Peters Jan, Daum Irene
Institute of Cognitive Neuroscience, Department of Neuropsychology, Ruhr-University Bochum, Germany.
Neurosci Lett. 2009 May 1;454(3):182-6. doi: 10.1016/j.neulet.2009.03.019. Epub 2009 Mar 11.
Remembering contextual aspects of an event (recollection) is an important function subserved by episodic memory. It has recently been shown that the electrophysiological correlates of recollection differ depending upon the type of information subjects retrieve from episodic memory. In the current study, we investigated whether electrophysiological correlates of memory are also affected by the type of source information retrieved from memory. Subjects studied words that were paired with a sound, a picture of a face or a picture of a scene. During test, they were required to judge whether a given probe word was new or old, and whether it had been paired with a sound, scene or face during study. The parietal old/new effect (400-700 ms post-stimulus), which has previously been associated with recollection, was larger for correct compared to incorrect source retrieval and of comparable magnitude for items from the different encoding conditions. A frontal positivity in the same time window, on the other hand, was sensitive to the type of information subjects retrieved from episodic memory, and showed a differential topography depending on memory content. Our findings confirm and extend previous observations by showing that, when recollection is assessed using an objective performance measure (i.e., source accuracy), frontal brain potentials are sensitive to episodic content.
记住事件的情境方面（回忆）是情景记忆所支持的一项重要功能。最近的研究表明，回忆的电生理相关性因被试从情景记忆中提取的信息类型而异。在本研究中，我们调查了记忆的电生理相关性是否也受从记忆中提取的源信息类型的影响。被试学习与声音、人脸图片或场景图片配对的单词。在测试过程中，他们需要判断给定的探测词是新的还是旧的，以及在学习过程中它是否与声音、场景或人脸配对。顶叶新旧效应（刺激后400 - 700毫秒），此前被认为与回忆有关，与错误的源提取相比，正确提取时更大，并且对于来自不同编码条件的项目，其幅度相当。另一方面，在同一时间窗口内的额叶正波对被试从情景记忆中提取的信息类型敏感，并且根据记忆内容显示出不同的地形图。我们的研究结果通过表明当使用客观表现指标（即源准确性）评估回忆时，额叶脑电对情景内容敏感，证实并扩展了先前的观察结果。
