来源记忆中背景的情绪效价与唤醒对提取过程的影响

以往研究表明情绪背景对来源记忆存在影响，但背景的情绪效价和唤醒如何影响熟悉性及回想尚存争议。本研究以ERPs技术作为测量手段，采用来源记忆多键范式，操纵背景的情绪效价及唤醒强度，以探讨编码阶段背景情绪影响来源记忆提取的认知神经机制。学习阶段，呈现中性汉字及情绪图片（正性高唤醒、正性低唤醒、负性高唤醒、负性低唤醒）；测验阶段，仅呈现汉字，被试进行五键判断。行为结果发现：来源正确的比率比来源错误的比率更高，反应时更短；同时提取正性背景的辨别力更强，反应时更短；提取高唤醒背景反应时更短。脑电结果发现了分别代表熟悉性及回想的FN400及LPC新旧效应，且在500～700 ms，提取正性背景及高唤醒背景诱发显著更正的ERPs，但效价与唤醒没有交互作用。总体来说，来源记忆中背景效价及唤醒度对回想过程存在独立影响，体现为正性背景及高唤醒背景对来源提取的促进作用。

The Effect of Valence and Arousal of Emotional Contexts on Source Memory

Recent studies have shown that source memory can be modulated by emotional context. Here, we used ERPs techniques to explore the cognitive and neurological mechanisms of source retrieval under different valence and arousal contexts. During the learning phase, participants encoded a series of Chinese words superimposed on pictures of four different kinds of emotion. During the test phase, only the Chinese words were presented. Participants were instructed to press one of five buttons to indicate whether the word had been presented at the learning phase with a highly positive background, a mildly positive background, a highly negative background, a mildly negative background, or was a new word. Behaviorally, successful source retrieval showed a significantly higher ratio and shorter reaction time than the unsuccessful source retrieval. Higher memory performance was observed for positive contexts than negative contexts, and for highly arousal contexts compared to mildly arousal contexts. The ERP results showed that, there were significant FN400 and LPC old/new effects, which represented familiarity and recollection respectively. Meanwhile, we found greater LPC old/new effects for the retrieval of positive and highly arousal contexts compared to the negative and mildly arousal contexts. However, there was no significant interaction between valence and arousal. Together, these results suggest both the positive context and the high arousal context can facilitate the recollection of the source information. Valence and arousal may influence source memory via different cognitive mechanisms.