School of Psychological Sciences, University of Manchester, Manchester, UK.
School of Psychology, University of Liverpool, Liverpool, UK.
Psychophysiology. 2018 Apr;55(4). doi: 10.1111/psyp.13014. Epub 2017 Oct 12.
Emotional enhancement of free recall can be context dependent. It is readily observed when emotional and neutral scenes are encoded and recalled together in a "mixed" list, but diminishes when these scenes are encoded separately in "pure" lists. We examined the hypothesis that this effect is due to differences in allocation of attention to neutral stimuli according to whether they are presented in mixed or pure lists, especially when encoding is intentional. Using picture stimuli that were controlled for semantic relatedness, our results contradicted this hypothesis. The amplitude of well-known electrophysiological markers of emotion-related attention-the early posterior negativity (EPN), the late positive potential (LPP), and the slow wave (SW)-was higher for emotional stimuli. Crucially, the emotional modulation of these ERPs was insensitive to list context, observed equally in pure and mixed lists. Although list context did not modulate neural markers of emotion-related attention, list context did modulate the effect of emotion on free recall. The apparent decoupling of the emotional effects on attention and memory, challenges existing hypotheses accounting for the emotional enhancement of memory. We close by discussing whether findings are more compatible with an alternative hypothesis, where the magnitude of emotional memory enhancement is, at least in part, a consequence of retrieval dynamics.
情绪增强的自由回忆可能依赖于上下文。当情绪和中性场景在“混合”列表中一起编码和回忆时,很容易观察到这种情况,但当这些场景在“纯”列表中分别编码时,这种情况会减少。我们检验了这样一种假设,即这种效应是由于根据中性刺激是在混合列表还是纯列表中呈现,注意力对中性刺激的分配存在差异,尤其是在编码是有意的时候。使用经过语义相关性控制的图片刺激,我们的结果与这一假设相矛盾。情绪相关注意的众所周知的电生理标记的幅度——后极负波(EPN)、正后电位(LPP)和慢波(SW)——对于情绪刺激更高。至关重要的是,这些 ERP 的情绪调节对列表上下文不敏感,在纯列表和混合列表中观察到的结果相同。尽管列表上下文没有调节情绪相关注意的神经标记,但列表上下文确实调节了情绪对自由回忆的影响。注意力和记忆的情绪影响之间明显的分离,挑战了现有解释记忆情绪增强的假设。我们最后讨论了这些发现是否更符合替代假设,即情绪记忆增强的幅度至少部分是由于检索动态的结果。