The influence of working memory processes on the selective retrieval of episodic memory contents

从情景记忆中提取信息涉及重新激活在编码过程中活跃的感觉皮层表征。这种机制被称为觉醒，是有意识的回忆体验的重要前提。以前对脑电等神经成像技术的研究表明，编码阶段的感觉记忆内容在基于线索的检索的最初200毫秒内被皮质恢复。这支持了一个很大程度上是自动的和无意识的觉醒过程的理论。在此基础上，研究了情景记忆提取过程中皮层的恢复在多大程度上受到认知或自上而下的控制。这些研究的关键是工作记忆的概念，它使感觉信息的主动短期存储和对激活的记忆内容的认知控制成为可能。工作记忆内容的存储和认知操作，就像从情景记忆中提取信息一样，需要激活涉及编码各自信息的感觉区域。因此，这两种记忆过程要么以类似的方式在感觉皮层区域实现，要么基于相同的机制。因此，计划项目的前两个实验将调查工作记忆在从情节记忆中提取信息方面的作用。这将在实验的基础上进行调查，在这些实验中，测试参与者应该记住某些物体及其位置，以便以后检索。在编码阶段，对象将在工作记忆中进行认知操作。通过比较编码和提取阶段的(振荡)脑电模式，将检验情节记忆提取是否涉及纯感觉表征或更高级别工作记忆表征的早期重新激活。第三和第四个实验将调查记忆提取过程中的兴奋信息在多大程度上受到注意控制。在对视觉对象和空间位置之间的关联进行编码之后，将根据视觉线索选择性地忘记或记住这些关联。这应该需要在工作记忆水平上进行控制。基于神经振荡的测量和多变量解码技术，可以利用脑电来分析这一过程的时间特征。

The retrieval of information from episodic memory involves the reactivation of sensory cortical representations that were active during encoding. This mechanism is called ecphory and is an important prerequisite for a conscious recollective experience. Previous studies with neuroimaging techniques such as the electroencephalogram (EEG) have shown that sensory memory content from the encoding phase is cortically reinstated in the first 200 ms of cue-based retrieval. This supports the theory of a largely automatic and unconscious ecphory process. On this basis, it is investigated to what extent cortical reinstatement during episodic memory retrieval is under cognitive or 'top-down' control. Essential for these investigations is the concept of working memory, which enables active short-term storage of sensory information and cognitive control over activated memory contents. The storage and cognitive manipulation of working memory content, like the retrieval of information from episodic memory, entails the activation of the sensory areas involved in encoding of the respective information. Both memory processes are therefore either implemented in a comparable way in sensory cortical areas, or they are based on the same mechanism. The first two experiments of the planned project will therefore investigate the role of working memory in retrieving information from episodic memory. This will be investigated on the basis of experiments in which test participants should memorize certain objects and their position for later retrieval. During the encoding phase, the objects are to be cognitively manipulated within working memory. By comparing the (oscillatory) EEG patterns between the encoding and retrieval phases, it will be examined whether episodic memory retrieval involves the early reactivation of either purely sensory representations or higher-level working memory representations. The third and fourth experiments will investigate the extent to which ecphoric information during memory retrieval is subject to attentional control. After encoding associations between visual objects and spatial positions, these are to be selectively forgotten or remembered based on visual cues. This should require a control process on working memory level. The temporal characteristics of this process can be analyzed by means of the EEG, based on both the measurement of neural oscillations and multivariate decoding techniques.