使用事件相关电位(ERP)技术和测试来源记忆的多键范式, 探讨不同情绪效价背景下来源提取的认知神经机制。学习阶段, 同时呈现汉字和3种效价情绪图片(重叠); 测验阶段, 只呈现汉字, 要求被试进行四键判断:旧字且背景为中性, 旧字且背景为正性, 旧字且背景为负性, 新字。结果发现:在提取阶段, 刺激呈现后300-500 ms, 3种情绪背景下来源判断正确项目和来源判断错误项目都比新项目诱发了更正的ERPs(即都存在新旧效应), 这一结果反映出刺激呈现后300-500 ms是一个早期的项目提取阶段, 它独立于来源提取。并且, 在中性背景下, 两种新旧效应没有差别; 而在正性和负性背景下, 来源判断正确项目的新旧效应显著大于来源判断错误项目。说明相比于中性背景, 情绪背景下被试可能更早对来源信息产生熟悉感。在500-650 ms, 3种情绪背景下都存在来源判断正确项目的新旧效应, 在来源判断错误项目和新项目之间没有显著差异, 来源正确与来源错误有显著的新旧效应差异, 但二者在头皮分布上是类似的, 这反映了晚期的来源提取过程。同时来源正确的新旧效应在这两个时段有显著不同的头皮分布, 表明这两个时段有不同加工过程。另外, 在500-650 ms, 存在显著的情绪效应, 正性背景下正确判断来源诱发的ERPs比中性和负性背景下的更正, 而且来源判断错误条件下没有情绪效应。综上所述, 来源正确和来源错误可能仅仅反映了大脑激活在量上的不同, 并不能推断两者存在质的差异; 大脑神经活动的早期不仅反映了对记忆项目的熟悉性, 而且也受情绪效应的影响, 500 ms之后大脑神经活动反映的是对记忆项目回想的过程, 这一回想过程也与情绪效应有关, 受到情绪效应的调节。
The interaction between recognition memory and emotion has become a research hotspot in recent years. Dual process theory posits that familiarity and recollection are two separate processes contributing to recognition memory. It has been hypothesized that item retrieval is based on both familiarity and recollection, whereas source retrieval relies solely on recollection. Event related potentials(ERPs) studies on recognition memory have identified two old/new effects that refer to familiarity and recollection, respectively. The mid-frontal old/new effect, occurring at approximately 300~500ms over frontal electrode sites, is attributed to familiarity. The parietal old/new effect, approximately 500~800ms maximal over parietal electrode sites, reflects recollection. In source memory paradigm, when both the item and source are remembered accurately, it is inferred that the memory decision is based on recollection. When correct item recognition is accompanied with an incorrect source attribution, it is posited that the memory decision is based on familiarity. Recent studies have discussed the interaction between source memory and emotion under “emotional context.”, and many studies have supported the theory that source retrieval is mediated by valence of emotional context. In the present study, we used ERPs techniques to explore the cognitive and neurological mechanisms of source retrieval under different emotional contexts while applying a source memory multiple-task paradigm. Subjects in our experiment were seven men and ten women. In the study phase, participants were asked to study a series of Chinese characters (item) with emotional pictures of three valences (source) appearing as the background of the items. Meanwhile, participants were told to press a button when an animal name was shown. In the test phase, only the Chinese characters were presented. Participants were instructed to press one of four buttons on the response box to indicate whether the word was presented at encoding phase with a ne