was more pronounced for negative than for neutral pictures. Second, 'remember' cues were associated with larger LPPs than 'forget' cues. Third, an enhanced frontal positivity appeared for 'forget' cues. This frontal positivity was generated in right dorso-lateral prefrontal regions following neutral pictures and in medial frontal cortex following negative pictures. LPP magnitude when viewing negative pictures was correlated with reduced directed forgetting, whereas both the enhanced frontal positivity for forget cues and the larger parietal positivity for remember cues predicted more directed forgetting. This study indicates that both processes of selective rehearsal (parietal positivities) and frontally controlled inhibition contribute to successful directed forgetting. However, due to their deeper incidental processing, highly arousing negative pictures are exempt from directed forgetting.
主观经验表明，负性唤起记忆比中性记忆更难控制。在这里，我们在项目提示定向遗忘实验中研究了这个问题。当参与者观看非唤起中性和高度唤起负性照片时，记录了脑电图事件相关电位（ERP），随后提示他们记住或忘记这些照片。定向遗忘，即对“要遗忘”的项目的识别减少，仅发生在中性照片上，而不是负性照片上。ERP 揭示了三个潜在的影响：首先，在观看图片时，负性图片比中性图片在后顶叶产生更大的正波（LPP）。其次，“记住”提示比“忘记”提示产生更大的 LPP。第三，“忘记”提示会产生更强的额部正性。这种额部正性在观看中性图片后出现在右侧背外侧前额叶区域，而在观看负性图片后出现在内侧前额叶皮层。观看负性图片时 LPP 的幅度与定向遗忘的减少相关，而忘记提示的额部正性增强和记住提示的顶叶正性增强都预测了更多的定向遗忘。这项研究表明，选择性复述（顶叶正性）和额叶控制抑制这两个过程都有助于成功的定向遗忘。然而，由于它们更深层次的偶然处理，高度唤起的负性图片不受定向遗忘的影响。
